I had four DC Micromotor 141:1 gearbox w/ encoder motors hanging around and wanted to make a robotic arm with them to play with various code. I also enjoy doing motor control stuff so I decided to make my own distributed motor controller as well. Here is the latest video of the arm in action moving between two points. There is some stiction from plastic rubbing on plastic.

I designed the arm using solidworks, printed the parts for it on a Makerbot Replicator 2, created the controller boards in eagle and had them fab'd by OSHPark (hence... purple silkscreen). There are four wires going from board to board, two for power and two for i2c. The whole motor controller fits into 32KB of flash onboard the STM32F0 micro, I have a host machine giving end position goals and the micro does the trapezoidal profile and PID at 1KHz.

I have forward (fk) and inverse kinematics (ik) working. The ik was done using ikfast all I did was generate the urdf file and it generated the code. I'm in the process of generating the path planning code.