Hi,
We (the community) are discussing how to support Victron in the diyBMS (https://github.com/stuartpittaway/diyBMSv4ESP32). Can you please answer few questions :
/peter
Hello all of you! ;o).
That sounds like a cool plan.
1. Protocol: I recommend to use the CAN-BMS protocol. Because that way you don't have to do anything on the Venus OS side; which (a) saves you an enormous amount of work, and (b) your solution will then work with out of the box Venus OS, instead of having to install something special and/or having to wait for us including a new driver into the default images.
2. I can share to to you by email Peter, but first: is CAN an option for this project? You'll need to do something in hardware to have CAN on the ESP32 I'd expect?
3. rPi and Venus OS: you mean a RaspberryPi and a Cerbo GX? I'd test it with a Cerbo GX only. No need to test it with anything else.
Matthijs
I am trying to develop a device that converts RS485 to CAN.
Could I also get the CAN-BMS protocol?
Thank you
Is it possible to get the CAN-BMS protocol as I have a battery that speaks a CAN protocol that my Cerbo does not understand. For this reason I want to build a "translator".
My driver could also work for you if you do not have a CAN hardware interface.
You will need a USB->UART cable and connect that to the UART on the ESP32. The driver use the serial interface to poll for BMS data and publish that to VictronOS on the dbus. A direct UART->UART should also be possible but a bit more work.
You can test with your BMS and VenusOS running on a Pi3+. No need to have an inverter for the test. You can look at your results in the RemoteConsole, dbus-spy or VRM.
https://github.com/Louisvdw/dbus-serialbattery
Edit: I see you mention RS485. That would be a great option if you plan to have multiple batteries connected. Each BMS a slave on the RS485 line.
That might be an even better idea, yes.
Note @peternielsen, that once you're going for "closed loop control", ie. the BMS sending dynamic CVL / CCL / DCL values, you will need a full system, including Inverter/charger & solar charger to test. But after quick read through @Louis van der Walt his material (nice!) I think thats not part of this at the moment. And btw also not necessary, systems can work very well with static values, as long as they are configured properly ofcourse.
Every thing bus based should use CAN , that’s what I’m doing , for lower level solutions I use I2C or LIN bus. Forget RS485, way to proprietary
What is CAN-BMS. Where is the protocol documented ?
