Small Stepper Robot Arm Shuffling Sugar Cubes 

In this video I show what this little Arduino/Raspberry Pi powered stepper robot arm with record and play functionality is capable to do.
Here's a blog post about this project:
electrondust.c...
A really quick summary on how it works:
The Gripper uses a servo which is controlled by the Raspberry Pi.
This robot arm uses 4 cheap geared stepping motors.
The motors are powered by 4 A4988 drivers.
The drivers are controlled by an Arduino Mega running a modified version of "grbl":
github.com/dgu...
The Arduino waits for movement commands coming in via serial port.
The movement comments are being sent from a Raspberry Pi.
The replica arm which is used to control the pose of the arm is mode of 4 potentiometers.
The potentiometers are connected to a MCP3006 (this is a A/D converter chip). The chip is connected to the Raspberry pi via SPI.
The Raspberry Pi reads all the potentiometer values and sends position commands to the Arduino.
Here's the complete code for the Raspberry Pi:
github.com/T-K...