Ben's Blog

It has been a while since my last post. Lots of stuff going on. Here’s a quick summary.

Earlier in the year I was elected to the board of directors at SkullSpace. It is really great to see all the things people are doing there and to be a part of making that happen.

For a while now I’ve been working on a bit of a side business. The idea is that we will develop, manufacture, and sell open source electronics. Ultimately, we intend to sell them with a pay-what-you-want model (with minimums) as well as pay-who-you-want (ie. allow the customer to direct where they want some of the profits to go; designer, influential projects, charities, etc). If you are interested, you can sign up for our mailing list on our website.

One of the first products I’ll be posting is an RGB LED ring display for a rotary encoder. Additionally, it adds capacitive sensing to the encoder so it can tell when the user is touching the knob. The firmware is still a work in progress, but I made a simple demo video to showcase the basic features.

RGB Rotary Encoder Display Demo from Benjamin Bergman on Vimeo.

Introducing the μJoypad, the worlds smallest NES controller! Measuring in at 25.4×12.8×3.2mm (1.0×0.5×0.1in) this is, by my best research, the worlds smallest, fully functional NES compatible controller. A couple months ago I saw an article or video of the world’s largest game controller and thought to myself “I bet I could make the smallest” and so I did. The project is open hardware and available on GitHub. More pictures and a description of the design process after the jump.

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I got some PCBs in the mail yesterday! I designed these all with gEDA pcb and had them manufactured in the States by OSHPark. In the main picture, from top to bottom, I have an FFC breakout board for my Bluetooth Kinesis project, an ATtiny45 VUSB breakout board intended to be used as a NES controller to USB adapter, an EasyPoint breakout board also for my Kinesis mod, and my μJoypad. I’ve already found one problem with EasyPoint breakout (my own fault, even though I was warned about it). gEDA pcb outputs 2 drill files, one for each of plated and un-plated holes, but OSHPark expects those to be combined, so my unplated holes were not drilled. Hopefully this is an easy fix with a drill press, otherwise I will just be cutting off the stabilizer pegs from the EasyPoints.

As some of you are aware, I am a member of the University of Manitoba SAE (Society of Automotive Engineers) Formula Hybrid team. The major project that I have been working on for a while now is a CAN bus controller Arduino shield. The system is based on the one designed by Mike Sefton last year. We are using the same CAN interpreter because the manufacturer was generous enough to donate some chips to us. These chips work well, but they are designed to be used with an OBDII reader, so we are using a few work arounds to get the system to work for us the way we need.

Aside from some simple changes to the circuit, there are two major changes to the system. First, I added a the NUP2105L chip to the CAN bus to give us some over-voltage protection. The major cause of failure last year was over-voltage, which is always a concern when dealing with electric vehicles. The second change was to allow an outside system to communicate with the CAN controller over a serial connection. Last year the CAN devices were controlled directly by the Arduino, but this year the Arduino is basically a middle man that can do some processing of commands if needed.

For the hardware design, I decided to try out a few open source tools. I first tried KiCad because it was more cross platform and a fully integrated suite. There were some things I didn’t like about it though (although I may have just been looking in the wrong place for the feature I thought was missing) so I decided to try out gEDA. I personally liked the feel of gschem better than KiCad’s schematic editor, and the PCB software seemed quite good to me too. The workflow between tools is a bit less intuitive, requiring a few terminal commands, but I am quite comfortable with the command line, so I can see myself using gEDA much more in the future.

The files for the hardware design are posted here: HARDWARE

The firmware for the Arduino is posted here: FIRMWARE

The firmware is currently a very basic repeater but will likely see changes once we start figuring out what specific features we will need. Feel free to post a comment or send me an email if you have any questions about the design.