Hello everyone ! I am building an automated greenhouse with an Arduino Mega, but I have a problem with the 5V relay module (link in comment)I am using to control two pumps and a fan. I’m powering this whole system with a solar panel, have a VRLA AGM battery (12V/100Ah) connected to the solar controller (to power everything), and I use this solar controller (link in comment) to power the Arduino and the 12V stuff.
This is how the Arduino and the relay module are wired up.
This is how everything is connected to the solar controller.
The problem is that when I connect the Arduino to the USB port of the solar controller and the pumps and fan to the 12V, the whole system turns off and nothing is powered, not even the Arduino. But when I connect the Arduino to my computer (the pumps are still connected to the solar controller), everything works fine.
I know that it is better to power the relay module with a separate power source, for better isolation, but I can’t do that since it is really difficult for me to bring a 5V supply all the way to the greenhouse.
Maybe I’m just shorting everything with my wiring somehow, but I believe my wiring should be correct. It can’t be a common ground problem since the USB port of the solar controller and the 12V output share common ground.
Does anyone know what the problem is ? Thank you in advance !
