Thx again to fungus for the help with 2 NANO, 1 switch.
(ref. 2 Arduino controller boards - 1 shared input - General Electronics - Arduino Forum)
Now that I can share an input between two Arduino boards I am wondering how to share an output.
My goal is to use 2 Arduino Nano to control the same relay.
Here I'm re-wiring the output of two voltage regulators together (which is bad!). (quote fungus)
Is there a better way than this?
thx
You will need a VERY small relay. The coil has to trigger at about 4V and less than 30 mA. For any larger relay you will need a transistor driver.
I think your snubbing diode is wrong way around. It will short the input to Ground. It's supposed to be reverse-biased (not conducting) when the relay is ON.
johnwasser:
You will need a VERY small relay. The coil has to trigger at about 4V and less than 30 mA. For any larger relay you will need a transistor driver.
True... Well, allow me to make the following modification: I'm now going to power the relay on a different circuit like such:
my big question is what happens if both arduino do a digitalWrite on PIN 2 at the same moment? Can it be damaging?
johnwasser:
I think your snubbing diode is wrong way around. It will short the input to Ground. It's supposed to be reverse-biased (not conducting) when the relay is ON.
oops... my apologies.
MadCat:
my big question is what happens if both arduino do a digitalWrite on PIN 2 at the same moment? Can it be damaging?
No.
// Per.