Is it possible to use the expansion header I2C pins as GPIO. Really just input. I have an optically isolated pulled high 3v3 and low active switch I want to use.
Those pins are used for the touch controller. Even if you have a Hyperpixel without touch, I don’t think using the pins for GPIO is supported in the Hyperpixel library.
What you could do is attach something like an Adafruit Seesaw, and use that to read the switch over I2C.
EDIT: Looks like I have it all wrong, ops.
I would “think” that is doable? Their default function is i2c 0 for reading the Hat EEPROM to get setup info etc for the attached HAT.
GPIO 0, Pin 27, EEPROM Data
GPIO 1, Pin 28, EEPROM Clock
Pimoroni just redirect i2c to use i2c 0 instead of i2c 1.
You may have to undo that and or make sure i2c is turned off. You won’t know until you try using one of those pins.
The Hyperpixel guide says that the I2C expansion pins on the screen unit are BCM 10 and 11, I don’t think those are the EEPROM pins.
I don’t think the I2C pins on Hyperpixel are the standard I2C pins, I think they’ve had to shuffle them around seeing as HP4 uses so many pins for different things. The touch controller is apparently I2C controlled, so using those pins makes sense.
@Shoe, I think I got it wrong, what you posted sounds a lot more plausible.