Clap Light Project (X02)

About

This project uses the Microphone to detect clapping noises and turns on or off the LED if it senses two claps with a second pause inbetween. This project was designed for the second generation mCookie Maker kits (102 Basic, 202 Advanced and 302 Expert kits).

Required Materials

• 1 x mCookie Core
• 1 x mCookie USB TTL (102 Kit) or 1 x mBattery (202/302 Kit)
• 1 x mCookie Sensor Hub
• 1 x Single ColorLED
• 1 x Microphone Sensor
• 1 x Buzzer
• 3 x Sensor Cable
• 1 x MicroUSB Cable

Build

1. Connect the Single ColorLED to the Sensor Hub on Pin A0/A1
2. Connect the Buzzer to the Sensor Hub on Pin 6/7
3. Connect the Microphone to the Sensor Hub on Pin A2/A3
4. Grab the mCookie USBTTL or mBattery and Stack the mCookie Core on top.
5. Stack the mCookie Sensor on top of that.
6. Plug in the MicroUSB cable to the mCookie USBTTL or mBattery to a computer.

Program

Copy and paste the code below and upload.

#include <stdint.h>

#define MIC_PIN A2
#define BUZZER_PIN 6
#define LED_PIN A0

//The minimum amount of clap loudness to be registered as a clap
const uint16_t CLAP_LOUDNESS_THRESHOLD = 400;

//The maximum loudness between the two claps
const uint16_t SILENT_LOUDNESS_THRESHOLD = 200;

//The amount of time from the detection of the first clap until testing if there is silence
const uint16_t PAUSE_TIME = 250;

volatile uint16_t mic_value;
unsigned long second_clap_timer;

bool leds_are_on = false;


void setup() {
  pinMode(LED_PIN, OUTPUT);
  
  Serial.begin(9600);
  // put your setup code here, to run once:
  pinMode(MIC_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:


  //Take in mic reading for the first clap
  uint16_t mic_value = analogRead(MIC_PIN);
  //Check if it is greater than the threadhold
  if ( mic_value > CLAP_LOUDNESS_THRESHOLD ) {
    Serial.println("First clap detected!");
    delay(PAUSE_TIME); //Wait PAUSE_TIME
    //Read in a new mic value for the silence between the claps
    mic_value = analogRead(mic_value);
    Serial.println(mic_value);
    //If the value is under the threshold, then it is silent
    if ( mic_value < SILENT_LOUDNESS_THRESHOLD ) {
      Serial.println("Silence detected!");
      //wait a bit of time beforce looking for the second clap
      //delay(PAUSE_TIME);
      second_clap_timer = millis();
      while(((millis() - second_clap_timer) < 2000)){
        mic_value = analogRead(MIC_PIN);
        if(mic_value > CLAP_LOUDNESS_THRESHOLD){
          Serial.println("Second clap detected!");
          tone(BUZZER_PIN, 3038, 200);
          if( leds_are_on == false ){
            activate_light();
          }
          else{
            deactivate_light();
          }
          delay(1000);
          break;
        }
      }
      
    }
  }

  delay(1);
}

void activate_light() {
  digitalWrite(LED_PIN, HIGH);
  leds_are_on = true;
}

void deactivate_light() {
  digitalWrite(LED_PIN, LOW);
  leds_are_on = false;
  return;
}

Debugging

• Open the Serial monitor. Information will print out when the first clap is detected as "First clap detected!".
• Then a value will print out which is the silent value. If it is under the threshold, "Silence detected!" will print.
• "Second clap detected!" will print if it detected a second clap.

Tweaking

Variables can be edited to change the threshold / detection value for various functions to better fine tune to your environment.

CLAP_LOUDNESS_THRESHOLD will change the clapping loudness trigger point. Lower values means a weaker noise level is detected as a clap.

• Adjustable between 0 ~ 1023
• Default is 400

SILENT_LOUDNESS_THRESHOLD will change the silent registry level. Higher values will mean that higher noise levels will be registered as a silence.

• Adjustable between 0 ~ 1023
• Default is 200

PAUSE_TIME will change the time in which you are required to pause between claps in milliseconds. Lower values will detect faster claps, but there is settling time on the Microphone, which means too short of a pause time won't be detectable as silence. Default is 200 milliseconds or 1/5 of a second.

Usage

Clap once, wait about 1 second, then clap another time. The LED should turn on and a beep noise will occur. Repeating the sequence will turn off the LED.