Serial comms with 3.7V powered arduinos


I have two arduinos powered by 3.7V lithium ion batteries. They send and receive serial data between them.

Is there any potential problems later on that may result by powering the boards with 3.7V and using serial?

Appreciate any help.


What sort of arduino? The ones that run at 16MHz have a minimum voltage for that frequency and that is higher than the voltage you are using. So you are running them out of spec, while it might work under some conditions as you have found running anything out of spec is never a good idea.

What sort of arduino

I am currently running a Uno and Mega and all seems to be working fine now. But i hope to just use Megas later on.

What distance and cable are you using, remember RS232 had high voltages to avoid noise pickup on the line interfering ( I seem to recall )

What distance and cable are you using

At the moment the distance is about 5cm using PCB wire.

Ok, thats not an issue then.

Ok, thats not an issue then.

Thanks, that's good to know.

So, is there a problem using two Megas then as opposed to two Unos?

I dont know ... GrumpyMike ?

No more of a problem than with Unos. They are both running out of spec.

They are both running out of spec.

I am currently have the two arduinos talking to each other to make sure that the commands they send and receive are correct. Eventually only one arduino will talk to a 3.3V device using serial communication. They will both operate from a 3.7V lithium ion battery.

To be able to use the arduino so that it is not running out of spec, should i boost the battery voltage to 5V and then use a logic shifter (

Is this the best way to handle this?


Does anyone have any ideas about my previous post?