So I am using a Uno connected with a GSM shield and a relay shield. I am using the gsm shield to turn on a relay on the relay shield. When I have it hooked up to my computer via usb cable it woks great and when I say turn on the relay turns on and stays on until I unplug the board or tell it to turn off.
Sadly when I connect it to a 12volt power supply instead of the usb cable it doesn't work so well. It will turn on and run but after a few minutes or a few hours something happens and the relay turns off. Why? I thought that it might be a power issue since I was only using a 840 mAmp power supply. With that I bought a 2 amp power supply. I still have the same problem! I even tried to supply the Uno and the GSM shield from different power supplies and I still have the problem. What is happening? Does anyone know?
Thanks in advance