HOW to Use Sound Sensor on Raspberry Pi with ESP32
Overview
In this kit, there is a Keyestudio DIY electronic block and a sound sensor. In the experiment, we test the analog value corresponding to the sound level in the current environment with it. The louder the sound, the larger the ADC, DAC and the voltage value, and the “shell” window will display the test results.
Working Principle
It uses a high-sensitive microphone component and an LM386 chip. We build the circuit with the LM386 chip and amplify the sound through the high-sensitive microphone. In addition, we can adjust the sound volume by the potentiometer. Rotate it clockwise, the sound will get louder.
Components
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ESP32 Board*1 |
ESP32 Expansion Board*1 |
Keyestudio DIY Sound Sensor*1 |
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3P Dupont Wire*1 |
Micro USB Cable*1 |
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Connection Diagram
Test Code
//**********************************************************************************
/*
* Filename : MicroPhone
* Description : Read the basic usage of ADC，DAC and Voltage
* Auther : http//www.keyestudio.com
*/
#define PIN_ANALOG_IN 34 //the pin of the Sound Sensor
void setup() {
Serial.begin(9600);
}
//In loop()，the analogRead() function is used to obtain the ADC value,
//and then the map() function is used to convert the value into an 8-bit precision DAC value.
//The input and output voltage are calculated according to the previous formula,
//and the information is finally printed out.
void loop() {
int adcVal = analogRead(PIN_ANALOG_IN);
int dacVal = map(adcVal, 0, 4095, 0, 255);
double voltage = adcVal / 4095.0 * 3.3;
Serial.printf("ADC Val: %d, \t DAC Val: %d, \t Voltage: %.2fV\n", adcVal, dacVal, voltage);
delay(200);
}
//**********************************************************************************
Test Result
Connect the wires according to the experimental wiring diagram, compile and upload the code to the ESP32. After uploading successfully，we will use a USB cable to power on, open the serial monitor and set the baud rate to 9600. We need to press the reset button on the ESP32, then the serial monitor will display the sound sensor’s ADC value, DAC value and voltage value. Rotate clockwise the potentiometer and speak at the MIC. Then you can see the analog value get larger, as shown below:
