I’ve spent the past few days trying researching communication protocols and I have a few issues. With sewable electronics, you need to work with cables with a fairly high resistance that are constantly moving. That means unreliable and noisy communication. Furthermore relying on multiple data lanes increases the needed number of stitches and the chances of failure.
Adafruit Neopixels use a good system that allows them to only use 1 data pin for a large number of individually controlled addressed devices with a total of 3 connections between each device. Disconnecting the devices while in use doesn’t cause them to crash most of the time, and there’s a lot of expandability. Best of all, the circuit design is incredibly simple because most of the hardware is on board the IC. The problem is that the communication type they use seems to be specifically designed for use on those circuits only, and to my knowledge there is no version of the logic circuit that isn’t coupled with the SMD RGB LED component, and even if there was there’s no way to directly adapt it to other components.
I’ve looked into I2C, SPI, UART, FTDI, USB, CAN-bus, and a bit of DMX and I’m still fairly certain none would work. All I need is to exchange bytes of data between two microcontrollers without them constantly crashing. I’m willing to try the most exotic solutions imaginable.