Mutual powering of two Arduinos with USB

Other Hardware General Electronics
1

Hi everybody,

I'm working on a project with two Arduinos Micro that need to be connected to two different computers (USB).

I need that both of them were powered as soon as one of them is powered by the computer's USB port, without being an issue when both are...

I posted about it on the french section and some nice guys gave me some advice about using shottky diodes / mosfets P, but I don't know electronics enough to know exactly how to achieve my goal (without risking something bad with boards or worse USB ports).

Does anyone have a solution for this ?

Thanks a lot !

2

I'd use the MOSFET solution that many modern Arduinos use to activate the VIN over USB.

3

Hi pylon, and thanks for your answer.

Let's make sure I understood your words... Are you suggesting that I use MOSFETS to close 5V line from the other board when USB power is detected ?

In this case, my basic understanding of this leads me to the following problem :

If I do something like "if there is no power on 5V pin of Arduino A (meaning USB is disconnected), let 5V come from Arduino B to 5V pin of Arduino A", it would be making immediately the condition become no longer true...

How to deal with that ?

Thanks !

4

You made a smart decision not to wire it up when you are not comfortable with it. You could be purchasing another computer with this design. Design your interface such that it determines when the other is ready. This will save you from all those wiring problems.

5

So this is sounding like the dread XY Problem? :dizzy_face:

6

Using an autoswitching power muxer (p.e. TI TPS2112)?