OpenSprinkler › Forums › Hardware Questions › OpenSprinkler › Powering from car battery. › Reply To: Powering from car battery.
August 27, 2020 at 1:42 pm #68056
I do NOT recommend using the battery unless if you can make sure it has regulated output voltage at 12V or below.
You can use a 7805 linear regulator, a switching regulator like this:
or a simpler solution is to use a bunch of diodes in series as a way to drop some voltages. Please make sure that the input voltage MUST be provided through the black power barrel, NEVER provide input voltage through the pin named VIN — the VIN pin is a 5V output pin for powering certain sensors, it’s not for input power.