1. low is high, high is low. if I switch the logic in code, all is well. it just bugs me.2. on program load, or board reset - all 8 relays "flutter" very fast. no harm, I guess. it stops. then code works as written. I do set pinmode on each pin, and do turn each pin off in setup. maybe adding a delay in setup? 3. I am testing on a DC power supply, not my main 12V (high amp) battery. I have noticed, that sometimes - and only sometimes - when the relay switches off - it flutters they system. I suspect this is low amp on my 5v side, not sure. I do have a high amp 5v source, just the testing DC supply is showing amp strain in this situation (when it flutters). I am controlling a solenoid with the relay (water valve) - and just have it straight hooked up to the relay. the relay just gives it the 12v. no other circuitry there.
1. low is high, high is low. if I switch the logic in code, all is well. it just bugs me. 2. on program load, or board reset - all 8 relays "flutter" very fast.
when I turn relay on - it does active the solenoid (valve opens). however, when the valve switches off, it flops, and its like the whole board does a reset.
I am using pin 13. should I ask why to avoid it..
Solenoids need a diode across the coil, to stop back-EMF spikes resetting your Arduino.Assuming the solenoids are (12volt) DC powered. Leo..