Marstek Venus E 3.0 Support via OpenAPI (generic)

[romeoro]

Evcc should support the Marstek Venus E 3.0 (and other Marstek devices) via the OpenAPI interface to enable an easy and smooth integration into evcc.

[StefanSchoof]

If it is a simple http API, you should be able to use the the http plugin. If this is working this can wraped into a template so others can use it easily.

https://docs.evcc.io/en/docs/devices/meters#custom
https://docs.evcc.io/en/docs/devices/plugins#http

[romeoro]

Sadly it's not a simple http api. See @OptiMael answer
#26026 (comment)
with the api spec:
https://static-eu.marstekenergy.com/ems/resource/agreement/MarstekDeviceOpenApi.pdf

[OptiMael]

I think it's this API specification:
https://static-eu.marstekenergy.com/ems/resource/agreement/MarstekDeviceOpenApi.pdf

I hope to find some time in the next weeks so I can have a look at it.
My neighbour just got his "Venus E 3.0" which makes it a goot testing candidate.

[romeoro]

Happy to support with testing as well, sadly it's not a "simple http api" as it seems to be UDP based.

Using packetsender (https://packetsender.com/) i can query the API at least for device discovery
UDP broadcast to local network broadcast address of:

{
"id": 0,
"method": "Marstek.GetDevice"
,
"params": {
"ble_mac":"0"
}
}

results in a proper response.

{\n\t"id":\t0,\n\t"src":\t"VenusE 3.0-***",\n\t"result":\t{\n\t\t"device":\t"VenusE 3.0",\n\t\t"ver":\t145,\n\t\t"ble_mac":\t"***",\n\t\t"wifi_mac":\t"***",\n\t\t"wifi_name":\t"***",\n\t\t"ip":\t"192.168.188.207"\n\t}\n}

Sadly the get battery request to the according IP already results in no response.

{
"id": 1,
"method": "Bat.GetStatus"
"params": {
"id": 0
,
}
}

[lemuba]

Does this makes sense currently as the Marstek API is not stable at all? https://github.com/jaapp/ha-marstek-local-api/issues