I2C SDA cannot be on GPIO46

[skot]

According to the Espressif Boot Mode Selection doc, GPIO46 being pulled high breaks the serial bootloader.

GPIO46 must also be either left unconnected/floating, or driven Low, in order to enter the serial bootloader.
In normal boot mode (GPIO0 high), GPIO46 is ignored.

Pick another pin for SDA. All GPIO pins can be used for I2C on the ESP32-S3

[skot]

The solution for these boards is to cut on the green line and then airwire from R19 over to pin 15 on the ESP32 (pink line)

Just need to remember that SDA on the debug header won't work anymore.

[skot]

Using GPIO3 for SDA is not the best idea either. according to the ESP32 HW Design Guide, GPIO3 is also a strapping pin that controls the JTAG source. I need to investigate how GPIO3 strapping should be used in this case.

[skot]

Actually... The ESP32 has configurable internal pull-ups that can be used for the I2C pins. I think this means we don't need the external I2C pull-up resistors R18 and R19 at all. This means pin-16/GPIO46 can be used for SDA after all.

[skot]

this was fixed in 747d241