Does GPIO 1 have to connect to an EEPROM?

Q: “Is GPIO 1 functional for other purposes?”

Yes, it is. Most GPIO pins on the RPi are functional for other purposes. You can see this in the 3rd party pinout guide, for example.

Perusing the README file (/boot/overlays/README on your local filesystem, or in the GitHub repo) may give you additional insights into other uses for GPIO 1 available via overlays in the device tree. For example, on the RPi 4, GPIO 1 may be designated as the SCL for the i2c6 bus by using the dtoverlay=i2c6 overlay.

You may also choose to use GPIO 1 simply as digital input or output; GPIO = General Purpose Input Output.

In general however, it is likely safer to use GPIO pins in accordance with their default configuration unless there are reasons to deviate from that.

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