Beginners • Re: More I/O for RPi?

As you've found, a HAT normally covers all the PINS but may not use them all. After you've identified that there are pins you can use, without conflicting with the HAT, is to get a PIO extender like this to expose all the pins on a separate block https://www.amazon.ca/GeeekPi-Connector ... 840&sr=8-3

The Hyperpixel4 touch uses ALL the pins, not just covers them.The non touch version should have a few free where the touch bits would be connected https://pinout.xyz/pinout/hyperpixel4
There is also an extra I2C available https://forums.pimoroni.com/t/using-the ... -4-0/25425
I haven't tried any of this as I don't have one.

I've a HyperPixel 4 square. That has the bit banged I2C bus available via a header on the board though I'm not sure if the interrupt pin on that header is connected to a GPIO.

From what I've read there are a couple of GPIO available on the camera connector on 4B and earlier that can be used for interrupt lines if you're not using the camera. Sorry, but I don't have the links to hands. Not sure if that's possible on the Pi5 given the dual nature of the connector (CSI/DSI).

As said, might not be that easy to use the CSI/DSI connector.
Have no idea how it is implemented on Pi5; CM5IO shows 2 GPIO on the connector J5 which carries CSI/DSI0.I don't know the spec of the hyperipixenl, nor do I own one. My feedback is base on device tree overlay data. The touch seems to use GPIO27 as interrupt. Sorry, but I've never bothered how this display will get initialized in in which sequence the resources get claimed/released.

Statistics: Posted by aBUGSworstnightmare — Wed Oct 29, 2025 2:52 pm

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