thanx for replies, really appreciate info, especially for a nub to arduino.
next question you guys made me think of saying it is possible.
I want to retain settings from being powered up initially, sleep, woke up …
if I power_down, will it retain settings??? or should I use standby?
the circuit is running off my secondary battery bank so not really crucial for draining but don’t want to have low cells every morning to charge back up. I have default setting of 90 deg F but will most likely be adjusting so if I ‘power down’ the 328p, I want to retain the set point instead of having to reset each time it wakes. being power down is most saving, that would be great to use.
ok, I have one more question, I lied.
I also have three separate pcb’s. 2 have 5v reg’s and third is just lcd and buttons ribboned from main board.
being I am using the same 12v (14.5V) from battery string do I need to loop the boards together with the power feeds?
power in to main board and out from main board to next, or being same power will the ground (negative) be same with separate board power feeds.
I have a main power rail in the back with power line to radio up front. im thinking the return bar will carry over from one board to next without having to loop power feeds. I have attached a sketchy sketch of existing power supply I ‘think’ (help us all) should work.
I don’t hold myself responsible if there should be more dimly light bulbs going off for further question… TIA