Review on 🧩 Waveshare MCP23017 IO Expansion Board - Expand 2 Signal Pins as 16 I/O Pins, Compatible with 3.3V and 5V Levels, I2C Interface by Gary Zielinski

I needed many I/O ports for my Raspberry. I bought a total of seven of these. This board was very easy to use both for setting up the I/O ports. Interrupts are a nice feature, as is the ability to programmatically pull the input port high. No fuss Ruby examples. Pros: * Ease of use for I/O expansion. * Nice features (I/O configuration, pullups, interrupts) * Great code sample (C and Python). Cons: * Difficult to assemble as there is only one set of holes in the panel (ideally there would be a hole in each corner). * Soldering address bridges (A0/1/2) is also a small job