question

I reckon you can, I would give it a try.

There might be an issue with drivers depending how the Venus OS software deals with the RS485 being on the waveshare shield and not on a USB > RS485.

But I would not have thought you cant do any damage by try it. Worst case it just will not show up!

It just does not show up. However, as the RS485 on the Hat ist just using the UART on Pin 8 and 10 of the Expansion Port it definitively has a device name in Linux and by modifying the serial-starter.rules in /etc/udev/rules.d it should be possible to trigger the RS-485 task for it. I did not try it, because I found a USB to RS-485 Adapter in my toolbox with the required FT232R chip and that did work out of the box, however I will give it a try with the RS485 on the Hat has this would be very convenient and save one of the spare USB ports.

Just found out, you probably cannot, the serial interface on the GPIO has been reused for the bluetooth since Rapsberry PI 3 and the serial interface on the GPIO is no longer a hardware UART. So it is not worth to try it as most likely Venus OS does not provide this driver. In any case, I have a working setup and most likely will have to use a USB-Hub with enough ports.

Hi

can you tell me which USB to RS-485 do you use to operate "out of box"

I want to read out my smart meter via HAGER EHZ001K to the Venus OS, to build up an ESS

is this possible`?

thank you

Actually, you can deactivate the bluetooth to enable UART connection, on AMA0 port (config.txt). You’ll have to disable the console as well (command.txt).

I did that with success without the HAT in order to read periodically data from my meter via OBIS / optical interface. But with the HAT plugged I couldn’t manage to use this port, via HAT extension pins.

Ich hatte anfangs das gleiche Problem da ich mir das
Waveshare Isolated RS485 CAN HAT (B) geholt habe welches 2 RS485 und ein CAN Bus hat. Beim rpi4 musst du wie oben erwähnt das bluetooth ausschalten. Und eine udev Regel erstellen dann ging der Controller bei mir ohne Probleme.

ergänzungen in der /u-boot/config.txt

>

dtoverlay=disable-bt

dtparam=spi=on

dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=25,,spimaxfrequency=1000000

dtoverlay=sc16is752-spi1,int_pin=24

>

folgende Datei erstellt /etc/udev/rules.d/gpio.rules

>

ACTION=="add", SUBSYSTEM=="tty", SUBSYSTEMS=="platform|usb-serial", SYMLINK+="serial-starter/%k"

ACTION=="add", SUBSYSTEM=="tty", KERNEL=="ttySC0", ENV{VE_PRODUCT}="6001", ENV{VE_SERVICE}="rs485:default"

ACTION=="add", SUBSYSTEM=="tty", KERNEL=="ttySC1", ENV{VE_PRODUCT}="6001", ENV{VE_SERVICE}="rs485:default"

>

reboot

Wie bekommst Du denn dann das Modbus RS485 Gerät in Venus OS hinzugefügt? Da scheitere ich aktuell