But, if there's even a picoamp of leakage of 5V, anything above 3.63V, onto SCL/SDA, that breaches the RP2 spec.Except that if you know the details of your device, it's usually possible to run a 3V3 I2C bus with a 5V-powered device.
A genuine I2C interface will only ever drive the SCL/SDA signals to GND - the high level is set by the pull-up resistors.
I do however agree with you, that you can probably get away with it.
Statistics: Posted by hippy — Tue Aug 26, 2025 12:17 am