Hello,
I have the pim470 screen, I configured my boot config by adding
dtoverlay=vc4-kms-dpi-hyperpixel4sq
Work great. Issue arises when I try to use I2c from the screen connector. If I connect this to an I2C device, the touchscreen partially works, meaning only the side of the screen recieves touch, and I cannot figure out how to get a readout from whatever I2C bus the screen is trying to use. I cant see i2c-3. I’m aware of this info: Getting Started with HyperPixel 4.0 but it is limited. Do i have to enable i2c in interfaces? If i do the screen no longer works.
Appreciate any assistance.
The screen uses i2c-3 and also sets it up. If you add a device and this interferes with the touch-driver, this is a hint that your device does not behave well. One reason could be that it adds additional pullups (many i2c devices have these builtin pullups). But this is only speculating and one possible source of problems. Wrong wiring is another.
Secondly, most i2c drivers are hardwired to ic2-1 on the Pi. Check the driver of your device and try to reconfigure it to use i2c-3.
i appreciate the response. Is there a way to tell that i2c-3 is enabled on the pi and functional? I’m confused because without any devices attached to i2c, and the screen fully functional with touch, I get this: pi@cinepi:~ $ ls /dev/i2c-* /dev/i2c-11 /dev/i2c-12 /dev/i2c-13 /dev/i2c-4
Hm, this is strange and maybe something changed. You can do the following:
dmesg | grep -i goodix
Goodix is the chip of the touch-driver and the above command will search for related messages during system startup. Taken from Hyperpixel 4 rectangular, touch not working · Issue #176 · pimoroni/hyperpixel4 · GitHub. Seems like it is now ic2-11. You can also install i2ctools and use i2cdetect, in this case i2cdetect -y 11