HyperPixel4 affects PiJuice battery HAT and RaspiAudio Mic+ HAT


#1

Hello,

I’ve just purchased two HyperPixel4 touch screen, very nice screen, thank you.

Using Raspberry Pi 3 B+ with Stretch Desktop and camera module enabled.

I am experiencing issues with two different HAT units with I2C bus when using this HyperPixel4 touch screen.

1.) PiJuice battery supply HAT
2.) RaspiAudio Mic+ HAT

When the HyperPixel4 is top of PiJuice HAT appears to still work, however the PiJuice-Gui software no longer works and no ability to manage power settings.

When the HyperPixel4 is top of RaspiAudio Mic+ HAT, the HyperPixel4 works, however the RaspiAudio Mic+ no longer works. It states the sound card is not available in the device. Alsamixer no longer works, etc. Will consider different microphone HAT unit that can have the mic wired/extended to the case, preferably not USB mic unless this is the only mic option.

The HAT devices complains that the I2C bus is no longer available. Although the I2C preferences is enabled.

I have not tried all three together as one unit whereas the HyperPixel4 is top of RaspiAudio Mic+ HAT and this is top of PiJuice HAT to the Raspberry Pi board. This is the setup that I want to use with the camera module enabled.

Here is PiJuice url link https://uk.pi-supply.com/products/pijuice-standard

Here is RaspiAudio url link https://www.raspiaudio.com/raspiaudio-aiy/

If possible, please advise knowledge workaround or resolution fix, much appreciated if this can be solved.

Thank you,
Bob512


#2

HyperPixel does not use BCM2 and BCM3 as an i2c bus- they are the V-Sync and H-Sync signals for DPI respectively. See here: https://pinout.xyz/pinout/hyperpixel4

If you want to share an i2c bus with HyperPixel you must reroute your device to BCM10 and BCM11 which is the bus used by the HyperPixel touch controlled, visible on the system as /dev/i2c-3