Changing to External Microphones

I’ve received questions about how to switch the Tympan from using its built-in microphones to using external microphones via the red microphone jack.

The simplest answer is to look for a line that says “inputSelect”. By default, the example programs probably look like:


If you want to use an external microphone via the microphone jack (and if you want the Tympan to supply a voltage bias to power the mic), you’ll want to change this line of code to read something like:


Or, if you want to use the jack as a line-input (ie, no voltage biasing), you’d change the line to read:


I hope that this helps!


If you want more examples, you can look at the Tympan example programs. Generally, there are two styles in the example programs.

Here’s the first style that you might see:

And here’s the second style that you might see:



Thanks for the inputs
If I am using the teensy audio board , to switch the inputs between mic in and line in, which function should I call instead of this statement : “audioHardware.inputSelect(TYMPAN_INPUT_JACK_AS_MIC)”;

As discussed in the first post, if you want to use the pink jack as a line level input, you use:


I that this is what you needed!