3 Microphones recording to SD card
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3 Microphones recording to SD card

by michael007 on Fri Dec 07, 2012 4:38 pm


I have been asked to build a circuit that is recording the sound coming from 3 analog microphones (1 line each) into a SD card for multiple hours. The files on the SD card must be timestamped with the current time (so a RTC would be good).

Which MCU should I use?
If needed, we can have 3 individual circuits with each its own SD card. But I am specifically looking for a quick solution to start with.

The ease of programming is important for me.

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Re: 3 Microphones recording to SD card

by adafruit_support_mike on Sat Dec 08, 2012 3:10 pm

What kinds of signals are you trying to record? The solutions are different for 'three always-on signals', 'three sources but only one generates a signal at any given time', and 'three sources that are on some times, off others, and might overlap'.

If the signals take turns, you can run them through a multiplexer and reduce the recording end of the problem to a single input. If you need three more or less independent input lines, the easiest solution is also the most expensive one.. throw hardware at it.

A second question would be, "how do you know when to start recording?" For three continuous signals that would be trivial, but for three signals that come on and off at random times it could be challenging.

A third would be, "how do you intend to use the recorded input?" Low-quality audio offers you more wiggle room than high-quality.
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