Hi,
I’m trying to work out if it’s possible to interface an IVT MPPT solar charger controller with homeassistant. There’s a serial link that’s used between the main controller and the remote display and I can connect to with a USB-TTL (CH340G) converter and I can manually poll it with Termite to get the information (Termite is like Hyperterminal but gives HEX output). I’ve managed this on Windows and can then manually decode the returned HEX string with Excel so I know I’m getting valid data.
The logic is; send an ‘R’ from the terminal; it then replies with 17 bits of information.
So far I’ve worked out that with a command line I can use the following to poll for the data:-
$echo R > /dev/ttyUSB0
Then if you’re running minicom in a second terminal/session, you can see that the R triggers the response from the charge controller as it returns information, but it’s just some D??O where the ?? is some random character(s), so not the HEX string I can easily work with.
I’d hoped that I’d be able to read the data in with the HA serial sensor integration, but that doesn’t seem to do anything and sits returning ‘Unknown’.
That said the overall interface with the unit might need to be more complicated so it periodically sends the R and then receives and decodes the string.
I’m assuming that other solar charge controllers may use similar interfacing so was wondering if anyone knows of any that are already doing something similar to this or if anyone’s managed to use the Serial interface to receive data.
Cheers, Matt