In order for the Raspberry Pi to read the motor's position from the potentiometer, the analog signal needs to be converted to a digital signal. I selected an MCP3002 analog-to-digital converter (ADC) for this purpose. The digital output from the MCP3002 can be read using the SPI or I2C protocols and the Raspberry Pi has built in drivers in the WiringPi libraries for both protocols. I used SPI in the GE320 kit because the driver already existed in WiringPi, which made the implementation very easy.