Is it possible to control a board to add relays to the Cerbo via USB? Or is it another way to have more relays in the Cerbo?
Thanks!
asked
Cerbo GX and USB relay board
you could control (on/off) an external relay board via one of the internal relays of the Cerbo GX as long as you stay within the specs for the internal relays (DC up to 30VDC: 6A).
To control the external relays, you would need a 3rd party application or control board.
Thanks! How would it work? I’ve been looking around but can’t find nothing :(
What are you looking for?
FWIW. this is not supported by Victron. And I've never heard that someone has been using a USB relay board I think.
For that to get working, you'll need coding experience and develop a driver for dbus so that you can control it like the internal relay from the GUI. But I'm not 100% convinced that the Cerbo can power such a relay board from its USB ports. Maybe @Kevin Windrem knows more?
The workaround could be as explained in my other post above.
I'm also looking for a simple solution to add few external relays to the Cerbo GX, without requiring to rely on aIP network (it would then require I let the network switch powered up 24/7).
So I was thinking about few alternatives:
1/ USB Relay board (external powered with 12v): https://flows.nodered.org/node/node-red-contrib-usb-hid-relay The issue is that HID driver doesn't exist for VENUS OS, and not sure how we can tweak the linux OS so we get the correct USB libraries installed...
May be will be more lucky with a CH340 based USB relay board, don't know if it will be correctly handled by Venus OS?
2/ Bluetooth Relay board: not sure if any node-red drivers exists at all....
May be Victron would realise there is a market and propose their own relay board, attached to a CAN bus ?
Any other ideas?
Hi, use an ethernet connected MQTT controlled relay board. Available on Aliexpress.
Well, since, I made some progress.
I have selected DTWONDER IO box (8x Digital IN + 8 Relays) that I can control over Modbus TCP or Serial.
So far I managed to get it working perfectly in TCP, and fully integrated with Venus OS GUI, so I can see and control 4x additional Relays from the GUI. for the remaining DI and relays, I'm using them through Red-Node.
So far, so good.
I'm now trying to switch to Modbus over RS485. The USB interface I have is CH340 chipset based, and at this stage, Venus OS is trying to figure out if this is either a GPS or a battery BMS attached to it.
I will probably have to do some tweaks so I can use the USB interface from Node-Red.
Any hints?
cheers.
Hi Fguiot, I have tried to do the RS485 as per your solution above without getting it working. I cannot get any any serial communications back from the DTwonder, I have a 4ch and 8ch both with RS485. I have given up on this path but am very interested in the TCP you mentions. Is there any information you can share on the TCP approach?
