Arduino UNO R4 with an Analog Microphone

The easiest way to “record” audio with an Arduino UNO R4 is by using an analog microphone which can be connected to any analog pin.

For my test I was using a MCP6022 Microphone Sensor.

Arduino Sketch

There are no surprises here because we can use the AnalogAudioStream as audio source:

#include "AudioTools.h"

AnalogAudioStream in; 
AudioInfo info(8000, 1, 16);
CsvOutput<int16_t> out(Serial); // ASCII output stream 
StreamCopy copier(out, in); // copy i2sStream to CsvOutput

// Arduino Setup
void setup(void) {
  Serial.begin(115200);
  AudioLogger::instance().begin(Serial, AudioLogger::Info);

  // RX automatically uses port 0 with pins GPIO34,GPIO35
  auto cfgRx = in.defaultConfig(RX_MODE);
  //cfgRx.start_pin = A1; // define pin - default is A0
  //cfgRx.is_auto_center_read = true; // default is true
  cfgRx.copyFrom(info);
  in.begin(cfgRx);

  // open output
  out.begin(info);

}

// Arduino loop - copy data 
void loop() {
  copier.copy();
}

The potentially upated source code for this “streams-adc-serial” example can be found in the Project and on Github

Pin Mapping

MIC – UNO
VCC – 5V
GND – GND
OUT – A0

When no pin is defined in the configuration, we automatically use A0.

Result

I suggest to record a sine wave that was generated e.g. with the help of https://onlinetonegenerator.com
Here is the result displayed with the help of the Arduino Serial Plotter:

We can see that this resembles a sine wave that is centered around 0, but the quality is not perfect. However this is still good enough for further processing: We can e.g. use this as input into FFT to analyse the frequency spectrum and display the result on the LED matrix…