Program uses a LPC1768 processor for controlling a robotic arm. The basis for the program is the Axis () class which uses a PID controller to actuate a DC motor with quadrature encoder feedback. The LS7366 encoder interface IC off-loads the critical time and counting requirements from the processor using an SPI bus interface for the class. The Axis class then uses a state machine to perform trapezoidal movement profiles with a Ticker class. Parameters can be adjusted through the serial interface using a FT232RL or similar USB to serial interface IC for computer communication

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Above is the prototype for the controller. A PCF8574 I/O expander is used to read the limit switches by the I2C bus. Six motor driver breakout boards using the MC33926 motor driver chip were used to drive the motors.

/media/uploads/jebradshaw/100_2490.mp4 Short homing and calibration demo.

I use the mbed online compiler to generate the .bin file, use bin2hex to convert it and upload the hex file to the processor using the serial bootloader with an FT232RL usb to serial converter. I've started putting this on a PCB and hope to finish by the end of the month (Dec 2015).

Joe B