CNC Build Club – Let’s Talk Stepper Motor Drivers.

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Stepper motor drivers are the things that power most of our DIY CNC projects.  There are dozens of choices.  What makes a good driver?  We will talk about that.

I will bring as many as I can find, which could be a dozen or more. Gecko’s, Leadshine DSPs, Pololu, Panucatt, Allegro, TI and others. I even have a three phase closed loop driver and motor.

 

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Special attention will be given to the Trinamic TMC261. This is a new-ish driver chip that has a lot of cool new features. The most interesting is it’s sensorless load detection. This means the driver can sense the load on the motor. This allows it to do a few new tricks. One is to dynamically adjust the current. You can set the maximum current quite high, but it will only go that high if the load on the motor requires it. This keeps the driver cool, yet allows it to power through higher loads and accelerations. The other trick is stall detection. If the motor totally stalls this is sensed and a fault pin is activated. This is being used by people to eliminate end stop switches. Rather than using pots and pins to set these values, you use and SPI bus. The driver also has a very high voltage range for a chip this size of 9-60VDC. Stepper motors love higher voltages

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I have a eval board we can play with.  This board has a motion controller on board and can take the steppers up to ludicrous speeds.


The CNC Club is a monthly meeting of Chicago area people passionate about learning, building and using digital fabrication equipment.  It is held at the Pumping Station One Hackerspace.  It is open to non members.  We also have a Google Group calledCNC Build Club.

 

04

08 2014

Pumping Station: One at the South Side Mini-Maker Faire

Pumping Station: One was at the Chicago South Side Mini Maker Faire next to the Ford City Mall this weekend teaching people how to build Noise-o-Trons.

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Thanks to the volunteers who came out and helped us, and to everyone who attended the faire! It was a big success, and we couldn’t have done it without you. We hope to see everyone again next year. We had a lot of kids and adults alike come through and build circuits with us!

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Special thanks also goes to the participants of our Pre-Maker Faire Poker Night!

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Poker Night was a huge success! We had a great time playing, and we raised some money to help pay for the Noise-o-Tron kits we used at the Maker Faire. Congratulations to the winners of the raffle.

 

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Some of us also stopped by the teen hackerspace Level Up inside the Ford City Mall.

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They put a lot of effort into helping organize the Maker Faire, so check them out!

03

08 2014

Fixing the Welcome Pi/Bone

Welcome TV

Welcome TV

When I first visited the space over a year and a half ago now, the first thing I saw when walking in the door was a big TV showing various information, including bus times and the space’s blog. I immediately wanted to know how it worked and was told it was transmitting through a Raspberry Pi. I would later learn how they worked and, recently, what that one was doing specifically. I have dubbed the TV the “Welcome TV” and whatever runs it similarly. Since then, the RPi has stopped transmitting successfully and I began to figure out to fix it, or rather replace it.

After research and lucky guesses, I found the software it was using was Screenly. The issue with Screenly is that its not open source and very limited in the free version. Also, after reinstalling it a few times, it doesn’t seem to like our network. So I decided to use something else. I found that a Beaglebone Black should do the trick with a program called Xibo. Both are more complicated and suitable than the RPi and Screenly.

So far, I have found that Xibo should work on a Beaglebone running Ubuntu, but have not had the chance to test it since Maker Faire Detroit was this weekend and have been busy with classes otherwise. It should get tested by the end of this week and I’ll know for sure if it will work. The Xibo team does not officially support it for RPi and assumingly Beaglebone either so I’m making it using forums and the seat of my pants. Which is arguably, the best way to make.

03

08 2014

Pumping Station: One Design Contest!

We’re looking for designs to turn into Tee-Shirts, Buttons, and Stickers for giveaways(buttons and stickers) and sale(tees) at Pumping Station: One! Draw, vector, and photoshop your heart out and show us what Pumping Station: One means to you!

The first wave is a call for submissions, this will last until the 31st of August, followed by an open voting period until the 30th of September. Finally, the board will order everything and get it shipped to the space.

Guidelines for submissions:

  • Designs are for the tees, buttons, and stickers. Unless you think the design will be optimized to look good in all three formats, I suggest you edit your designs for each application. By all means, have the same elements in each, but keep in mind that the button has less space for detail than the shirt.
  • Unless you’re designing in vector format, make sure your original copy will be of sufficient size and detail. the canvas you work in should be about 10″ wide by 15″ tall and at LEAST 400PPI.
  • Be excellant! No inappropriate themes, remember that PS: One is a safe space, and we don’t want to ban our own merch from the space.

Submit your designs to celtwolf@gmail.com

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07 2014

Group ShapeOko Build, Part Two!

The adventure continues! We had a great turn out at the last ShapeOko build event. Now it’s time to assemble the gantries and do some wiring. Join us this Wednesday July 30 from 7-10PM in PS:One’s shop to see the machine really take shape, and maybe we’ll get to see it move, too. Learn about open hardware and the ShapeOko 3D carving machine. This event is open to the public and is great for newbies and experienced CNC’ers, too.

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07 2014

Pre-Maker Faire Poker Night

Update V2!:  The grand prize will include a BeagleBoard.org Mesanger bag and BeagleBoard.org leather notebook (paper).

UPDATE: Prizes have been announced!
One prize will be the book Make an Arduino-Controlled Robot, part of the Make Projects book series. The grand prize will be a shiny new BeagleBone Black!

So, come on out, and try your luck! You just might be the winner of one of these amazing prizes!

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You are all invited to an exciting night of gambling-free poker!

Players of all skill levels are welcome! We will be playing Texas Hold ‘Em to raise money for the Noise-o-tron kits we will be teaching people how to build at the South Side Mini Maker Faire this Saturday. We provide this demo for free to Maker Faire attendees, and we’d like to keep it that way so we can help educate as many people as possible! Food will be provided; feel free to bring your own drinks.

So how does the gambling-free part work? The entry fee for playing at a table is $10, and you’ll get a stack of chips to play with. When you are done playing, you turn in your chips for raffle tickets. Each dollar in chips that you have will convert to 1 raffle ticket. At the end of the night, we will have a raffle for 1st and 2nd prizes. Don’t worry, you do -not- have to be present at the raffle drawing to win. As long as you’ve turned in your chips, you have a chance of winning. We will notify the winners via email, and you will get your prize ASAP. What prizes do we offer? You’ll just have to wait and find out! We promise that you’ll like them.

Also: We are looking for a third dealer. Justin and I will be dealing all night, but we would really appreciate it if someone would volunteer to help us deal another table.

Rules & strategy links for Texas Hold ‘Em

  1.  http://www.wsop.com/poker-games/texas-holdem/rules/
  2. http://www.wsop.com/poker-games/texas-holdem/strategy/

We will also have printouts of the rules at each table for reference. We look forward to seeing you there!

Where: Electronics Lab

When: Friday August 1st, 19:00-24:00; the raffle drawing will happen at midnight.

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07 2014

Women’s Electronics Workshop: Circuit Building on August 3

 

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Sunday, August 3, 1-5pm

Take a circuit from diagram to breadboard to finished project.

- Learn to Solder

- Read circuit diagrams

- Breadboard a circuit

- Design an LED circuit and solder it to perfboard.

Time: 4 hours
Price: $40
Materials fee: $10
Pre-reqs: none

This workshop is for participants who identify as female or genderqueer. Open to both members and non-members of Pumping Station: One.

Taught by Jesse Seay of Columbia College

Register for the workshop at the Women’s Electronics Workshop Meet Up Page.

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07 2014

NERP Tonite: The New Raspberry Pi B+, and The BeagleBone eQEP

NERP is Not Exclusively Raspberry Pi, the small computer and embedded systems interest group at Pumping Station:One in Chicago. NERP meets every other Monday at 7pm at Pumping Station:One, 3519 N. Elston Ave. in Chicago.

Tonight at NERP, Craig LeMoyne will introduce the new Raspberry Pi Model B+: the new and improved version of the highly successful Model B. We will have a side by side comparison with the Model B and highlight the changes.

Servo motors are computer controllable motors that do pretty much the same thing as stepping motors. From a systems perspective they have nothing else in common. Servos use feedback to adjust the motor’s position and velocity. The difference between the target speed (or position) and the measured speed (or position) is called error. Without error, the motor has no reason to move. The type of sensor usually used to detect a motor’s position is called a quadrature encoder. Although servo systems can give better performance than steppers in some situations, servos are more complex and more expensive than steppers. Part of the complexity is reading and making sense of the encoder. Adafruit has posted a video in which Drew Fustini has a good job of introducing some techniques for accessing the special eQEP quadrature decoder module in the BeagleBone Black.

https://www.adafruit.com/blog/2014/07/15/how-to-read-the-position-of-a-rotary-encoder-connected-to-a-beagleboneblack-txinstruments-beagleboardorg/

A PS:One member (me) has a project that aims to use the BBB’s eQEP to control an Etch-a-Sketch. Tonight I’ll show some of the technology that’s involved and progress on assembling the system.

Find NERP and Pumping Station:One at

NERP – Not Exclusively Raspberry Pi

Chicago, IL
246 members

NERP is Not Exclusively Raspberry Pi, the small computer and embedded systems interest group at Pumping Station One in Chicago. (Chicago’s oldest and finest hackerspace.) NERP…

Next Meetup

Bring questions, demos, personal research, etc. to share.

Monday, Jul 21, 2014, 7:00 PM
7 Attending

Check out this Meetup Group →

and http://pumpingstationone.org/

Doors open at 6:30pm. The next meeting is July 21st, 2014. NERP is free and open to the public.

Ed Bennett ed @ kinetics and electronics com

Tags: electronics,embedded, NERP, Open Source, raspberry pi,hackerspace, BeagleBone, Element14, Pumping Station One

 

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07 2014

The Internet’s Own Boy: The Story of Aaron Swartz

Come out to see the recently premiered documentary about the life and struggles of Aaron Swartz, Reddit co-founder and political activist.

From Wikipedia:

“Swartz was involved in the development of the web feed format RSS,[3] the organization Creative Commons,[4] the website framework web.py[5] and the social news site, Reddit, in which he became a partner after its merger with his company, Infogami.[i]

Swartz’s work also focused on sociology, civic awareness and activism.[6][7] He helped launch the Progressive Change Campaign Committee in 2009 to learn more about effective online activism. In 2010 he became a research fellow at Harvard University‘s Safra Research Lab on Institutional Corruption, directed by Lawrence Lessig.[8][9] He founded the online group Demand Progress, known for its campaign against the Stop Online Piracy Act.”

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There will be popcorn provided, and feel free to bring any snacks or drinks of your own. After the documentary showing there will be discussion, or people can hang out. This is a public event, so bring your friends!

Extra links:

Here is his blog: http://www.aaronsw.com/weblog/

One example of Aaron’s legacy: http://motherboard.vice.com/read/how-aaron-swartz-helped-inspire-lawrence-lessigs-mayday-pac

Legal analysis of the case: http://www.volokh.com/2013/01/16/the-criminal-charges-against-aaron-swartz-part-2-prosecutorial-discretion/

18

07 2014

Artificial Intelligence Q&A with Tim Winkler Follow-Up

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The event was a big success with over 30 people showing up to hear Tim answer questions about IBM’s Watson. Here are some pictures and sample questions (may be heavily paraphrased since they are drawn from my shoddy notes and memory) from the event:

Tim at QA2

Q: Can Watson pass the Turing Test?

A: Watson has never been given the Turing Test.

Q: Are there plans to build a physical analogue for Watson? (Asked multiple times)

A: No.

Q: Can you tell us about the specific details of what you do?

A: No, but after Watson was on Jeopardy IBM released detailed documentation

Q: Has anyone fed Watson info about itself?

A: No.

Q: There seems to be a competition between IBM and Google in the realm of AI. Do you believe that the future will include more mainframe-based AI’s like Watson or decentralized neural network based AI?

A: I’m a big fan of decentralized neural networks.

Q: How do you go about getting a job in AI?

A: I have a CS degree with an AI concentration, and I got an internship with IBM that eventually led to working on Watson. I worked on unrelated projects before this. There’s no set path.

Q: Is there any project to work on improving Watson’s ability to interpret history?

A: There are many NLP (natural language processing) projects that focus on solving that problem.

Q: Does one version of Watson know what other versions of Watson know? (i.e. medical student Watson vs cognitive cooking Watson)

A: No.

Q: Why is Watson so much better than Siri?

A: Siri is not really an AI aside from its NLP abilities.

Q: What question do you wish people would ask about Watson?

A: You guys ask good questions.

Q: Do you do unit tests and end tests on Watson?

A: Yes.

Q: Are there any Easter eggs in Watson?

A: I can’t tell you.

Q: Do you have a button that stops Watson if it turns into HAL?

A: We’ve had no serious thoughts of Watson turning on people.

Q: Watson does not have ontological understanding of the world; any benefit to adding that?

A: We’re working on it.

Here are some related links to the Q&A that Tim shared afterwards:

1.)    “Here’s the IBM research journal issue on Watson, that gives away all the tech secrets anyone would want”: http://ieeexplore.ieee.org/xpl/tocresult.jsp?reload=true&isnumber=6177717

2.) Behind a paywall:( “Computational creativity for culinary recipes”: http://dl.acm.org/citation.cfm?doid=2559206.2574794

3.)    “This is relevant to cognitive cooking, Florian Pinel is one of the authors, he’s our team lead”: http://arxiv.org/abs/1311.1213

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07 2014