I purchased my kit Aug. 2019. Built fine. Works fine. Firmware is 2.8.1
I use solar divert from my emonPi. Usually works fine except it won't stay in ECO mode (a pain). Today it was stuck at 6 amps despite plenty of sunshine. Charge re-start fixed this. Web interface often needs refreshing. etc.
Considering a firmware upgrade. Looks like persistent ECO arrived with 2.9.0. That alone would be worth the freight.
Is all hardware compatible with all firmware? (eg: since Aug 2019 anyway?). Are there any hardware version codes I need to check?
I gather I need a programmer dongle?
Should I just go up to 5.0.1 or use some stable earlier version?
Is there a guide for upgrading with Linux? I can use windows if I have to but prefer not to.
Any other advice?