In&Out Program

[eatbas]

Hello all,

I'm trying to make a simple in-and-out program using port MIC-C to input my microphone. Although I built an amplification circuit to increase its loudness, I still cannot hear myself talking. I do, however, hear myself blowing to the microphone.

The microphone I'm using is SPH1642HT5H-1, and the code I'm using for my in and out program is:

#include <Audio.h>

AudioClass *theAudio;

void setup() {
  theAudio = AudioClass::getInstance();
  theAudio->begin();
  /* Setup a baseband audio path from mic input to line out */
  theAudio->setThroughMode(AudioClass::MicIn, AudioClass::None,
                           true, 100, AS_SP_DRV_MODE_LINEOUT);
  theAudio->setVolume(50);
}

void loop() {
  /* Do nothing */
}

However, no matter what I do, I cannot get a loud enough signal where I can hear myself.

SPH1642HT5H-1 is soldered to a PCB where the output from the microphone is directly fed into the MIC-C and MIC-C's Ground pins and to a 3.3V supply obtained from the SPRESENSE.

Can anyone help me with this, please?

[jens6151 0 1 1]

@eatbas
Although I have a different microphone (link). I experienced very low input. It was better after setting the gain to max. Can you try?

theRecorder->setMicGain(210);

Otherwise please double check the instructions
https://developer.sony.com/develop/spresense/docs/hw_docs_lte_en.html#_microphone_usage

For analog MEMS microphones the bias pins on JP10 provide power to the MEMS microphone, connect the bias pin of JP10 to the MEMS microphones power supply pin.