Zigduino on Arduino IDE 1.5

I finally got around to porting the Zigduino files over to the Arduino-1.5.7 IDE... and it is wonderful.

Instead of being somewhat painful to install like the previous versions, it's just a zip file that you unpack in to the $SKETCHBOOK/hardware directory and restart the IDE. The Arduino-1.5.7 IDE also uses a current avr-gcc toolchain, so no mucking around with that either. I've pulled the ZigduinoRadio library into the distribution as well, so the new process is as follows:

  1. Download the zipball from Github.
  2. Unpack the zipball into the hardware subdirectory of your Arduino sketchbook directory
  3. Start the Arduino-1.5.7 IDE

And that's it!

RGB LED Matrix Customer Projects

A couple of my latest customers for the new RGB LED Matrix Backpack have done some pretty cool things with it. 

Steven programmed a gorgeous multi-color bouncing ball interaction with the aliasing tricks to increase the apparent resolution. This is one of the nicer video clips I've seen -- shooting things that glow is difficult to do well and Steven did a nice job here. 

Charles put together a neat little printable 3D snap-action clip that makes it really easy to connect backpacks together to build arrays of LED matrices. You can find the model on TinkerCAD.

Another op amp parameter to pay attention to...

I recently managed to build a non-inverting amplifier with an op amp that acted as an inverting amplifier. I found this more than a little puzzling, and asked around for possible causes. My friends were kind enough not to laugh too much when they pointed out my error. 

The problem was that the op amp I had selected, the TL974, has a rather tight common mode voltage spec. It expects the common mode input voltage to be more than a volt from each power rail. The common mode voltage is the average of the two input voltages. Since those voltages are equal (or nearly so) in the non-inverting configuration, we can assume that the common mode voltage is equal to the input voltage.   

The input voltages on my circuit ranged from 0-1.8V against power rails of 0V and 3.8V. Not surprisingly, this didn't work very well; it caused the inverting and non-inverting inputs to swap places. As a result, instead of amplifying the input voltage across the intended gain of two, it shifted the signal up 1.8V and inverted it. Wheeee!

Here's a long but useful discussion of this issue on Planet Analog.

Circuit pattern trading cards

Arachnid Labs has come out with circuit pattern trading cards. Most electrical circuits are composed from a relatively small number of common patterns that can be designed and analyzed as units. The engineer can then compose these individual sub-circuits into a completed device.  

Arachnid Labs took this and produced a set of 32 trading cards that illustrate some of the most common ones. Once you recognize these patterns, you will begin to see them in every schematic you see.


New website!

If you haven't visited our website in a while, you may notice that it looks much different. That's because we've re-designed it and switched from Google Checkout over to Stripe for handling credit cards and the like. It doesn't require your credit card to be attached to your Google account in order to use it, which should help some of our institutional customers. 

We've tried to duplicate as many links from the old website as made sense. Please poke around and see if we've missed anything important. 

Come see us at Maker Faire Bay Area 2013!

It's that time of year again -- time for Maker Faire Bay Area! We'll be sharing a booth with the Metrix Open Hardware Alliance, which is a coalition of several Seattle-area open source hardware companies, including OpenBeam USA, organized by our friends at Metrix Create:Space. We'll be in booth 514, in the southeast quadrant of the Expo Hall.

Academic Zigduino projects

A couple of interesting Zigduino projects in academic settings have recently been published. The first is from Frank Zhao, the author of the ZigduinoRadio package. He and his seminar group at the University of Waterloo created ARUCI: Augmented Reality Universal Controller and Identifier.

The second is a paper presented at IMECS 2013 about using Zigduinos andContiki to build loosely coupled wireless sensor networks. They are working with a middleware layer for building sensor networks called LooCI and evaluating how the Zigduino behaves with it.

New Zigduino r2 documentation and availability

First, the entire first spin of the Zigduino r2 sold out in two weeks. Since it's Chinese New Year, and our bare PCBs are made in China, it will be several weeks before we have more in stock. However, for those of you who do have them, we've got some amazing new documentation to show you. 

Arduino forum user pighixx has created gorgeous and detailed pinout diagrams for every official Arduino variant and a number of unofficial ones, including the Zigduino.

As you can see, it covers every pin and every function. I love these diagrams, and I am very glad pighixx was willing to create them for us! You can also download a PDF version.