tag:blogger.com,1999:blog-64409123258891097782024-03-13T07:24:56.005-07:00EAST Knowledge<i>E</i>nthusiasts <i>A</i>cquiring and <i>S</i>haring <i>T</i>echnical Knowledge in the east PDX area.EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-6440912325889109778.post-91280550111638769122017-04-15T10:12:00.000-07:002017-04-15T10:53:23.138-07:00Coffee Break #7Come join us for some “tech-talk” at the Gresham Library! It's been a little while since we last met, and EAST Knowledge is changing our overall format up a bit. We'd like to do more regular, informal gatherings and have talks when the opportunities present themselves.
<br/><br/>
So with that in mind, we hope you join us in this informal gathering to talk shop, show what we're working on, help each other, and hear from others interested in technology. If you are not yet familiar with our group, this is a nice opportunity to drop by and introduce yourself. We’ll have light refreshments, and some of us may get together for lunch afterwards. We look forward to seeing you there! <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Coffee Break</td></tr>
<tr><td><i>Where:</i></td><td>Large Meeting Room at the Gresham Library</td></tr>
<tr><td></td><td>385 NW Miller Ave, Gresham (<a href="http://www.openstreetmap.org/#map=17/45.50012/-122.43424">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:00am - Noon, Saturday, April 29th, 2017</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know with other tech enthusiasts</td></tr>
</tbody>
</table>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-80187178803568924892016-07-23T22:39:00.002-07:002022-03-29T08:53:57.691-07:00Recap "Replace Your File Cabinet with Mayan EDMS" (Meeting #8)<h3>"Replace Your File Cabinet with Mayan EDMS"</h3>
<p>
We had a great turnout for our 8th meeting, where James Richey was
kind enough talk to tell us everything he has learned about Mayan
EDMS. James did a wonderful job explaining why we would want to use
Mayan, how it manages documents, how to install Mayan and configure
it.
</p>
<p>
I neglected to take photos and screenshots as I was too busy trying to absorb as much
information as I could. I only have one poorly exposed photo, which
I've included. I will do my best to relate and capture what was
presented. As usual, the presenter is the best source, so please forgive my
inadequacies.
</p>
<div class="separator" style="clear: both; text-align: center;"><figure><a href="https://1.bp.blogspot.com/-qdbRj4kpxNs/V5QtwaHhTFI/AAAAAAAAAK0/M8Z0F30e17sVLMCuWMUwZC7Ya48_D4ATgCLcB/s1600/the-only-photo-i-remembered-to-take.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://1.bp.blogspot.com/-qdbRj4kpxNs/V5QtwaHhTFI/AAAAAAAAAK0/M8Z0F30e17sVLMCuWMUwZC7Ya48_D4ATgCLcB/s320/the-only-photo-i-remembered-to-take.jpg" width="320" height="240" /></a>
<figcaption style="font-size: 80%;">
James presenting Mayan EDMS while I snap a poorly composed photo of him. (<i>Sorry, James!</i>)
</figcaption>
</figure></div>
<h4>Motivations</h4>
<p>
James started the talk by discussing the various ways we can organize our documents. He was looking for something automated and computerized that provided personal control over his documents, made it easy to add new documents, and provided fast search for existing documents. James also wanted to avoid vendor lock in. He chose to invest time in Mayan because it is open source, free (as in cost), has good document organization features, will run on his personal server, and uses a simple file system based storage solution for the documents. That last feature mitigates the vendor lock in he is concerned about. Additionally, Mayan has a web based interface that can be operated by pretty much anything that has a browser, which makes it very accessible.
</p>
<h4>Key Concepts</h4>
<p>
James says that there are three key concepts behind the way Mayan views your documents:
<ul>
<li>Document type</li>
<li>Metadata</li>
<li>Indexes</li>
</ul>
Before attempting to deploy your Mayan instance, it is important to understand these concepts and to think about how to apply them to the documents that you need to manage.
</p>
<h5>Document type</h5>
<p>
The document type is about classifying your documents. What are the sorts of documents you deal with? Some examples document types: receipts, bills, and manuals. Whatever sorts of documents that you find yourself managing, Mayan should be able to accommodate you.
</p>
<h5>Metadata</h5>
<p>
Once you know your document types, you need to define the metadata that you want to attach to each document type. Metadata is just a "type" and a value, and they can be optional or required for a given document type. Some examples of metadata might be:
<table>
<tr><td><b>Type</b></td><td>:</td><td><b>Value</b></td></tr>
<tr><td>Date</td><td>:</td><td>2016-06-18</td></tr>
<tr><td>Project</td><td>:</td><td>Phoenix</td></tr>
<tr><td>Color</td><td>:</td><td>blue</td></tr>
</table>
</p>
<p>
When configuring a new Mayan instance, James recommends setting up your metadata first, then your document types. That way you can flesh out the document types with the metadata as you create them.
</p>
<h5>Indexes</h5>
<p>
Once you have document types and metadata types, you'll probably want to have convenient ways of viewing and getting to the documents that you have Mayan managing. That's where the indexes come in to play. The indexes allow you to organize documents based on metadata values. For example, you could place all the documents related to project Phoenix in one index.
</p>
<p>
The indexes are defined using Django templates. This means you have to understand both Django and Python to set up your indexes, which might be a bit of a learning curve for some. But it does give you a lot of power to create the indexes.
</p>
<h4>Searching</h4>
<p>
I don't recall exactly where James discussed this, but Mayan has very useful search facilities besides the indexes. My notes say that you should be able to also search on the content (assuming Mayan understands the content of your documents).
</p>
<h4>Other Features</h4>
<p>
I haven't covered all the features that James discussed in his talk. I neglected to mention tags, revision tracking, and metadata validation. James has said that he finds Mayan very useful for his purposes, and he hasn't even started to try to use the more advanced features, like the REST API, smart links, and staging folders. He also mentioned that there is a FUSE (Filesystem in Userspace) view of Mayan indexes available. This could make Mayan accessible in situations where http can't be used. Mayan seems to have plenty of room to grow for people or organizations that need help organizing and managing their documents.
</p>
<h4>Installing</h4>
<p>
Mayan EDMS is a Django application that would normally be installed on to a computer acting as a server. James has his instance installed inside of a "jail" running on his FreeBSD server. However, there are many ways to run Mayan including Linux "bare metal", virtual machines, or containers. The basic requirements are a machine capable of running nginx, PostgreSQL, and Python. If you don't feel like running your own server, you can pay to have somebody else run the service for you. As usual in open source, you have lots of options.
</p>
<div class="separator" style="clear: both; text-align: center;"><figure><a href="https://3.bp.blogspot.com/--l7N051PzRw/V5REePNCmQI/AAAAAAAAALM/ERw1EVu4T5wLEmgEl7XT5811Hqg-4-gWwCLcB/s1600/mayan_architecture.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://3.bp.blogspot.com/--l7N051PzRw/V5REePNCmQI/AAAAAAAAALM/ERw1EVu4T5wLEmgEl7XT5811Hqg-4-gWwCLcB/s320/mayan_architecture.png" width="320" height="203" /></a>
<figcaption style="font-size: 80%;">
Diagram of the architecture of Mayan from James' <a href="#references-and-resources">slides</a>.
</figcaption>
</figure>
</div>
<h4>Wrapping Up</h4>
<p>
James gave a great overview of Mayan and the demo worked
flawlessly. It's great to have a hands on demo after a presentation, since it gives us all a chance to try a few things out while the presenter is standing right there to handle questions. I know I learned a lot.
We'd all like to thank James for taking the time and efforts to give such a great presentation on Mayan EDMS. And we'd like to thank Gresham’s Multnomah County Library for hosting us once again.
</p>
<p>
We hope to see you next time! Until then, keep learning and sharing what you learn with others!
</p>
<h4 id="references-and-resources">References and Resources</h4>
<ol>
<li>James' slides:
<ol style="list-style-type: lower-alpha;">
<li><a href="https://drive.google.com/file/d/0B5OFTbq1WzXtX21aRWVYM2o3bTQ/view?usp=sharing&resourcekey=0-Fe0j0qLdyTQ1yejOX_83rQ">Original reval.js archive</a></li>
<li><a href="https://drive.google.com/file/d/0B5OFTbq1WzXtTS10d19Uc01rOTQ/view?usp=sharing&resourcekey=0-VMzbcjj9ijI2JHH8To01-Q">PDF format</a> (author conversion)</li>
</ol>
</li>
<li><a href="http://www.mayan-edms.com/">Mayan EDMS</a></li>
<li><a href="http://mayan.readthedocs.io/en/stable/">Mayan documentation</a></li>
<li><a href="https://groups.google.com/forum/#!forum/mayan-edms">Mayan's Google groups</a></li>
<li><a href="https://gitlab.com/mayan-edms/mayan-edms">Gitlab source and bug tracker</a></li>
<li><a href="http://www.freebsd.org/">FreeBSD</a>:
<ol style="list-style-type: lower-alpha;">
<li><a href="http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/jails.html">FreeBSD jails</a></li>
</ol>
</li>
</ol>
EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-33623589846460522742016-06-05T21:49:00.000-07:002016-06-05T21:49:52.548-07:00Replace Your File Cabinet with Mayan EDMS (Meeting #8 Announcement)<p>
EAST Knowledge is excited to host James Richey for our eighth meeting. Join us for James' talk sharing what he's learned about <i>Mayan EDMS</i>. There will be an interactive demonstration, <i>so bring your laptops!</i> <i>All</i> are welcome!
</p>
<table align="center">
<tbody>
<tr><td><i>What:</i></td><td>Replace Your File Cabinet with <i>Mayan EDMS</i></td></tr>
<tr><td><i>Who:</i></td><td>James Richey</td></tr>
<tr><td><i>Where:</i></td><td>Large Meeting Room at the Gresham Library</td></tr>
<tr><td></td><td>385 NW Miller Ave, Gresham (<a href="http://www.openstreetmap.org/#map=17/45.50012/-122.43424">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:30am - Noon, Saturday, June 18th, 2016</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know</td></tr>
</tbody>
</table>
<p>
Mayan EDMS is a free open source electronic document management system suitable for the home or office. It has powerful search and automatic categorization functionality. If you have you ever been frustrated while trying to locate an important document, been overwhelmed from attempting to organize a large stack of papers, or want to preserve your documents in digital form, you'll want to learn more about <i>Mayan EDMS</i>. James will:
</p>
<ul>
<li>Give an overview of Mayan EDMS and the problems it solves</li>
<li>Explain the key concepts such as metadata, document types, and indexes</li>
<li>Show how to import documents</li>
<li>Explore ways to quickly locate documents</li>
<li>Demonstrate Mayan EDMS with a live, interactive demo</li>
<li>Describe how to install and administer the software</li>
</ul>
<p>
Come and learn something new! We hope to see you there!
</p>
<h3>
Join us for lunch after!
</h3>
<p>
We're going to try something different for this meeting. After the talk, anybody who is interested can join us for lunch at Blondie's Pizza, which is a couple of blocks from the library. The last time I was there, they had a $6 lunch special for a salad and a slice of pizza. Blondie's is next to Jazzy Bagels on 112 N Main Ave (<a href="http://osm.org/go/WIDvEUMjJ?layers=N">map</a>).
</p>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-62213027545447612872016-03-23T22:07:00.000-07:002016-04-07T12:06:45.386-07:00Recap "The Joys and Sorrows of 3D Printing" (Meeting #7)<h3>"The Joys and Sorrows of 3D Printing"</h3>
<p>
For our seventh meeting, EAST Knowledge was delighted to host Michael Yurkoski on the topic of 3D printing. Michael presented a little bit of the history of additive manufacturing, quickly dived into the practical details of hobbyist 3D printing, and finished off his presentation with a live 3D printing demo. The presentation was a terrific, densely packed performance, and I think even people who had been doing 3D printing for a while learned something new. With the usual apologies for not being able to do the speaker justice with our meager notes, we will do our best to provide an overview of what was presented. Michael's slides are <a href="https://drive.google.com/file/d/0B5OFTbq1WzXtU3ZrUlIyYWRDd0U/view">here</a> and also available at the bottom of the post, and we recommend you check them out for more information.
</p>
<h4>Printer Lineup</h4>
<p>
Besides Michael, other people brought their 3D printers to show as examples of the different options available. This was a great supplement to the main talk as it gave us in the audience a good appreciation for the variety of printers available even when they all use the same technology.
</p>
<!-- Printer Lineup -->
<div class="separator" style="clear: both; text-align: center;"><figure><a href="https://4.bp.blogspot.com/-PeHl5_XsAsE/Vu7QVfR2OOI/AAAAAAAAAJ8/zZZfS2Y1y7YxNJOr5XTVL_eo_Kw8-QWSw/s1600/Printer-Lineup.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://4.bp.blogspot.com/-PeHl5_XsAsE/Vu7QVfR2OOI/AAAAAAAAAJ8/zZZfS2Y1y7YxNJOr5XTVL_eo_Kw8-QWSw/s320/Printer-Lineup.jpg" /></a>
<figcaption style="font-size: 80%;">
From left to right: David's upgraded printer, Pat's Printrbot Simple (with print bed insulation), and Michael's Printrbot Plus.
</figcaption>
</figure></div>
<h4>Additive vs Subtractive Manufacturing</h4>
<p>
Michael started off the talk by contrasting subtractive manufacturing with additive manufacturing. Subtractive manufacturing is where you start with more material than you need and then remove material until you've made what you want. Examples are CNC mills, routers, cutters, etc. Most of what people think about when they think of modern industrial manufacturing is subtractive.
</p>
<p>
Additive manufacturing is where you start with the raw material and build up a form a bit at a time. Industrial devices build up a form in layers. So you start with a design of an object, slice it into layers, and then build up the form a layer at a time. There are multiple technologies that can achieve this. See Michael's slides for the wide variety of 3D printer technology that is in use.
</p>
<p>
There are at least two main advantages to additive manufacturing over subtractive manufacturing: less waste and the ability to create forms that are impossible (or at least much more difficult) with subtractive manufacturing.
</p>
<h4>History of Additive Manufacturing</h4>
<p>
The first 3D printer that took digital design to reality was in 1984. These early machines would've been expensive. The first printer to break into the affordable hobbyist category was the <a href="http://reprap.org/">RepRap</a>. Steady progress has been made since then to the point that printers have become affordable and reliable enough that they are found in classrooms, offices, labs, and now in people's homes for their own personal use.
</p>
<h4>Current State of the Art</h4>
<p>
Most hobbyist printers are of the material extrusion (fused deposition modeling) variety. Or as Michael says, they extrude noodles, little plastic noodles. It is currently possible to get a decent 3D printer using this technology for around $500.
</p>
<p>
The typical material used for printing is either PLA or ABS. PLA has the advantage of being biodegradable and fumeless. ABS can be stronger, but generally gives off fumes and is not biodegradable.
</p>
<p>
Michael briefly gave an overview of the important hardware aspects of a noodle extruding 3D printer. They are:
<ul>
<li>Extruder</li>
<li>Stepper motors</li>
<li>Controller board</li>
<li>Print surface</li>
<li>Rigid frame</li>
<li>Filament</li>
</ul>
</p>
<h4>How Michael Uses His Printer</h4>
<p>
Michael primarily uses his printer to create useful objects for his own use. He either starts with existing designs and modifies them, or he creates all new designs himself. Some examples of things he has printed:
</p>
<ul>
<li>Mounting standoffs</li>
<li>AA battery dispenser</li>
<li>Pen holders</li>
<li>Toothbrush holders</li>
<li>Wrist brace</li>
</ul>
<p>
While Michael has been successfully printing lots of objects, he emphasized that 3D printing is more complicated than just how the printer works. While the technology has improved and continues to become more economical all the time, 3D printing isn't yet at the stage where you can just hop on down to the local store, pick up a printer in your price rage, take it home, and start printing things you find online or that you design yourself.
</p>
<p>
There are still many rough edges in the workflows and little standardization. For example, Michael often hand modifies the <a href="https://en.wikipedia.org/wiki/G-code">g-code</a> produced by his tools (usually to adjust speed if I remember). Many of the tools also have all options that you may ever need exposed to the end user, which makes it difficult to learn and also makes it possible to select inappropriate combinations of options. Michael mentioned a tool that has an option labeled "fix horrible". He's not sure what it does, but he leaves it checked. However, watching Michael work, it is clear that 3D printing is definitely at the stage that diligence and attention to detail will pay off in the final products.
</p>
<h5>Workflow</h5>
<p>
If you have a 3D printer, the typical workflow would be to design an object using a CAD tool. At this stage you will need to think ahead about how you intend the object to be printed. You even need to take into consideration aspects of the slicer tool. If you don't want to design something, then you can take an existing design from somewhere else and start with it.
</p>
<p>
After designing your object (or making a copy of an existing design), you import the object into a slicer program. This software is responsible for carving the object up into the layers we talked about before. It is also the tool that will allow you to decide how hollow your "solid" interiors will be. You can print your objects as mostly hollow with rigid support structures (see back lit photo below). You can also perform basic transformations in this tool. The slicer produces the g-code that is then fed to the printer.
</p>
<h4>Demo Time!</h4>
<p>
After finishing up the main talk, Michael connected his laptop to his printer. He started the warm up process on the print bed.
</p>
<!-- Michael with his example prints -->
<div class="separator" style="clear: both; text-align: center;"><figure><a href="https://2.bp.blogspot.com/-3JNm1CWcQ2c/VvC5Z964unI/AAAAAAAAAKg/uNEjc6CkLzsq_2544ysTBw073C6gG3_7g/s1600/Michael-with-his-pre-printed-examples.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://2.bp.blogspot.com/-3JNm1CWcQ2c/VvC5Z964unI/AAAAAAAAAKg/uNEjc6CkLzsq_2544ysTBw073C6gG3_7g/s320/Michael-with-his-pre-printed-examples.jpg" /></a>
<figcaption style="font-size: 80%;">
Michael preparing for the demo with example prints in the foreground.
</figcaption>
</figure>
</div>
<p>
While waiting for the print bed to warm up, he demonstrated the slicer software to us. His plan was to print a small coin which, according to the slicer, was going to only take seven minutes to print. He showed off the various transformations and adjustments that can be made inside the slicer (e.g. flipping axes or scaling up or down). He pointed out that even if you initially lack skill or confidence for designing objects, you can still achieve a lot by using existing designs and making adjustments in the slicer.
</p>
<!-- EAST Knowledge COIN Slicer -->
<div class="separator" style="clear: both; text-align: center;"><figure><a title="EAST Knowledge coin shown in the slicer" href="https://3.bp.blogspot.com/-v-MUTUmTh7Y/Vu7SHDrw5_I/AAAAAAAAAKI/9pmw6A-4ioYPomgI1RTk_dZ6OeKZ9ZE9g/s1600/EK-COIN-Slicer.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://3.bp.blogspot.com/-v-MUTUmTh7Y/Vu7SHDrw5_I/AAAAAAAAAKI/9pmw6A-4ioYPomgI1RTk_dZ6OeKZ9ZE9g/s320/EK-COIN-Slicer.jpg" /></a>
<figcaption style="font-size: 80%;">
The EAST Knowledge coin shown in the slicer.
</figcaption>
</figure></div>
<p>
Speaking of print beds, Michael talked to Pat about the modifications he had made to his printer. Pat had added insulation which he said allowed the print bed to warm up about ten times faster. Once the print bed was ready, Michael started the print. In the short video below, you can see a close up of the printer in action and hear the sounds it makes as it travels. You can also hear Michael and John talk about the quantity of plastic on the spool.
</p>
<iframe width="560" height="315" src="https://www.youtube.com/embed/uvKEoroAZzg?rel=0" frameborder="0" allowfullscreen></iframe>
<p>
As promised, the print job for the inch wide coin took about 7 minutes. Once it cooled, we had a nice new EAST Knowledge coin. The group got a kick out of passing around this newly manufactured piece. When you held it up to the light, you could see the support structures in the middle that allowed the coin to be hollow but still have rigidity.
</p>
<!-- EAST Knowledge COIN -->
<div class="separator" style="clear: both; text-align: center;"><figure><a href="https://2.bp.blogspot.com/-m8YGk-WQZKs/Vu7O2k-tP3I/AAAAAAAAAJ0/U_1mc7MFsvceF9DKZWIbInnDFOECiTI7A/s1600/EK-COIN.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://2.bp.blogspot.com/-m8YGk-WQZKs/Vu7O2k-tP3I/AAAAAAAAAJ0/U_1mc7MFsvceF9DKZWIbInnDFOECiTI7A/s320/EK-COIN.jpg" /></a>
<figcaption style="font-size: 80%;">
The freshly printed EAST Knowledge coin on the print bed. The ring around the coin is a skirt placed there by the slicer to help prime the extruder prior to starting the print job.
</figcaption>
</figure>
</div>
<!-- EAST Knowledge COIN Back Lit -->
<div class="separator" style="clear: both; text-align: center;"><figure><a href="https://4.bp.blogspot.com/-vPb4zwg99t0/Vu7O2vgywEI/AAAAAAAAAJw/6ND5EnUue_0aeru-PTBwX6XqEY1FPR7EA/s1600/EK-COIN-BackLit.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://4.bp.blogspot.com/-vPb4zwg99t0/Vu7O2vgywEI/AAAAAAAAAJw/6ND5EnUue_0aeru-PTBwX6XqEY1FPR7EA/s320/EK-COIN-BackLit.jpg" /></a>
<figcaption>
Holding the coin up to the light to see the hollow interior crisscrossed with support structures.
</figcaption>
</figure>
</div>
<h4>The Time Passed too Quickly</h4>
<p>
Michael packed a lot of information into his presentation and still managed to answer questions and run a successful demo. It was a lot of fun for the audience. We'd all like to thank Michael for taking the time and effort to present to the group. And we'd like to thank Gresham’s Multnomah County Library for hosting us once again.
</p>
<p>
We hope to see you next time!
</p>
<h4>References and Resources</h4>
<ol>
<li><a href="https://drive.google.com/file/d/0B5OFTbq1WzXtU3ZrUlIyYWRDd0U/view">Slides</a> from Michael's talk</li>
<li><a href="http://www.meetup.com/Portland-3D-Printing-Lab/">Portland 3D Printing Lab</a> - Portland 3D printing group on Meetup</li>
<li><a href="http://www.thingiverse.com/">Thingiverse</a> - design community focused primarily on 3D printable objects</li>
<li><a href="https://en.wikipedia.org/wiki/RepRap_project">RepRap</a> - <a href="http://reprap.org/">"humanity's first general-purpose self-replicating manufacturing machine"</a></li>
<li><a href="https://en.wikipedia.org/wiki/Polylactic_acid">PLA</a> - Polylactic acid is the biodegrable plastic commonly used in 3D printign</li>
<li><a href="http://www.bunniestudios.com/blog/?p=4641">Formlabs Form 2 Teardown</a> - Andrew (bunnie) Huang does a teardown of a 3D printer that uses vat photopolymerization</li>
<li><a href="https://en.wikipedia.org/wiki/G-code">G-code</a> - Language used to drive computer numerical controlled evices</li>
</ol>
EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-47038479139081211842016-03-02T20:39:00.000-08:002016-03-05T12:14:15.358-08:00The Joys and Sorrows of 3D Printing! (Meeting #7 Announcement)<p>
EAST Knowledge is excited to host Michael Yurkoski for our seventh meeting. Join us for Michael’s talk describing his experiences with using a 3D printer in the home. <i>All</i> are welcome!
</p>
<table align="center">
<tbody>
<tr><td><i>What:</i></td><td>The Joys and Sorrows of 3D Printing!</td></tr>
<tr><td><i>Who:</i></td><td>Michael Yurkoski</td></tr>
<tr><td><i>Where:</i></td><td>Large Meeting Room at the Gresham Library</td></tr>
<tr><td></td><td>385 NW Miller Ave, Gresham (<a href="http://www.openstreetmap.org/#map=17/45.50012/-122.43424">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:30am - Noon, Saturday, March 12th, 2016</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know</td></tr>
</tbody>
</table>
<p>
Michael has been doing an intense dive into the practical side of 3D printing, and he wants to share with our group the lessons he has learned. He intends to:
</p>
<ul>
<li>Give a brief intro into the history of hobby 3D printing</li>
<li>Explain why 3D printers are interesting</li>
<li>Expound on why 3D printers are loathsome</li>
<li>Explore how 3D printers work</li>
<li>Demonstrate how he designs a widget</li>
<li>Show off a printing like a pro (which Michael insists he is not)</li>
</ul>
<p>
We hope to have time for Q&A at the end. If you’ve been curious what all the fuss over 3D printers is about, or would like to commiserate with a fellow 3D printer enthusiast, join us for our meeting. We hope to see you there!
</p>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-24557478215601927672016-02-21T19:08:00.001-08:002016-02-21T19:32:29.502-08:00Coffee Break #6 - Recap<p>
It was a bright sunny Saturday, but we still had a great turnout for Coffee Break #6 at <a href="http://cafedelirium.net/"><i>Cafe Delirium</i></a>. We had several lively conversations going on at any one time, so I know I missed things. Feel free to let me know if there is anything I should include in the notes. These are the things that I remember:
</p>
<ul>
<li>PyBoard - Pat discussed his recent experience with the <a href="https://micropython.org/store/#/store">PyBoard</a>. The PyBoard runs a version of Python called <a href="http://micropython.org/">MicroPython</a>. Pat feels that the MicroPython environment provides a rapid prototyping and development environment that rivals the <a href="https://en.wikipedia.org/wiki/Arduino">Arduino</a>.</li>
<li>Repair Café - Gresham is having its <a href="https://greshamoregon.gov/repaircafe/">second Repair Café</a> on February 28th at the Gresham Library. They are looking for volunteer fixers who aren't afraid to roll up their sleeves and try to save useful things from our landfills.</li>
<li>East Metro STEAM Partnership - EAST Knowledge likes to keep tabs on local tech developments. Jim was filling us in about the latest happenings with the EAST Metro STEAM Partnership. They have recently had some successful grant applications which will be used to fill a Director position. I'm not sure where the official website is, but here is <a href="https://multco.us/ds4/east-metro-steam-partnership">option #1</a> and <a href="http://eastmetrosteampartnership.weebly.com/">option #2</a>.</li>
<li>Intel Hiring Policies - Apparently Intel has had a long standing policy of not rehiring people after they had been let go for performance reasons. Intel has recently extended this policy to cover people let go during layoffs. There has been some <a href="http://www.oregonlive.com/silicon-forest/index.ssf/2015/08/intel_layoffs_former_employees.html">controversy around this</a>.</li>
<li>David's 3D Printer - David has been working on upgrading his current 3D printer by printing the necessary parts. It looks like he has been making pretty good progress. (Picture of his bin is not representative of his progress.)<div class="separator" style="clear: both; text-align: center;"><a href="https://3.bp.blogspot.com/-r-FDFibI59s/VspyUMn8qrI/AAAAAAAAAJY/8bECbIwO4gA/s1600/david-3d-printer.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://3.bp.blogspot.com/-r-FDFibI59s/VspyUMn8qrI/AAAAAAAAAJY/8bECbIwO4gA/s200/david-3d-printer.jpg" /></a></div></li>
<li>Bill's Power Supply - Bill discussed plans he has for creating a modular power supply for his amplifier projects. The idea is to be able to build a single power supply that he can then reuse with different circuits.<div class="separator" style="clear: both; text-align: center;"><a href="https://2.bp.blogspot.com/-UxnItx6-i0c/VspyWwebevI/AAAAAAAAAJc/Sqq2nyAjYIA/s1600/power-supply-schematic.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://2.bp.blogspot.com/-UxnItx6-i0c/VspyWwebevI/AAAAAAAAAJc/Sqq2nyAjYIA/s200/power-supply-schematic.jpg" /></a></div></li>
<li><i>Andromeda Strain</i> - I don't remember how this came up, but somebody mentioned the movie <i>Andromeda Strain</i>. I haven't seen it (or read the book it is based on), but it sounds interesting (if dark). However, I don't know whether they were referring to the <a href="http://www.imdb.com/title/tt0066769/">1971 version</a> (<a href="https://www.youtube.com/watch?v=YMbSpnlOOtE">trailer</a>), or the <a href="http://www.imdb.com/title/tt0424600/">2008 TV mini-series</a> (<a href="https://www.youtube.com/watch?v=edUWhyQHhc8">trailer</a>). I'm pretty sure one of us suggested that the 1971 one was worth watching.
</ul>
<p>
That's all for now. Thank you to everybody who came out. It was good fun! If you couldn't make it this time, we hope to see you at one of our future meetings.
</p>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-42280675870225035042016-02-07T14:44:00.000-08:002016-02-21T19:14:12.096-08:00Coffee Break #6<b>Update: </b><a href="http://www.eastknow.org/2016/02/coffee-break-6-recap.html">A meeting recap.</a>
<br/><br/>
Come join us for coffee and “tech-talk” at Cafe Delirium! If you are interested in technology but are not yet familiar with our group, the coffee break is a nice opportunity to drop by and introduce yourself. We have the room in the back reserved. We're going to hang out for a couple of hours, so feel free to come by, talk shop, show off what you're working on, ask questions and pick each other's brains. We look forward to seeing you there! <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Coffee Break</td></tr>
<tr><td><i>Where:</i></td><td><a href="http://cafedelirium.net">Cafe Delirium</a></td></tr>
<tr><td></td><td>308 N Main Ave, Gresham (<a href="http://www.openstreetmap.org/?mlat=45.49977&mlon=-122.43074#map=18/45.49977/-122.43074">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:00am - Noon, Saturday, February 20th, 2016</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know over good coffee</td></tr>
</tbody>
</table>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-76824832184289580102015-11-29T16:18:00.000-08:002015-11-29T16:18:48.780-08:00Coffee Break #5 - Recap<p>
I apologize for the tardiness of the recap, but the Thanksgiving holiday got the better of me. Speaking of holidays, EAST Knowledge will be taking a break during December. We'll pick up again at the start of 2016. We'll announce more once we firm up plans. As usual, if you have a topic you'd like to share with the group, please don't hesitate to say so. We're a very welcoming and enthusiastic group!
</p>
<p>
We had a nice turn out for our fifth <i>Coffee Break</i> at the pleasant <a href="http://cafedelirium.net/">Cafe Delirium</a>. Pat brought his most recent incarnation of the head for his pick and place machine. You can see it below, but the camera on my phone does not do it justice. (Sorry, Pat!) We talked about a variety of things and enjoyed just chatting and catching up with each other. It was a good break!
</p>
<p>
Thank you, everyone, who came out for the coffee break! We hope to see you at our next event! Have a happy new year!
</p><div class="separator" style="clear: both; text-align: center;"><a href="http://1.bp.blogspot.com/-UylsRqSugnY/VluVgxy4RaI/AAAAAAAAAI8/lCrX267JABA/s1600/IMG_0296.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/-UylsRqSugnY/VluVgxy4RaI/AAAAAAAAAI8/lCrX267JABA/s320/IMG_0296.jpg" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/-xSX_mZ1h36M/VluVg6oIkjI/AAAAAAAAAJA/SpxjLWfzSwE/s1600/IMG_0297.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-xSX_mZ1h36M/VluVg6oIkjI/AAAAAAAAAJA/SpxjLWfzSwE/s320/IMG_0297.jpg" /></a></div>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-45758042862606578772015-11-08T13:22:00.001-08:002016-02-07T14:33:45.262-08:00Coffee Break #5<b>Update: </b><a href="http://www.eastknow.org/2015/11/coffee-break-5-recap.html">A meeting recap.</a>
<br/>
<br/>
We had a <a href="http://www.eastknow.org/2015/10/recap-going-back-in-time-for-some.html">great meeting</a> last month. For this month, we invite you to join us for coffee at Cafe Delirium. If you haven't made it to one of our talks, the coffee breaks provide a nice opportunity to drop by and introduce yourself. We have the room in the back reserved. We're going to hang out for a couple of hours, so feel free to come by, talk shop, show off what you're working on, ask questions and pick each other's brains. We look forward to seeing you there! <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Coffee Break</td></tr>
<tr><td><i>Where:</i></td><td><a href="http://cafedelirium.net">Cafe Delirium</a></td></tr>
<tr><td></td><td>308 N Main Ave, Gresham (<a href="http://www.openstreetmap.org/?mlat=45.49977&mlon=-122.43074#map=18/45.49977/-122.43074">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:00am - Noon, Saturday, Novemeber 21st, 2015</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know over good coffee</td></tr>
</tbody>
</table>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-45297212621086419922015-10-31T11:44:00.003-07:002016-03-21T20:47:02.543-07:00Recap "Going Back in Time for Some Vintage Howdunit" (Meeting #6)<h3>"Going Back in Time for Some Vintage Howdunit"</h3>
<p>
</p>
EAST Knowledge was pleased to host Bill Howland for its sixth meeting. The title of this meeting was “Going Back in Time for Some Vintage Howdunit”. Bill talked to the group about the earliest uses of vacuum tubes and some of the history of their development. We had a great turnout, but we’ll still try to summarize the talk to the best of our ability for those who couldn’t make it.
</p>
<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/-_pwTLoTDsx0/VjTy2s6M8wI/AAAAAAAAAHw/SPAQndCRDl4/s1600/IMG_6468.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-_pwTLoTDsx0/VjTy2s6M8wI/AAAAAAAAAHw/SPAQndCRDl4/s200/IMG_6468.jpg" /></a></div>
<h4>Some Early History</h4>
<p>
Bill discussed the discovery of “thermionic emission” which is what makes a vacuum tube possible. “Thermionic emission” occurs when you heat a material to a point that electrons are given enough thermal energy to escape the surface of the material. This effect was independently discovered by multiple people in the late 19th century.
</p>
<p>
Thomas Edison rediscovered it while working on his light bulbs. In Edison’s case his rediscovery coincided with an observation he made while working on a particular configuration of his light bulb. His incandescent light bulb had a filament just like the ones you are probably familiar with, but he had inserted an additional foil element that was not connected to the filament in any way. While the filament was heated (the light bulb was on), Edison noticed that he could cause current to flow through the foil element in one direction, but not in the other.
</p>
<div class="separator" style="clear: both; text-align: center;"><figure>
<a title="By User:Omegatron [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons" href="https://commons.wikimedia.org/wiki/File%3AEdisonEffect.svg"><img width="128" alt="Edison Effect" src="https://upload.wikimedia.org/wikipedia/commons/thumb/c/ce/EdisonEffect.svg/200px-EdisonEffect.svg.png"/></a>
<figcaption style="font-size: 80%;">
<a href="https://commons.wikimedia.org/wiki/File:EdisonEffect.svg">Simple schematic of Edison's bulb</a>
</figcaption>
</figure>
</div>
<p>
This basic observation that current was only flowing one way through the foil was called the “Edison effect”. You'll notice in the diagrams above that current flows between the foil and the filament only when the battery on the right has the correct orientation.
</p>
<h4>Basic Construction of a Vacuum Diode</h4>
<p>
These days any circuit element that only allows current to flow one way is called a diode. The vacuum tubes that Bill discussed in his talk were diodes. Similar to Edison’s experimental bulb, a vacuum tube diode contains a heated element (cathode) and a cold element (anode). The heated cathode and cold anode are separated by a vacuum. When the cathode is heated, the gap between the anode and cathode will behave like a diode. Well, a much less than ideal diode, but a diode nonetheless.
</p>
<div class="separator" style="clear: both; text-align: center;"><figure>
<a title="By Svjo (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons" href="https://commons.wikimedia.org/wiki/File%3ADiode-english-text.svg"><img width="200" alt="Diode-english-text" src="https://upload.wikimedia.org/wikipedia/commons/thumb/8/8e/Diode-english-text.svg/500px-Diode-english-text.svg.png"/></a>
<figcaption style="font-size: 80%;">
<a href="https://commons.wikimedia.org/wiki/File:Diode-english-text.svg">Diagram of vacuum tube diode</a>
</figcaption>
</figure>
</div>
<h4>Uses</h4>
<p>
Bill explained that one of the primary uses of a diode is for radio “detection”. A detector is often used to convert an AC (radio frequency) signal to a DC (baseband) signal. These diodes would have been used in radio receivers to detect signals from spark-gap, continuous wave (morse code), and AM transmitters. Another use for diodes is rectification. Power rectifiers are used to convert AC power into DC power as part of power supply circuits.
</p>
<h4>Other Interesting Tidbits</h4>
<p>
Vacuum tubes may have been electrical components, but Bill also described their interesting physical and mechanical construction. Since the operation of the vacuum tube relies on the absence of gas, an oxidizing metal is included inside the tube to help capture stray atoms of gas that may be lingering after the tube is evacuated. This oxidizing metal is referred to as a “getter” and is often seen as a metallic deposit on the surface of the glass.
</p>
<p>
Additionally, the mechanical separation of the filaments and anode and cathodes is critical to the operation of the vacuum tube. To keep the vacuum tube’s structure intact and rigid, mica spacers are often used. You’ll see those spacers at the top of the tubes in some of the photos.
</p>
<p>
Bill also mentioned how some of the higher voltage tubes that were used (e.g. in color TVs) would generate X-rays while in operation. These portions of the circuit would have been covered in a shielded box (thankfully) when in operation.
</p>
<h4>Reliability and Failure Modes</h4>
<p>
Bill noted that for low power, less complex gear like consumer radios, vacuum tubes are relatively reliable. You might need to replace a tube every three to five years. This seems to be on par with today’s consumer electronics with the advantage that you are able to repair the item instead of throwing it away once it breaks, as is typically done today.
</p>
<p>
However, due to the high voltages involved, vacuum tubes can have some spectacular failure modes. Here’s a picture of a tube that Bill brought that showed how the metal plate of the anode had been eaten away by arcing that had developed in the tube. Also noticeable is how the glass had deformed due to overheating.
</p>
<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/-f1govL6e7HQ/VjUKnb-7H6I/AAAAAAAAAII/nQ4_-9-i02I/s1600/IMG_6477.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/-f1govL6e7HQ/VjUKnb-7H6I/AAAAAAAAAII/nQ4_-9-i02I/s400/IMG_6477.jpg" /></a></div>
<h4>Demos</h4>
<p>
After the main talk, Bill proceeded to his demonstrations. He had brought a power supply that he combined with some simple circuits so that he could demonstrate the differences in voltage drop for the various tubes that he had in his collection. Differences in voltage drop are an indication of efficiency of the tubes, with lower voltage drops indicating more efficient operation.
</p>
<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/-LkVvjVy7GKo/VjUK5EhGu-I/AAAAAAAAAIQ/-ZbM1y4kM8M/s1600/IMG_6488.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/-LkVvjVy7GKo/VjUK5EhGu-I/AAAAAAAAAIQ/-ZbM1y4kM8M/s300/IMG_6488.jpg" /></a></div>
<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/-4tWDwBGA3EY/VjULJgicHfI/AAAAAAAAAIY/QTSEyxulc3U/s1600/IMG_6531.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/-4tWDwBGA3EY/VjULJgicHfI/AAAAAAAAAIY/QTSEyxulc3U/s300/IMG_6531.jpg" /></a></div>
<h4>Sometimes Technology Needs to Scale Up</h4>
<p>
Bill provided many examples of various types of tubes. After the talk and demonstrations, people were looking over the tubes. Bill pointed out that while tubes did continue to get smaller over time, their performance characteristics remained about the same. Additionally, unlike semiconductor transistors, vacuum tubes rate of shrinkage was very low. You don’t find the high rate of size reduction that has allowed semiconductor integrated circuits to double their transistor count every 18 months or so.
</p>
<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/-drI2sJ9tUZk/VjULSoHRKXI/AAAAAAAAAIg/leyJ3ciAFuY/s1600/IMG_6515.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/-drI2sJ9tUZk/VjULSoHRKXI/AAAAAAAAAIg/leyJ3ciAFuY/s400/IMG_6515.jpg" /></a></div>
<p>
At that point, somebody asked about modern applications of tubes. Bill mentioned audio amplifiers and Pat mentioned RF amplifiers used for broadcasting. Vacuum tubes are the technology of choice when you need high power combined with high bandwidth. Bill emphasized that vacuum tube technology can be readily scaled up for certain applications, which is an interesting contrast to semiconductor technology. Even in today’s world so focused on miniaturizing everything, sometimes it’s still important to be able to scale technology up and not just down.
</p>
<h4>That’s All for Now</h4>
<p>
It was a great talk, and we had a great time. We’d all like to thank Bill for taking the time and effort to present to the group. Bill has said that he is willing to come back and talk about other types of vacuum tubes and their applications. We intend to hold him to that offer!
</p>
<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/-6hbUBqPnCzc/VjULf7TQCiI/AAAAAAAAAIo/AzHPRmfgWpY/s1600/IMG_6481.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/-6hbUBqPnCzc/VjULf7TQCiI/AAAAAAAAAIo/AzHPRmfgWpY/s200/IMG_6481.jpg" /></a></div>
<p>
Thank you to Gresham’s Multnomah County Library for hosting us, and thank you to everybody who made it out! We hope to see you next time!
</p>
<h4>References and Resources</h4>
<p>
Bill didn’t get a chance to talk about “PSU Designer”, which is a program hobbyists use to simulate and verify their tube power supply designs. You can find that program here: <a href="http://www.duncanamps.com/psud2/index.html">http://www.duncanamps.com/psud2/index.html</a>.
</p>
<p>
Links to other resources:
</p>
<ol>
<li>Wikipedia entry on thermionic emission: <a href="https://en.wikipedia.org/wiki/Thermionic_emission">https://en.wikipedia.org/wiki/Thermionic_emission</a></li>
<li>Wikipedia entry on rectifiers: <a href="https://en.wikipedia.org/wiki/Rectifier">https://en.wikipedia.org/wiki/Rectifier</a></li>
<li>Wikipedia entry on vacuum tubes: <a href="https://en.wikipedia.org/wiki/Vacuum_tube">https://en.wikipedia.org/wiki/Vacuum_tube</a></li>
<li>Example of high power vacuum tubes: <a href="https://en.wikipedia.org/wiki/8974">https://en.wikipedia.org/wiki/8974</a></li>
<li>Bill’s website, “Evil Science Audio”: <a href="https://evilscienceaudio.wordpress.com/">https://evilscienceaudio.wordpress.com/</a></li>
<li>Wikipedia images:
<ol style="list-style-type: lower-alpha;">
<li>Edison Effect: <a href="https://commons.wikimedia.org/wiki/File:EdisonEffect.svg">https://commons.wikimedia.org/wiki/File:EdisonEffect.svg</a></li>
<li>Vacuum Tube Diagram: <a href="https://commons.wikimedia.org/wiki/File:Diode-english-text.svg">https://commons.wikimedia.org/wiki/File:Diode-english-text.svg</a></li>
</ol>
</li>
</ol>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-25768441689183437472015-10-11T10:01:00.000-07:002016-02-07T14:24:48.703-08:00Going Back in Time for Some Vintage Howdunit (Meeting #6 Announcement)<b>Update: </b><a href="http://www.eastknow.org/2015/10/recap-going-back-in-time-for-some.html">A meeting recap.</a>
<br/>
<br/>
<p>
EAST Knowledge is excited to announce it's sixth meeting. Bill Howland will re-introduce us to vacuum tubes and their uses. Come and learn something old!
</p>
<p>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Going Back in Time for Some Vintage Howdunit</td></tr>
<tr><td><i>Who:</i></td><td>Bill Howland</td></tr>
<tr><td><i>Where:</i></td><td>The Meeting Room at the Gresham Library</td></tr>
<tr><td></td><td>385 NW Miller Ave, Gresham (<a href="http://www.openstreetmap.org/#map=17/45.50012/-122.43424">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:30am - Noon, Saturday, October 24th, 2015</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know</td></tr>
</tbody>
</table>
</p>
<p>
Bill Howland will:</p>
<ul>
<li>Give a summary of the origins of vacuum and gas diodes and related thermionic devices</li>
<li>Have show-n-tell demonstrations of the earliest and simplest of such devices: The diode</li>
</ul>
<p>
Vacuum tube diodes were put to use in the early days of radio as "detectors", because they were more robust and reliable than crystal, mechanical, and chemical contrivances used for this purpose. With further development, thermionic vacuum and gas diodes advanced to be capable of power rectification with ever greater efficiencies.
</p>
<p>
Many example devices from the 1930's to 1950's will be available to examine. There will be orange, purple, and blue glows in the demonstrations!
</p>
<p>
Come and share what you know or just come to learn what other people know! <i>All</i> are welcome!
</p>
<p>
Bill shares some of his projects on his blog: <a href="https://evilscienceaudio.wordpress.com/">Evil Science Audio</a>
</p>
EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-22741900990132716052015-09-05T11:46:00.000-07:002015-11-08T13:23:33.037-08:00Coffee Break #4After taking a break over summer, EAST Knowledge is ramping up again with a coffee break. We invite you to join us for coffee at Cafe Delirium. If you haven't made it to one of our talks, the coffee breaks provide a nice opportunity to drop by and introduce yourself. We have the room in the back reserved. We're going to hang out for a couple of hours, so feel free to come by, talk shop, show off what you're working on, ask questions and pick each other's brains. We look forward to seeing you there! <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Coffee Break</td></tr>
<tr><td><i>Where:</i></td><td><a href="http://cafedelirium.net">Cafe Delirium</a></td></tr>
<tr><td></td><td>308 N Main Ave, Gresham (<a href="http://www.openstreetmap.org/?mlat=45.49977&mlon=-122.43074#map=18/45.49977/-122.43074">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:00am - Noon, Saturday, September 19th, 2015</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know over good coffee</td></tr>
</tbody>
</table>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-86279823541245443982015-05-17T21:14:00.000-07:002015-05-17T21:14:20.150-07:00Coffee Break #3 - Recap<p>
We held our third <i>Coffee Break</i> at the pleasant <a href="http://cafedelirium.net/">Cafe Delirium</a>. We had enough people show up that we may have to consider a location that can accommodate more people for next time. We forgot to take pictures again, but I did try to do a better job of taking notes.
</p>
<ul>
<li>Pat brought his <a href="http://www.acmesystems.it/arietta">Arietta board</a> to show us. He had attached a proximity detector on to the <a href="https://en.wikipedia.org/wiki/I%C2%B2C">I<sup>2</sup>C</a> bus. The proximity detector has a range of 5mm - 100mm. He is investigating incorporating the detector into his pick and place machine (previously discussed <a href="http://www.eastknow.org/2015/02/meeting-4-recap.html">here</a> and <a href="http://www.eastknow.org/2014/01/meeting-1-notes.html">here</a>).</li>
<li>
Pat also mentioned a youtube video which gave what he felt was an elegant explanation for capacitors in series. (I'm still tracking down that video, so I'll try to update this page when I get a link.)
</li>
<li>
We briefly discussed the pros and cons between Xilinx and Altera FPGA development tools and their different soft CPU cores.
</li>
<li>
We also talked about a desire to learn more about Linux containers and web development frameworks. Charles is using some of these things in his work, and utilized containers in the IPython notebook demo he <a href="http://www.eastknow.org/2014/06/meeting-3-recap.html">gave to the group</a>.
</li>
<li>
Michael thought to bring with him several examples of items he had printed from his 3D printer. He has been finding many uses for it.
<ul>
<li>
He discussed some of the pros and cons of the designs that can be found on <a href="http://www.thingiverse.com/">Thingiverse</a>.
</li>
<li>
He prefers to use Thingiverse for inspiration for creating his own designs as he has found he often cannot use the designs straight from the site.
</li>
<li>
He mentioned that he has discovered the importance of the interaction of the slicer software and the printer control software, and he has learned a lot about the work flow for 3D printing.
</li>
<li>
Michael pointed out that the company that produces his printer has just announced a smaller scale printer: <a href="http://printrbot.com/shop/assembled-printrbot-play/">Printrbot Play</a>.
</li>
</ul>
</li>
<li>We also discussed vacuum tube audio amplifiers and restoring other older equipment. Bill has found he can often find many pieces of older test equipment that can be had cheaply and just needs a little effort to get working again.
<ul>
<li>As we were discussing this, Chuck mentioned that at one time people actually installed phonographs into their cars. Something that most of us did not realize, and we were astounded that people would actually play their records while driving down the road. Virginia later dug up some <a href="http://www.consumerreports.org/cro/news/2014/04/record-players-were-the-infotainment-systems-of-the-1950s-and-60s/index.htm">internet evidence</a> of these entertainment systems.
</li>
</ul>
</li>
</ul>
<p>
That's everything from my notes, and I know these are just the highlights. If I've left anything out you'd like me to include, please don't hesitate to mention it.
</p>
<p>
I think everybody had a good time. The coffee breaks make a great opportunity for pleasant, wide ranging conversations. Thank you to everybody who came out. And if you couldn't make it, we hope to see you next time!
</p>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-75907511120367208672015-05-05T20:16:00.000-07:002016-02-07T14:26:40.532-08:00Coffee Break #3<b>Update:</b> <a href="http://www.eastknow.org/2015/05/coffee-break-3-recap.html">A meeting recap.</a>
<br/>
<br/>
EAST Knowledge is pleased to announce it's third "Coffee Break"!<br/><br/>
We invite you to join us for coffee at Cafe Delirium. If you haven't made it to one of our talks, the coffee breaks provide a nice opportunity to drop by and introduce yourself. We have the room in the back reserved. We're going to hang out for a couple of hours, so feel free to come by, talk shop, show off what you're working on, ask questions and pick each other's brains. We look forward to seeing you there! <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Coffee Break</td></tr>
<tr><td><i>Where:</i></td><td><a href="http://cafedelirium.net">Cafe Delirium</a></td></tr>
<tr><td></td><td>308 N Main Ave, Gresham (<a href="http://www.openstreetmap.org/?mlat=45.49977&mlon=-122.43074#map=18/45.49977/-122.43074">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:00am - Noon, Saturday, May 16th, 2015</td></tr>
<tr><td><i>Why:</i></td><td>Coffee and sharing what we know</td></tr>
</tbody>
</table>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-18244358707182323412015-04-21T21:38:00.000-07:002015-10-31T12:49:37.348-07:00Meeting #5 - Recap <h3>"Locating Intrusions Using Fiber Optics"</h3>
<p>
For its fifth meeting, EAST Knowledge was pleased to have Jim Rulla as its guest speaker. Jim previously spoke at EAST Knowledge for our second meeting, and he was gracious enough to come back. The topic of this meeting was “Locating Intrusions Using Fiber Optics”. As usual, we’ll do our best to report on the talk, but these summaries are in no way intended as a substitute to seeing the talks in person.
</p>
<p>
Jim, always an engaging speaker, opened his talk by showing the audience a front page news story from 2012 about a man whose jet ski had broken down while riding it New York's Jamaica Bay. The man swam three miles to shore and climbed the fence at the JFK airport without detection. It was a dramatic example of the importance of perimeter security, and an example of where the technology Jim was about to talk about could be applied.
</p>
<h4>Basics of Interferometry</h4>
<p>
Jim gave a basic description of interferometry. Interferometry is a way to perform high precision measurements on the order of wavelengths of light. Interferometry relies on the wave properties of light. When multiple waves are combined, they add together. This adding together can be constructive (when both waves are positive), or destructive (when one wave is positive and the other negative). A basic interferometer uses a laser source, a beam splitter, two mirrors, and a detector. Example from wikipedia:
</p>
<div class="separator" style="clear: both; text-align: center;"><figure><a href="https://commons.wikimedia.org/wiki/File%3AInterferometer.svg" imageanchor="1" title="By User:Stannered (Image:Interferometer.png) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/-c_v-WSRezqw/VTcaqeYh6nI/AAAAAAAAAEo/lmpCZKX7iV8/s200/Interferometer.svg.png" /></a>
<figcaption style="font-size: 80%;">
<a href="https://commons.wikimedia.org/wiki/File:Interferometer.svg">Diagram of a Michelson Interferometer</a>
</figcaption>
</figure></div>
<p>
The key to the interferometer shown above is that the light travels along two different paths but are recombined in the detector. Now if you move one or both mirrors, the path length of the two light beams will change. This will cause fringes to appear at the detector as the two light beams will be slightly out of phase with one another. If you are varying the position of the mirrors in time, the fringe patterns will also vary in time. Example fringe patterns:
</p>
<div class="separator" style="clear: both; text-align: center;"><figure><a href="http://1.bp.blogspot.com/-kEAoXAsWJRk/VTcdMLZWs7I/AAAAAAAAAE0/eUQmwHwPbXA/s1600/Colored_and_monochrome_fringes.png" title="See page for author [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/-kEAoXAsWJRk/VTcdMLZWs7I/AAAAAAAAAE0/eUQmwHwPbXA/s200/Colored_and_monochrome_fringes.png" /></a>
<figcaption style="font-size: 80%;"><a href="https://commons.wikimedia.org/wiki/File%3AColored_and_monochrome_fringes.png">Colored and monochromatic fringes in a Michelson interferometer.</a></figcaption></figure></div>
<h4>How Interferometry can be Used to Detect Intrusion</h4>
<p>
Jim had his custom software that he used to demonstrate the basic sort of signals that would be generated by a an interferometer. In the picture you see below, there are two large plots. The large plot on the bottom represents the position of one of the mirrors over time. The large plot on the top represents the signal that is detected where the two light beams come back together. As the mirror moves up and down (changing the path length the light travels), you can see the affect on the brightness of the light. Notice that when the mirror isn’t moving, the signal is flat (left side of plots).
</p>
<div class="separator" style="clear: both; text-align: center;"><figure><a href="http://1.bp.blogspot.com/-W9Fai3rAEQ4/VTcelEVPrJI/AAAAAAAAAE8/LvABEuECXBA/s1600/interferometry-display.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/-W9Fai3rAEQ4/VTcelEVPrJI/AAAAAAAAAE8/LvABEuECXBA/s320/interferometry-display.JPG" /></a>
<figcaption style="font-size: 80%;">
Top plot represents interferometer signal. Bottom plot is the mirror position. Notice that when the mirror isn’t moving, the signal is flat (left side of plots).
</figcaption>
</figure></div>
<p>
To detect an intrusion using interferometry, you would need an interferometer where an intrusion would disturb the path length of light. You can create an interferometer using fiber optics. If you then run the fiber optics along a fence (for example), any disturbance on the fence will cause a disturbance in the fiber optics. This in turn changes the path length of the light, which will create interference patterns that are then detected. In the absence of an intrusion, you have a flat signal. Once an intrusion occurs, the signal begins to change rapidly. Detecting when the signal is changing is all that is needed to detect the intrusion.
</p>
<p>
Jim also mentioned that basic interferometry makes it difficult to determine which direction the path length has changed. You’ll notice in the plot shown above that as the mirror changes direction, the output of the basic interferometer continues to change in the same way. However, modulating the light being used from the interferometer provides phase information. One possible way of doing that is by vibrating one of the mirrors. This technique is known as "homodyne modulation".
</p>
<h4>How Interferometry can be Used to Detect Location</h4>
<p>
Now that we have a basic interferometer detection, how can that be used to detect location? Jim showed a diagram (poorly) captured in the photo below. In the top, you see two fiber optic interferometers (one black the other red). These interferometers run in opposite directions in the same bundle of fiber. Because the interferometers are in the same bundle, what happens to one interferometer also happens to the other. If an intruder is climbing a fence, he will disturb both interferometers.
</p>
<p>
Because the interferometers are running in opposite directions, the signal produced by one interferometer is displaced in time relative to the other interferometer (see the red and black step plot in the picture below). This time difference varies depending on where the intrusion occurs. If you can calculate the time difference, then you can determine the location of the intrusion because you know the speed of light. <i>Pretty cool!</i>
</p>
<p>
In order to determine the time difference you have to perform a correlation on the two signals. The correlation isn’t perfect and can be computationally expensive, but using the correlation, you can get an estimate of the time difference between the intrusion signals.
</p>
<div class="separator" style="clear: both; text-align: center;"><figure><a href="http://4.bp.blogspot.com/-xQVacEfoHBA/VTchEPAOdNI/AAAAAAAAAFI/-UbtEngiePI/s1600/correlation-display.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/-xQVacEfoHBA/VTchEPAOdNI/AAAAAAAAAFI/-UbtEngiePI/s320/correlation-display.JPG" /></a>
<figcaption style="font-size: 80%;">
The two interferometers running in opposite direction are shown on top. In the middle you see a simple plot showing the interferometer signals from a single intrusion. Notice that the intrusion signals are offset in time.
</figcaption>
</figure>
</div>
<p>
Jim showed that with this method of determining location that there is a direct relationship between the speed of light and how rapidly you would have to sample the signals. For example, to try to get an accuracy of +/- 25 m, you have to sample the interferometer at least 10 MHz. He further emphasized that if you have a typical DSP running at 500 MHz, that you would only get 50 clock cycles per sample. That means that to properly process the incoming data, you need to have the appropriate model and the appropriate, efficient approach. Using his software, Jim showed off several different approaches to processing the signals. In one example he emphasized the processing speed. In another he emphasized the accuracy and certainty of the location calculation. He suggest that for this particular application it is possible to get both.
</p>
<h4>Afterwards</h4>
<p>
Both during and after the talk, the audience had a lot of great questions and made several astute observations. We also have some leads on possible future talks. For anybody who might be interested in discussing some tech topics that interest them, get in touch. You’ll find a receptive audience with EAST Knowledge. If you’re eager to share, we’re eager to learn.
</p>
<p>
We hope to see you next time for stimulating conversation. (We also have coffee, cookies, and Raspberry Pi.)
</p>
<iframe width="560" height="315" src="https://www.youtube.com/embed/ZgB7YtKmLiI?rel=0" frameborder="0" allowfullscreen></iframe>
<h5>References and Resources:</h5>
<ol>
<li>Link to jet ski story: <a href="http://abcnews.go.com/US/jet-skier-broke-jfk-airports-security-wanted-caught/story?id=17550202">http://abcnews.go.com/US/jet-skier-broke-jfk-airports-security-wanted-caught/story?id=17550202</a></li>
<li>More on interferometry: <a href="https://en.wikipedia.org/wiki/Interferometry">https://en.wikipedia.org/wiki/Interferometry</a></li>
<li>More on homodyne modulation: <a href="http://en.wikipedia.org/wiki/Homodyne_detection">http://en.wikipedia.org/wiki/Homodyne_detection</a></li>
<li>More on correlation: <a href="https://en.wikipedia.org/wiki/Cross-correlation">https://en.wikipedia.org/wiki/Cross-correlation</a>
<li>Patent on Intrusion Location: <a href="http://www.google.com/patents/US6621947">Apparatus and method for monitoring a structure using a counter-propagating signal method for locating events</a></li>
<li>Jim's talk for meeting #2, announcement and recap:
<ol style="list-style-type: lower-alpha;">
<li>Announcement: <a href="http://www.eastknow.org/p/events.html#meeting-2">http://www.eastknow.org/p/events.html#meeting-2</a></li>
<li>Recap: <a href="">http://www.eastknow.org/2014/03/meeting-2-recap.html</a>
</ol>
</li>
<li>Wikipedia images:
<ol style="list-style-type: lower-alpha;">
<li>Interferometer: <a href="https://commons.wikimedia.org/wiki/File:Interferometer.svg">https://commons.wikimedia.org/wiki/File:Interferometer.svg</a></li>
<li>Fringes: <a href="https://commons.wikimedia.org/wiki/File:Colored_and_monochrome_fringes.png">https://commons.wikimedia.org/wiki/File:Colored_and_monochrome_fringes.png</a></li>
</ol>
</li>
</ol>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-29213517002866928822015-04-04T17:47:00.000-07:002016-02-07T14:28:10.301-08:00Meeting #5 Announcement - Locating Intrusions Using Fiber Optics<b>Update:</b> <a href="http://www.eastknow.org/2015/04/meeting-5-recap.html">A meeting recap.</a>
<br/>
<br/>
EAST Knowledge is excited to announce it's fifth meeting. Jim Rulla will be giving a talk about how fiber optics can be used as sensors for locating intrusions. Come and learn something new! Come and share what you know! <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Locating Intrusions Using Fiber Optics</td></tr>
<tr><td><i>Who:</i></td><td>Jim Rulla</td></tr>
<tr><td><i>Where:</i></td><td>The Story Room at the Gresham Library (<a href="http://www.openstreetmap.org/#map=17/45.50012/-122.43424">map</a>)</td></tr>
<tr><td><i>When:</i></td><td><b>10:30am-Noon, Saturday, April 18th, 2015</b></td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know</td></tr></tbody>
</table>
<br />
<a href="https://en.wikipedia.org/wiki/Interferometry">Interferometers</a> measure distances to within fractions of the wavelength of light. Put a couple of these incredibly sensitive devices on the fence around an airport, and you can not merely detect a would-be intruder — you can locate him. Put a pair on a pipeline, and you can not merely detect nearby digging that could damage the pipe — you can locate its source. You might even be able to detect — and perhaps even locate — leaks in the pipe.
<br/>
<br/>
The detection and location mechanisms are fascinating examples of clever engineering. I'll explain how these patented systems work and illustrate new algorithms that improve performance.
EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-68201241630975235802015-03-31T21:41:00.001-07:002015-04-07T20:37:17.222-07:00Coffee Break #2 - Recap<p>
We held our second <i>Coffee Break</i> at the pleasant <a href="http://cafedelirium.net/">Cafe Delirium</a>. As usual, we had a friendly group show up. We forgot to take pictures this time, but that's only because we were engrossed in our conversations. I attempted to gather notes about what was discussed, but I admit that I didn't start taking notes until late into our conversations.
</p>
<ul>
<li>Discussed Jim Rulla's upcoming talk <i><a href="http://calagator.org/events/1250468066">Locating Intrusions Using Fiber Optics</a></i>. I hope to get an email announcement out in the next few days.</li>
<li>Discussed some of the differences and challenges between the industry in China and industry in the US.
<ul>
<li>Discused some of the strange economics that come into play. For instance being able to do three turns of a circuit board (assuming you have the time and right quantities) using manufacturers in China with less money than it would take to do a single turn in the US.</li>
<li>Andrew "bunnie" Huang's efforts to reverse engineer a SOC <a href="http://www.bunniestudios.com/blog/?p=4297">From Gongkai to Open Source</a>. Choice quote: "I want to be able to use a 364 MHz 32-bit microcontroller with megabytes of integrated RAM and dozens of peripherals costing $3 in single quantities, instead of a 16 MHz 8-bit microcontroller with a few kilobytes of RAM and a smattering of peripherals costing $6 in single quantities."</li>
</ul>
</li>
<li>Brought up how current chip manufacturing is handled by robots with the silicon wafers being placed and handled in large caddies (called <a href="https://en.wikipedia.org/wiki/FOUP">FOUPs</a>) where a single caddy of finished chips can represent several tens of millions of dollars. This reminded somebody of a video presentation that included a <a href="https://youtu.be/NGFhc8R_uO4?t=24m37s">clip of an incident in a plant</a>. (The whole video is worth watching.)</li>
<li>Discussed the use of <a href="http://cython.org/">Cython</a> which Pat may try to incorporate into a future talk.</li>
<li>Pat brought up how you can combine <a href="https://vgough.github.io/encfs/">Encfs</a> with a Dropbox-like service to create an encrypted volume that is synchronized to the cloud without the cloud being able to see what is stored.
<ul>
<li>This is easily used under Linux with <a href="http://fuse.sourceforge.net/">FUSE</a>, but apparently there is an equivalent option under windows called <a href="http://dokan-dev.net/en/about/">Dokan</a>.</li>
</ul>
</li>
<li>We briefly discussed the potential to use a <a href="http://www.raspberrypi.org/">Raspberry Pi</a> as a media center PC. It was also mentioned how easy it is to change the "personality" of a Raspberry Pi by swapping SD cards. This allows you to quickly repurpose a Raspberry Pi.
</li>
<li>Some amount of discussion about how small technology companies can contribute meaningfully to local economic development. We stressed how small companies and individual consultants often service larger companies.</li>
</ul>
<p>
That's all I can remember for now. If there's anything you'd like me to include, please don't hesitate to mention it. Thank you to everybody who came out. And if you couldn't make it, we hope to see you next time at one of our regular meetings!
</p>
EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-66391725974751820252015-03-08T20:43:00.000-07:002016-02-07T14:28:59.445-08:00Coffee Break #2<b>Update:</b> <a href="http://www.eastknow.org/2015/03/coffee-break-2-recap.html">A meeting recap.</a>
<br/>
<br/>
EAST Knowledge is pleased to announce it's second "Coffee Break"!<br/><br/>
EAST Knowledge is going to try a repeat of our first "Coffee Break". The first had a lot of great discussions. We invite you to join us for coffee at Cafe Delirium. We have the room in the back reserved. We're going to hang out for a couple of hours, so feel free to come by, talk shop, show off what you're working on, ask questions and pick each other's brains. We look forward to seeing you there! <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Coffee Break</td></tr>
<tr><td><i>Where:</i></td><td><a href="http://cafedelirium.net">Cafe Delirium</a></td></tr>
<tr><td></td><td>308 N Main Ave, Gresham (<a href="http://www.openstreetmap.org/?mlat=45.49977&mlon=-122.43074#map=18/45.49977/-122.43074">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:00am-Noon, Saturday, March 28th, 2015</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know and what we're up to</td></tr>
</tbody>
</table>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-76082405662298832022015-02-22T18:21:00.001-08:002015-04-07T20:37:17.227-07:00Meeting #4 - Recap<p>
To celebrate a year of EAST Knowledge, Pat Nystrom returned for <a href="http://www.eastknow.org/p/events.html#meeting-4">meeting #4</a> where he showed off two things:
</p>
<ol>
<li>Recent work on his pick and place machine</li>
<li>A DIY solder mask application</li>
</ol>
<p>
Pat is an engaging, knowledgeable speaker and he gave a tremendous talk. As usual, we’ll do our best to capture the meeting in these humble notes, but we won’t pretend to do the speaker justice. You really have to see these presentations in person.
</p>
<h3>Pick and Place Machine</h3>
<p>
When Pat <a href="http://www.eastknow.org/2014/01/meeting-1-notes.html">last talked</a> at EAST Knowledge he showed us his nearly completed pick and place machine. Pat’s goal is to produce a low cost pick and place machine for hobbyists and prototype assembly. He wants to combine what people do best with what machines do best. His pick and place machine will allow the human operator to pick up parts, while letting the machine perform final placement.
</p>
<p>
However, before finishing his machine, Pat was contacted to perform some other work that had extremely tight deadlines and required PCB assembly of multiple boards. The deadlines were so tight that he would not have been able to have the PCBs assembled by a manufacturing firm, so Pat turned to his mostly finished pick and place machine to assemble the boards himself. However, he found that while his current pick and place machine had buttery smooth motion when manually operated (as intended), it did not have the fine control he desired for part placement while being operated manually.
</p>
<h4>Manual Pick and Place</h4>
<p>
So Pat put together a new pick and place frame. For the two axes, this has rigid arms with small rollers that can be manipulated with the fingers for fine adjustment. Each axis has just enough stiction to keep from moving while the other axis is being adjusted. Additionally, Pat outfitted the parts head (taken from the previous machine) with a digital camera that he could use to see where the part was while placing it.
</p>
<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/-niWRRw9G1Ks/VOqLGTs9nkI/AAAAAAAAACY/jhl2oSfxKP4/s1600/pnp.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-niWRRw9G1Ks/VOqLGTs9nkI/AAAAAAAAACY/jhl2oSfxKP4/s320/pnp.JPG" title="Manual pick and place"/></a></div>
<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/-MoBIZRRFJcY/VOqLD4NLzZI/AAAAAAAAACQ/BWBSxpGqZsQ/s1600/pnp-pc.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-MoBIZRRFJcY/VOqLD4NLzZI/AAAAAAAAACQ/BWBSxpGqZsQ/s320/pnp-pc.JPG" /></a></div>
<p>
The machine isn’t perfect. For instance, the camera doesn’t have a perfect view of the part needle, so getting used to where the needle would place the part required a small learning curve. Despite the limitations, the machine allowed Pat to stuff 16 boards with small scale parts in about 4 hours without the fatigue and mistakes he would’ve experienced had he been using magnifiers and tweezers. Additionally, he successfully completed the prototypes. It’s hard to argue with success.
</p>
<p>
For the future, Pat would like to add a second camera to the head to provide a better view, and a laser dot that will provide an easy way to see where the part will be placed.
</p>
<h4>Lessons Learned</h4>
<p>
Beyond the technical issues, Pat felt he learned some valuable lessons while working on the manual pick and place. Being forced to work quickly required him to come up with ideas that he could try out quickly. This rapid pace allowed him to discover bad ideas earlier and discard them. Whereas before he was trying to get to product completion quickly, he is now thinking more along the lines of iterating his way to product refinement. Additionally, the manual pick and place is useful as it is right now even without all the automation. Focusing on having a useful product at each stage of development also allows for rapidly trying ideas.
</p>
<p>
It appears that the pick and place machine itself feeds into Pat’s entire process. It allows him to rapidly try ideas on not just the pick and place machine but also on the other things he works on.
</p>
<h3>DIY Solder Mask Application</h3>
<p>
After showing us his work on the pick and place machine, Pat gave a demonstration of a method he has developed for applying solder masks to his prototype circuit boards. Pat mills his own circuit boards, but the method will apply to any circuit boards you may make or have made. While you don’t need solder masks just for a prototype board, having a solder mask:
</p>
<ul>
<li>Improves the reliability of the board</li>
<li>Increases the lifetime of the board</li>
<li>Makes it easier to rework the boards</li>
</ul>
<p>
In short, it is often better to have a solder mask, so being able to apply a solder mask to boards you make yourself is a boon.
</p>
<h4>How it Works</h4>
<p>
Pat found a source of solder mask material that comes as a sheet. One side of the sheet is adhesive. This material is light sensitive, so Pat keeps it rolled up in a tube.
</p>
<h5>Required materials and tools:</h5>
<ol>
<li>Solder mask material</li>
<li>Solder mask stencil (it’s black everywhere you don’t want solder mask, i.e., over the component pads)</li>
<li>Exposure frame</li>
<li>Laminator (Pat used a Harbor Freight laminator)</li>
<li>UV Light source (Pat used a lamp that is normally used to cure finger nail polish)</li>
<li>Masking Tape</li>
<li>Exacto blade</li>
<li>Scissors</li>
<li>Latex gloves (mostly for cleanliness)</li>
<li>Canned air</li>
</ol>
<h5>Steps:</h5>
<ol>
<li>Warm up the laminator.</li>
<li>Wash PCB and dry with canned air.</li>
<li>Cut a piece out of the sheet of solder mask material to be bigger than your PCB. Pat used scissors to get a rough cut.</li>
<li>Using masking tape, attach to the dull side of the solder mask sheet, and pull off the protective covering. This exposes the adhesive side.</li>
<li>Apply the adhesive side to the PCB.</li>
<li>Use the exacto blade to trim off the excess material.</li>
<li>Run the PCB through the laminator. This will cause the solder mask material to adhere to the PCB surface.</li>
<li>Tape the stencil to the bottom of the exposure plate. Make sure the ink side of the stencil is away from the plate (which will be towards the PCB).</li>
<li>Close the exposure plate down over the PCB and align the PCB to the stencil.</li>
<li>Once the stencil and PCB are aligned. Clamp the exposure plate down so that the PCB won’t move.</li>
<li>Place the PCB into the UV light source for about 2 minutes. Let cure for another 5 minutes (optional).</li>
<li>Remove the PCB from the exposure frame, and lift the top protective sheet from the solder mask.</li>
<li>Use sodium carbonate and a brush to remove uncured solder mask material. Anywhere the UV light was blocked by the stencil should come right off.</li>
<li>Rinse the board again.</li>
<li>Enjoy your freshly solder masked PCB!</li>
</ol>
<p>
Pat was talking to the group as he demonstrated his method, but it looks like it only takes a few minutes of work to apply the solder mask.
</p>
<p>
Exposure Frame:
</p>
<a href="http://4.bp.blogspot.com/-ytpMZRaHwCU/VOqNNeDgmLI/AAAAAAAAACk/mlDx-EmhM94/s1600/exposure-frame.JPG" imageanchor="1" ><img border="0" src="http://4.bp.blogspot.com/-ytpMZRaHwCU/VOqNNeDgmLI/AAAAAAAAACk/mlDx-EmhM94/s320/exposure-frame.JPG" title="Exposure frame"/></a>
<p>
Stencil:
</p>
<a href="http://4.bp.blogspot.com/-Hxkz_BEvVyk/VOqNQFgM9PI/AAAAAAAAACs/j_V02m5HgWM/s1600/stencil.JPG" imageanchor="1" ><img border="0" src="http://4.bp.blogspot.com/-Hxkz_BEvVyk/VOqNQFgM9PI/AAAAAAAAACs/j_V02m5HgWM/s320/stencil.JPG" title="Stencil"/></a>
<p>
The UV source being applied to circuit board in the exposure frame:
</p>
<a href="http://4.bp.blogspot.com/-RkHA4BQXOQY/VOqNSjtnHwI/AAAAAAAAAC0/L14-vg9GOR0/s1600/uv-source.JPG" imageanchor="1" ><img border="0" src="http://4.bp.blogspot.com/-RkHA4BQXOQY/VOqNSjtnHwI/AAAAAAAAAC0/L14-vg9GOR0/s320/uv-source.JPG" title="UV Source"/></a>
<p>
The circuit board with solder mask applied. The green areas are where the solder mask stuck, and the copper areas are just the bare circuit board:
</p>
<a href="http://3.bp.blogspot.com/-y4-83f-E_LU/VOqNU1_UCqI/AAAAAAAAAC8/vEHQ52rik3U/s1600/solder-mask-applied.JPG" imageanchor="1" ><img border="0" src="http://3.bp.blogspot.com/-y4-83f-E_LU/VOqNU1_UCqI/AAAAAAAAAC8/vEHQ52rik3U/s320/solder-mask-applied.JPG" "Circuit Board with solder mask applied"/></a>
<p>
This was another excellent demonstration of Pat’s methods for quickly bringing his circuit ideas to life.
</p>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-17546137690174906442015-01-27T21:55:00.000-08:002016-02-07T14:29:56.773-08:00Meeting #4 Announcement - The Evolution of Hardware Design in the Home Lab<b>Update:</b> <a href="http://www.eastknow.org/2015/02/meeting-4-recap.html">a meeting recap</a>.
<br/>
<br/>
EAST Knowledge is pleased to announce it's fourth meeting. Pat Nystrom will be giving demonstrations on his efforts to make it easier to prototype electronics at home. <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>The Evolution of Hardware Design in the Home Lab</td></tr>
<tr><td><i>Who:</i></td><td>Pat Nystrom</td></tr>
<tr><td><i>Where:</i></td><td>The Computer Lab at the Gresham Library (<a href="http://goo.gl/maps/UxYU3">map</a>)</td></tr>
<tr><td><i>When:</i></td><td><b>10:30am-Noon, Saturday, February 14th, 2015</b></td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know</td></tr></tbody>
</table>
<br />
Pat Nystrom led off our EAST Knowledge series a little over a year ago, and we wanted to bring him back to see what he's been working on. He will be talking about and demonstrating two topics:
<ul>
<li>A dry-film soldermask process which makes home-made circuit boards much friendlier to use</li>
<li>An update on the development of his manual pick-place machine</li>
</ul>
Come and learn something new!
<br/>
<br/>
<a href="https://en.wikipedia.org/wiki/Solder_mask">Solder masks</a> are used in electronics manufacturing both to protect copper traces and to keep solder from going where it shouldn't.
<br/>
<br/>
<a href="https://en.wikipedia.org/wiki/SMT_placement_equipment">Pick and place machines</a> are devices used in electronics manufacturing. They come in various sizes, but they are commonly expensive. Pat is working on something that would be suitable and affordable for enthusiasts or prototype manufacturing.
EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-32413655519974945212014-11-23T14:11:00.000-08:002015-04-07T20:37:17.216-07:00Coffee Break - Recap<p>
EAST Knowledge's recent <a href="http://www.eastknow.org/p/events.html#coffee-break-1">"Coffe Break"</a> had a nice turn out. The Banaka & Browns shop provided a nice atmosphere to just relax and chat.
</p>
<div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/-bnqhFhl1jis/VHJZUyz8_kI/AAAAAAAAAB4/yn14pY93ENw/s1600/banaka-and-browns.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/-bnqhFhl1jis/VHJZUyz8_kI/AAAAAAAAAB4/yn14pY93ENw/s320/banaka-and-browns.jpg" /></a></div>
<p>
I won't presume to speak for everybody, but I definitely had a good time catching up with people, and it was great having the opportunity to meet new people. I think we will definitely do this again. Thank you to everybody who turned up, and for those of you who couldn't make it, we hope to see you next time.
</p>
<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/-Q7FJfjWjssM/VHJatPGpX1I/AAAAAAAAACA/zxfoSPWF3LE/s1600/group-shot.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-Q7FJfjWjssM/VHJatPGpX1I/AAAAAAAAACA/zxfoSPWF3LE/s320/group-shot.jpg" /></a></div>
<p>
We're heading into the busy holiday season, so we are planning another talk in January of the new year. We'll send out more information as we firm up the plans. As always, if there is a topic that excites you and you would like to share what you know about it, please get in touch. EAST Knowledge is a receptive, inquisitive audience.
</p>
<p>
Happy Holidays!
</p>
EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-4319613031194842252014-10-21T22:12:00.000-07:002016-02-07T14:30:47.486-08:00Coffee Break #1<b>Update:</b> <a href="http://www.eastknow.org/2014/11/coffee-break-recap.html">a meeting recap</a>.
<br/>
<br/>
EAST Knowledge is pleased to announce it's first "Coffee Break"!<br/><br/>
EAST Knowledge would like to do something a little more relaxed for our next meeting. We invite you to join us for coffee and pastries. We're going to hang out for a couple of hours, so feel free to come by, talk shop, show off what you're working on, ask questions and pick each other's brains. We look forward to seeing you there!<br />
<i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Coffee Break</td></tr>
<tr><td><i>Where:</i></td><td>Banaka & Browns Artisan Bakery and Coffee House</td></tr>
<tr><td></td><td>835 N Main Ave, Gresham (<a href="https://goo.gl/maps/7ZCjk">map</a>)</td></tr>
<tr><td><i>When:</i></td><td>10:00am-Noon, Saturday, November 8th, 2014</td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know and what we're up to</td></tr>
</tbody>
</table>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-8781547463227392382014-06-19T05:41:00.001-07:002015-04-07T20:37:17.231-07:00Meeting #3 - RecapCharles Stanhope led an informative and engaging discussion of
the IPython Notebook to an enthusiastic audience at the <a href="http://www.eastknow.org/p/events.html#meeting-3">third
EAST Knowledge meeting</a>. Charles has been using the Notebook to
good effect at work, and demonstrated several notebooks to the
audience. Charles has helped make his demonstration notebooks available. The notebooks are available on the <a href="http://github.com/eastknowledge/ipython-intro">EAST Knowledge github page</a>. You can also see static versions of the executed pages using the <a href="http://nbviewer.ipython.org/github/eastknowledge/ipython-intro/tree/executed/">nbviewer service</a>. The introduction notebook contains links to additional resources that may be useful if you wish to install IPython Notebook yourself.
<br/>
<br/>
<div class="separator" style="clear: both; text-align: center;"><a href="http://2.bp.blogspot.com/-XQYxK4wgNBE/U6LYsAcoJhI/AAAAAAAAABk/zhGd_23rpU0/s1600/charles-gesticulating.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-XQYxK4wgNBE/U6LYsAcoJhI/AAAAAAAAABk/zhGd_23rpU0/s320/charles-gesticulating.JPG" /></a></div>
<br/>
<br/>
With IPython Notebooks, individuals and groups can:
<ul>
<li>Rapidly prototype and explore algorithmic ideas</li>
<li>Easily share results</li>
<li>Replicate work</li>
<li>Freely collaborate</li>
<li>Leverage a large body of existing libraries</li>
</ul>
Alternatives to the notebook such as Mathematica or LabView are
expensive, so businesses often elect to purchase licenses for
only a few people — the Research and Development team, for
example. When it's time to share the results with those who do
not have access to the tools, the team has to prepare a report
— perhaps a (necessarily static) pdf. The report is a poor
substitute for an interactive demo. With a notebook, you can
delve into the code and experiment with the algorithms
yourself.
<br/>
<br/>
The IPython Notebook interface runs in your browser, and you don't need to
know any Python to view or modify the contents. Charles set up
a server running the IPython kernel on one laptop, and audience
members connected through a router using their browsers. The setup
demonstrated that IPython genuinely works cross-platform, and
that users need not install anything (except a browser) on
their local machines.
<br/>
<br/>
Notebooks consist of "cells" of different types:
<table>
<tr><td>Markdown</td><td> - for expository content</td></tr>
<tr><td>Code</td><td>- for actual computing</td></tr>
<tr><td>Headings</td><td>- for providing linkable sections</td></tr>
<tr><td>Raw</td><td>- for just raw text or for disabling code cells</td></tr>
</table>
<br/>
Code cells produce output that appears inline with the
document. Charles demonstrated a <a href="http://nbviewer.ipython.org/github/eastknowledge/ipython-intro/blob/executed/Karplus-Strong%20String%20Synthesis.ipynb">notebook</a> he developed to explore the
Karplus-Strong algorithm that Jim Rulla presented to the group
in our second <a href="http://www.eastknow.org/2014/03/meeting-2-recap.html">meeting</a>. The
algorithm synthesizes random input into sounds that sound
remarkably like plucked strings. You can adjust the pitch, see
the graph of the waveform, and play the sound in the notebook (even the <a href="http://nbviewer.ipython.org/github/eastknowledge/ipython-intro/blob/executed/Karplus-Strong%20String%20Synthesis.ipynb">static notebook</a> has a sound you can play).
Imagine how much more you'd learn — and how much more fun
you'd have — by playing with the algorithm than by simply
reading this description!
<br/>
<br/>
<div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/-Mb3DnELdXag/U6LYsKMY6PI/AAAAAAAAABg/wFnEOmixTpw/s1600/meeting-3-group.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://4.bp.blogspot.com/-Mb3DnELdXag/U6LYsKMY6PI/AAAAAAAAABg/wFnEOmixTpw/s320/meeting-3-group.JPG" /></a></div>
<br/>
<br/>
Other examples Charles developed include a csv
(comma-separated-value) file reader with data plots and a
Mandelbrot Set generator.
<br/>
<br/>
Tips:
<ul>
<li>The IPython and Python online help are helpful.
<ul>
<li>Type "help()" in a code cell to bring up Python's interactive help.</li>
<li>Click the "Help" menu item for much useful information.</li>
</ul>
</li>
<li>Press Enter to edit a cell, and ESC or <CTRL> + Enter to enter
"command mode". These and other keyboard shortcuts are
available under the Help menu item.</li>
<li>Use the Cell menu item to Run the code.</li>
<li>Pat Nystrom discovered that, if the kernel is running locally,
disabling the "inlining" of matplotlib brings up plot
windows with zoom buttons and scroll bars — a useful
discovery, indeed!</li>
</ul>
We'd like to thank the Multnomah County Library in Gresham for providing space and equipment for EAST Knowledge to meet.
<br/>
<br/>
<h4>Resources:</h4>
<ol>
<li><a href="http://github.com/eastknowledge/ipython-intro">http://github.com/eastknowledge/ipython-intro</a> - EAST Knowledge github page for notebooks</li>
<li><a href="http://nbviewer.ipython.org/github/eastknowledge/ipython-intro/tree/executed/">http://nbviewer.ipython.org/github/eastknowledge/ipython-intro/tree/executed/</a> - Static examples of executed notebooks</li>
</ol>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-26926728957180970472014-06-03T04:55:00.001-07:002016-02-07T14:31:37.967-08:00Meeting #3 Announcement - Introduction to IPython Notebook<b>Update:</b> <a href="http://www.eastknow.org/2014/06/meeting-3-recap.html">a meeting recap</a>.
<br/>
<br/>
EAST Knowledge is pleased to announce it's third meeting. Charles Stanhope will be giving a talk on IPython Notebook. <i>All</i> are welcome!
<br/>
<br/>
<table>
<tbody>
<tr><td><i>What:</i></td><td>Introduction to IPython Notebook</td></tr>
<tr><td><i>Who:</i></td><td>Charles Stanhope</td></tr>
<tr><td><i>Where:</i></td><td>The Computer Lab at the Gresham Library (<a href="http://goo.gl/maps/UxYU3">map</a>)</td></tr>
<tr><td><i>When:</i></td><td><b>10:30am-Noon, Saturday, June 14th, 2014</b></td></tr>
<tr><td><i>Why:</i></td><td>Sharing what we know</td></tr>
</tbody>
</table>
<br />
Come and learn about IPython Notebook interactive computing environment! An open source project used and developed by a community of scientists and engineers, IPython Notebook is a powerful tool that can save time and effort, and allows you to:
<ul>
<li>Rapidly prototype and explore algorithmic ideas</li>
<li>Easily share results</li>
<li>Replicate work</li>
<li>Freely collaborate</li>
<li>Leverage a large body of existing libraries</li>
</ul>
Charles will introduce and demonstrate IPython Notebook. He hopes to have a live system that can be used by the audience. All you will need is WiFi, a web browser, and some curiosity. So bring a laptop!
EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.comtag:blogger.com,1999:blog-6440912325889109778.post-53289702704625458192014-05-11T15:41:00.000-07:002015-04-07T20:36:46.421-07:00EAST Knowledge at East Gresham Community Information Fair<p>
EAST Knowledge will have tech enthusiasts and demonstrations at a table at the 7th annual East Gresham Community Information Fair,
</p>
<blockquote>
<table>
<tr><td><b>Wednesday, May 28, 2014</b></td></tr>
<tr><td><b>6:00 P.M. — 8:00 P.M.</b></td></tr>
</table>
</blockquote>
<p>
The fair is hosted by 3 of Gresham's Neighborhood Associations and will be held at:
</p>
<blockquote>
<table>
<tr><td><b>Greater Gresham Baptist Church</b></td></tr>
<tr><td><b>3848 NE Division St.</b></td></tr>
<tr><td><b>(Just East of Kane/257th)</b></td></tr>
<tr><td><a href="http://goo.gl/maps/nj1N7"><b>(google map)</b></a></td></tr>
</table>
</blockquote>
<p>
Please drop by to meet other tech enthusiasts, see what we've been up to, and find out more about our group!
</p>
<p>
The information fair is family-friendly, with exhibitors chock-full of information about — and opportunities in — our east-side community. To see a full list of exhibitors and other useful information, go to:
</p>
<p>
<blockquote>
<a href="http://greshamoregon.gov/neighborhoods">http://greshamoregon.gov/neighborhoods</a>
</blockquote>
</p>
<p>
and click on
</p>
<blockquote>
East Gresham Community Information Fair
</blockquote>
<p>
(last of the 4 links immediately under the "Neighborhood Associations" heading).
</p>EAST Knowledgehttp://www.blogger.com/profile/07933016967455475886noreply@blogger.com