Is it possible to disable the standard SDA and SCL (A4 and A5) pullup resistors on the Nano 33 IoT? I have been having difficulty keeping a stable communication between two Nano 33 IoT closely located. Seems to work for a moment then stops. I am wondering if this might work:
pinMode(pin, INPUT)
Have a look at the schematic of the board (right side just under the Crypto chip symbol). You can find it in the store under documentation. Here is the same link.
The two pull-up resistors are hardwired to 3.3V. So, you cannot disable them by software. You could remove them with a soldering iron.
Note: I2C does not work without pull-up resistors.
Thanks for confirming what I thought I saw also in the schematic. I'm thinking I could use a second I2C port on different pins then use my own pullup resistors. Or maybe add additionAL PU resistors. I'll keep trying.........