asd has written an article on interfacing Adafruit 7-segment Backpack with Bus Pirate
Bus pirate doesn’t do much by itself but needs some accompanying chip talk to. I got my hands on 7-segment display from Adafruit which has HT16K33 controller on it. HT16K33 chip is accessed via i2c protocol so it is good candidate to learn about i2c.
In this blog post I briefly show how to display “1 2 3 4” on this display using bus pirate.
Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.
And if you can do it with an Adafruit backpack, you can do it with a hacked $3 voltmeter a la Baoshi.