Serial connection redundance?

Hi,

I am working on a project where I communicate with a sensor via a serial connection. Due to the fact that it would be very bad when my Arduino fails (hardware defect, etc.) I would like to have a second Arduino that is also communicating via serial with this sensor.
Would it be possible that Arduino 1 communicates in both directions with the sensor (tx and rx) and Arduino 2 is just listening via its rx pin?
Or is there any better approach?

I would be very grateful if you could give me some advice :slight_smile:

Kind regards,
Tom

You can connect a second Arduino as listener no problem. But is the sensor sending data when it will not receive anything or when it receives garbage?

And an Arduino itself is not very likely to fail. At least not the chip it you don't do stupid things with it like over stressing pins. Things like power supplies are more likely to fail. Or just a bug in your software, but that's why we debug :slight_smile:

Would it be possible that Arduino 1 communicates in both directions with the sensor (tx and rx) and Arduino 2 is just listening via its rx pin?

Sure, you can do that.

There's a general rule that you shouldn't wire to or more outputs together, but it's OK to connect two or more inputs. At some point, too may inputs (receivers/listeners) will "overload" the output but we won't worry about that.

One way to think about it is that you can have 1 person (a "transmitter") speaking to 100 listeners ("receivers") at the same time but you can't have 100 speakers talking all at the same time to one listener.

Of course there are exceptions, and these are just generalizations... Ethernet & Wi-Fi work both ways and if two things transmit at the same time that's all handled in the protocol. Or, you can have a choir with 100 singers, etc.

Or is there any better approach?

It's hard to say what's "better" because we don't know what's most-likely to fail.

Thank you very much for your reply septillion and DVDdoug! I really appreciate your fast help :slight_smile:
My team does not have any experience with Arduinos and their greatest fear is that it fails.
I think it would be necessary to build a complete redundant system but that would be to expensive.
If I cannot change their mind I will try this low budget solution :slight_smile:

This is, if it fails, why would the backup not have failed?

And what is so important it may not fail?