Boarduino by LadyAda / Adafruit.
My first Arduino-compatible board. It’s the clone of the old Arduino Diecimila (with an ATmega 168P), in a breadboard-friendly format. It’s ideal to start with hardware computing and the breadboard format helps interfacing it with sensors and other circuits.
Sanguino by Zach “Hoeken” Smith
I needed more memory and pins than the usual 168P, so I started using the 644P in the Sanguino, and made it a basis for most of my projects. It has been my main devboard for quite some time, before I made the Mobius Modular board.
Teensy 2.0 by Paul Stoffregen
Graciously donated by Paul for the purpose of developing the MIDI library on the Teensy, I’ve been using it mainly for this purpose. It has the same chip as the Arduino Leonardo, meaning it has native USB HID support.
Teensy 3.0 by Paul Stoffregen
One of my last acquisitions. ARM M4-powered, this little board can be one of the next big things in the ARM devboard race. I don’t think it might be powerful enough to run an OS “comfortably” like the Rasberry Pi, but a small RTOS should not be a problem.Detailed review here.
I currently use it as a unit test platform for the MIDI Library. The native USB driver in the ATmega32U4 makes it a good board to experiment with native MIDI USB, to create plug and play MIDI controllers and synths.
Mobius Modular Motherboard
I made this board to simplify the prototyping of MIDI devices and to be the heart and mind of my Mobius project. It’s using an ATmega 644P and features an IO expander for an LCD screen, as well as a hardware switch debouncer. The central connector breaks out access to 10 GPIO pins.
I feel a bit guilty of using it only as a Git/Web home server, but it’s doing the job quite well. It’s running the Wheezy distro without many modifications. I might give a try to the Adafruit Occidentalis distro to play with the GPIO.
Texas Instruments Stellaris LaunchPad
The cheapest ARM board I’ve ever seen ($4.99 including worldwide shipping), but comes with limitations, as it’s only a demo board. Still, for that price, you get two ARM M4 chips.
Open Workbench Logic Sniffer by Dangerous Prototypes
Logic Sniffers are useful when debugging digital circuits, but also for firmware debugging: toggle pins when you enter and leave a function to check how much time you spent inside it! It can also analyse most serial transmissions (when setup correctly, took me some time to get it right).
Bus Pirate by Dangerous Prototypes
Very useful little tool to control almost everything that talks a serial language. Scriptable in Python, so with PySide you can make nice interfaces to analyse, control and hack the world. Note: If you plan to use it as an AVR programmer, prefer an USBtiny or something similar, it’s damn too slow.