We love the little SN3218A chip we used to make PiGlow so much that we've decided to turn it into a handy little breakout module.

This is a super low-cost way to drive 18 LEDs at constant current up to 34mA per channel. Simply hook up the cathode of your LEDs to the channel and provide a common 5V supply for the anodes and away you go!

• 2.75 - 5.5V supply and logic voltage
• Up to 34mA per channel constant current sinking (adjustable)
• Bread-board compatible format
• I2C interface (address 0x54)
• Supplied with 0.1" headers to solder yourself

The I2C interface is very simple to use and works with Raspberry Pi, Arduino, and most other platforms - the device address is 0x54. With the Raspberry Pi you can use the 3V3 supply to power the chip (via the VCC pin on the breakout board) and the 5V supply to power the LEDs.

We have an Arduino library available here: https://github.com/pimoroni/pimoroni_arduino_sn3218

And a Python one for the Raspberry Pi, too: https://github.com/pimoroni/sn3218