A while ago I started work on a Raspberry Pi controlled LED Chaser project, designed to look just like the lights on the front of KITT (the car from Knight Rider).
It started off with a few LEDs and an Adafruit Cobbler breakout kit for easy hookup to the GPIO pins on the Pi.
The Raspberry Pi has a limited number of IO pins but it does have I2C and SPI. So I used a MCP23017 I2C expander chip to increase the IO pins to 16 which will allow me to drive 16 LEDs in all.
Here’s how it started:
And to make sure it was working in theory:
Taking shape now, all sixteen LEDs in place:
And making sure all sixteen work smoothly together:
Once I was happy that it all worked as planned, I decided to transfer it to a more permanent board.
Then to add the LEDs:
A quick test:
And we’re all done:
Any questions, just ask 🙂