Eco-Eye Smartpv, Tasmota and serial connection

Hi All, first post here and very new to Home Assistant.
I need help please with an Eco-Eye SmartPv and getting data into HA.

https://www.eco-eye.com/product-monitor-solar-smartpv

I have HA running on a Raspberry Pi 3. I have a solar pv system and use an Eco-Eye Smartpv to display power usage and generation.
This device has a serial connection on it and every four seconds it sends two lots of data (uuuu,gggg) terminated by a carriage return, where uuuu is usage in amps * 100 and gggg is generated in amps * 100. I have it connected to a Wemos D1 Mini running Tasmota.

When looking in the Tasmota console I can see it publishing the values to my mqtt topic. For instance -:

12:49:32 MQT: tele/testmqtt/RESULT = {“SSerialReceived”:0103,0609}

I have set up a sensor in Home Assistant called smartpv.

sensor 7:
   platform: mqtt
   name: smartpv
   state_topic: tele/testmqtt/RESULT

When I look in Developer Tools, States it shows the following under sensor.smartpv

{“SSerialReceived”:0079,0611 }

so the sensor is showing data.

Now I’m stuck as I don’t know how to extract that data in HA.
I would like to split out the data perhaps into two sensors? one called usage and one called generated. I would then like combine them into a Lovelace card (perhaps a guage?) to show red when using energy and green when producing more than using.

I have spent a few days searching for a solution but nothing seems to come close.
Is it a json payload? and I suspect I need to use a template but as a new user I now need some help if possible.