Monitoring of a solar installation with 24V 330W panel, Tracer4210AN MPPT controller, 12V 138Ah battery and 12V 1000W inverter. Used STM32F103 to decode controller data and get inverter current and SIM808 GPRS module to communicate with ThingSpeak
Single 250w solar panel connected to 350w grid tie inverter. Measuring done with Arduino Mega 2650 and Ethernet Shield to directly connect to ThingSpeak. sampled 100 times per second and then averaged for per second monitoring but 30 sec update to here.