Home Assistant OS

[jayNorth]

Hi,
I've installed the latest Home Assistant OS in my RevPi Connect 5 (Item #100414).
This model has build-it RS485 and CANbus.

HA Core 2026.5.1
HA OS 17.3
Linux 6.12.75-haos-raspi

It all works fine except RS485. The device is not showing up in the /dev folder. CANbus and other IO is not tested, as only RS485 is currently of interest.
Enabling SPI in /boot/config.txt resulting in ttyAMA0 showing up, but I suspect this is the piBridge interface.
I'm not sure if there are spesific dtparameters that could get this working.
The schematics shows that uart2 is the like suspect. Not yet sure how to test this.

Has anybody else had luck getting RS485 working in a custom OS?

-Jay

[tboehler]

Hi Jay,

I suspect that the Device Tree Blob for your RevPi Connect 5 is missing on HomeAssistant OS.

You can generate these with our Linux Kernel Sources:

Code: Select all

git clone https://gitlab.com/revolutionpi/linux.git
cd linux
make -j$(nproc) ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- dtbs

Or you can copy them from a working RevPi running our image from /boot/firmware/overlays, depending on which DTBO you need:

Code: Select all

$ ls /boot/firmware/overlays/revpi-connect5*.dtbo
/boot/firmware/overlays/revpi-connect5-can-can.dtbo
/boot/firmware/overlays/revpi-connect5-can.dtbo
/boot/firmware/overlays/revpi-connect5.dtbo

You also need to tell the Raspberry Pi bootloader to load this DTBO by adding "dtoverlay=<overlay-name>" to the /boot/config.txt on HomeAssistant OS.

Good luck!