I’m looking for a way to extend the I/O on a 5v Pro Micro to add a 6x6 button matrix. I found the SX1509 I/O Expander Breakout but it’s 3.3v.
Is there another option to get the pins I need that is 5v? Or is there a way to connect the SX1509 to 5v without damaging it?
Unfortunately, the I2C pins are not 5V compliant. You will need to use a level shifter between the Arduino and the breakout. BOB-12009 or BOB-15439 should work.
/mike
I see, thank you. Is there an alternative 16 bit expander that is 5v?
A couple of [MCP23008’s daisy chained might work for you but double check the data sheet to be sure.](https://www.sparkfun.com/products/15099)