well I have a water timer already.
l am look at getting a Multimeter as I can test the wires.
Right now I looking for the parts I will need.
What a relay ? would that be the rain sensor module ?
For the timing patterns I was thinking of using the water timer's own circuit board, as it has already got the timer built in.
Does the Arduino have a timer built in ? or will I need a timer module ?
Would the solar module cover the overcharge protection board ? E.g. solar parcel is making power but the batteries a full changed so it stops sending power, utill the battery have drop in power.
My last question so far, can Arduino control the water timer's circuit board or can Arduino only control parts made for Arduino ?