Re: i2c encoders in matrix with I/O #ubitx
Interesting devices. The boards also have 2 or 3 general I/O pins (depending on the usage of the LED), and 128 (256?) Bytes of EEPROM.
From a quick read of the Arduino library (https://github.com/Fattoresaimon/I2CEncoderV2.1) they have mapped registers at the selected I2C bus address (one for each encoder module). The registers perform configuration and access to encoder, push-button and GPIO pins and EEPROM data.
The library supports interrupts and callbacks which is handy but requires one interrupt enabled digital input pin (but I am not sure if it's one per module or if the modules can be daisy-chained to the one input).
73, John (VK2ETA)