Frank over at RaspberryAlphaOmega writes:
After thinking about how to drive the MAX7219 LED array I built yesterday, it occurred to me that maybe this is an ideal time to get to the bottom of how to use the Bus Pirate board that I failed to use with a MCP3002 ADC chip. This time I was determined to get it working.
Get an assembled Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.