Read a serial communication between two other boards

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1

I'm trying to basically spoof a serial communication between two other boards. Is that feasible?

To give more context:
I have two boards that communicate using serial communication. I want to understand how they communicate to reverse engineer one of them (that has an issue in it)

2

Being able to do the spoof thing may depend more on the skill of the programmer.

3

Yes, that can be done. I would suggest you use an Mega which has multiple hardware serial ports. Use the default Serial for you connection to your PC. Use Serial1 connected to board #1 and Serial2 connected to board #2.

When you see a char available on Serial1 you read it, send it to Serial and Serial2
When you see a char available on Serial2 you read it, send it to Serial and Serial1

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4

Or buying a cheap logic analyzer, which comes for about 10 bucks.
This might be more suitable to find out the right bautrate, etc.

But keep an eye on the voltages of the other boards. If they are no Arduinos or something, they might fry your Mega or logic analyzer.

5

I don't think that you have to intercept. You can hook RX1 of the mentioned Mega to TX of one board (in parallel with existing wiring) and RX2 to TX of the other board (again in parallel with the existing wiring).

6

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