I want to build a cable tester, which will have a dozen connectors, each with 15-80 pins. The software will check to see which pin pairs are connected, pair by pair.
Which i/o port expander is better (simpler) for this purpose? I2C, SPI, or serial?
It would simplify programming if each connector had its own expander, but I don't find any that have 80+ pins.
For example, the finished device would check if pin 9 on connector 1 is connected to pin 9 on connector 2, and so on. Speed is not an issue.