Changing to External Microphones

#1

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:

audioHardware.inputSelect(TYMPAN_INPUT_ON_BOARD_MIC);

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:

audioHardware.inputSelect(TYMPAN_INPUT_JACK_AS_MIC);

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

audioHardware.inputSelect(TYMPAN_INPUT_JACK_AS_LINEIN);

I hope that this helps!

Chip

Switching Inputs
#2

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:

Style1
Style1.png1088×695 256 KB

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

Style
Style.png1300×750 261 KB

Chip

#3

Hi,

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)”;

#4

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

audioHardware.inputSelect(TYMPAN_INPUT_JACK_AS_LINEIN);

I that this is what you needed!

Chip