RP2040 Nano Connect crash - No Pullup on SDA & SCL

After running a varying number of hours my RP2040 Nano Connect will crash. Pushing the white reset does not bring the Connect back to life. The USB/serial port says there is no pullup resistor on SDA and SCL. The pullups are built in to the Connect. I have added external 5.1k resistors to see if that will help. Ctrl-D keeps complaining of no pullups. Only removing power restores operation. The SDA/SCL bus is only driving one SSD1306 OLED display. What is happening, what can I do to fix it?


Does it continue if you disconnect the display?

It is not a reset button, it is a bootloader button. You should hold it down when you power up the device. It then makes it ready to relieve new code.

Reset is done in the time honoured way of removing and then re applying the power.

There are several sets of pins that can be used for the I2C bus are you using the same set as the pull up resistors are connected to?


FYI - I love your name.

In the RP2040 Nano Connect the single white button is the reset button not the boot button.
To get to the boot function the user must connect the QSPI_CSn pin to its neighbor GND pin.
Arduino built in a firmware function into their code that if you push the reset pin twice quickly you will get into the boot function. If you are using CircuitPython that code has not been incorporated so a real boot button between QSPI_CSn and ground is required.

The pins I am using are the ones defined in the CircuitPython documentation and the RP2040 Nano Connect schematic. I get the same issue with or without my additional 5.1k pullup resistor.


No it does not continue with the display disconnected.

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