Skip to main content

Posts

Showing posts from January, 2016

Growatt inverter monitoring with Raspberry Pi

At home we have a small (2.5KW - 10*250w panels) PV system to try and offset our daytime electricity usage. This is connected to a 'Growatt' inverter that handily has both RS485 (wierd 2 pin plugs) and RS232 (9 pin D connector buried under a screwplate) outputs.

With the firmware on ours (installed Sept 2013) it supports modbus-rtu over serial 9600 8N1.

I had done some initial digging and experimentation (as announced on Whirlpool) but never really got sensible values out.When my guruplug (via a long USB to serial adaptor) finally died and I shelved the whole thing. With the completion of the structured wiring though I finally got round to reconnecting it and starting again.

Small D9 Gender changer, + cisco console cable (all hail fleabay) gives a nice neat look on the outside, and in the garage I have another console cable plugged into the relevant patch outlet and a cheap usb-serial adaptor in a Raspberry Pi (which also has a GPS module connected, acting as a PPS NTP master)