Get and replay analog audio input

Other Hardware Audio
1

I'm attempting to create a repeater controller for mobile radio. The device would listen for audio input on a 3.5mm audio line in, record the message, and immediate replay the message on an audio line out. It's not important if the line in and out are the same jack.

Is this as simple as reading the analog input, storing it, and sending that same analog signal back out? The audio input is voice data so sample rate can be low. There's no need to do any processing of this data, though a future iterate could looks for dial tone codes and update settings.

I'm looking for guidance on if this is the right approach, or it's more complex than this. I've started some basic circuit design: I know I need to use midpoint biasing to get the analog audio input, but I want to know if that's even the right approach.

2

In principle, yes - but the devil, as always, is in the detail.

How will you store it?
Even at low sample rates, it's going to be a lot of data.
Even toll quality voice is 64K bits every second.

How are you going to detect that a message has started, and when it ends?

3

No problem with e.g. a RasPi, having audio I/O and enough internal or external memory.

1 Like
4

The size of the connector is irrelevant - but you will need to know the signal level.

5

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.