For networks week, I was attempting to get a PCB with an RP2040 to communicate with a PCB with an ESP32S3 using I2C

You can read more about the test I was attempting to run in my final project page, but essentially the goal was to have one capactivie touch pad control one neopixel strip.

Based on my understanding of I2C with the Xiaos, after making these two test PCBs, I needed to connect them together using their SDA (Serial Data) and SCL (Serial Clock) pins. For both microcontrollers, those pins should be D4 and D5.

I used jumper wires to connect the SCL to SCL and SDA to SDA and attempted to pass a basic message between the boards when powered. Here I ran into an issue that may be Mac related but it became impossible for my computer to recognize the microcontrollers. Despite changing ports and unplugging and replugging and reseting the controllers, I could not get my Mac to recognize that they were there.

After an hour of troubleshooting I attempted a different method of trying to get the two boards to interface through python using my computer as the interface to send messages between the two. After talking to a few classmates, I realized that this was not the right answer.

An update from the future with some insight from Anthony - I believe a possible source of the error is in the pins that I connected. He re-explained I2C to me and informed me that I actually should have been connecting TX and RX between the boards. With TX from one going into RX on the other and vice versa. For the final project I was able to reduce scope to only one single board, but next time I am trying to communicate between, I will try with these pins instead!