File content as of revision 1:df9d6f3886f6:

//**************************************************//
// Application to switch a light or other output    //
// whenever the correct handclapping pattern is     //
// detected. An external handclap detection board   //
// is used (works as a SR-latch).                   //
//                                                  //
// Ferry Musters & Thom Grasso - 26/06/2015         //
// Electrical Engineering - Hogeschool Utrecht      //
//**************************************************//
// TODO:
// DONE! Must have:   - Reset timer and measurements after (4sec?) timeout
// DONE! Must have:   - Detect fixed pattern (2 claps)
// Must have:   - Detect fixed pattern (3+ claps)
// Could have:  - Make user defined patterns (learn the device the pattern)

#include "mbed.h"

void BlinkLed(char color, float time);

//-------------------[ Parameters ]------------------
const int timeout_ms = 1000;
const int allowedError = 200; //Allowed time difference between clap and set clap pattern

const int clapPattern[] = {0, 500}; //initial clap pattern (in ms)

//-------------------[ Variables ]-------------------
DigitalOut led_red(LED_RED);
DigitalOut led_blue(LED_BLUE);
DigitalOut led_green(LED_GREEN);
InterruptIn userSwitch(SW3);


DigitalOut boardGnd(D4); //pins
DigitalOut boardVcc(D5);
//InterruptIn boardClap(SW2);
InterruptIn boardClap(D6);
DigitalOut boardReset(D7);

Serial output(USBTX, USBRX);
Timer timer; //global timer
int clapData[100]; //buffer to save clap times
int currentClap = 0; //counter to keep track of current clap in buffer
int printedClap = 0; //counter to keep track of printf'ed claps


//-------------------[ Interrupts ]-------------------
void ClapDetected(void) //interrupt function for boardClap pin
{
    clapData[currentClap++] = timer.read_ms(); //save clap time and increment counter

    led_blue= 0;    //blink a led to show detected clap
    boardReset = 1; //reset the clap detecter board with a reset pulse
    wait(0.1); //wait to show led and also avoid handclap 'bounces'
    boardReset = 0;
    led_blue = 1; //The LED pin is inverted so '1' means LED off
}

void DemoPattern(void)  //interrupt function for userSwitch pin
{
    const float demoBlinkLength = 0.05; //led blink length in ms
    int amountOfClaps = sizeof(clapPattern) / sizeof(clapPattern[0]);
    wait(0.3);
    BlinkLed('r', demoBlinkLength); //blink the first clap
    for(int i = 1; i < amountOfClaps; i++) { //blink the second and next claps
        float delaytime = (clapPattern[i]-clapPattern[i-1])/1000.0 - demoBlinkLength;
        output.printf("Blinking clap %d for %.2f second\r\n", i, delaytime);
        output.printf("clapPattern[i] = %d\r\n", clapPattern[i]);
        output.printf("clapPattern[i-1] = %d\r\n", clapPattern[i-1]);
        wait(delaytime);
        BlinkLed('r', demoBlinkLength);
    }
}

//-------------------[ Functions ]-------------------
void Initialize()
{
    timer.start();
    boardVcc = 1;
    boardGnd = 0;
    boardReset = 0;
    led_red = 1;
    led_green = 1;
    led_blue = 1;
    boardClap.rise(&ClapDetected);
    userSwitch.rise(&DemoPattern);
}

void PrintClaps()
{
    if(printedClap < currentClap) { //if the last clap isn't printed yet
        output.printf("* Detected clap %d: %d\r\n", ++printedClap, clapData[printedClap]); //debug the clap
    }
}

bool CheckTimeout() //check if clap timeout occurs(when last clap is more then x seconds ago)
{
    return ((currentClap > 0) && (timer.read_ms() > (clapData[currentClap-1] + timeout_ms)))
}

void ResetMeasurement() //reset counters to start new measurement
{
    output.printf("--- Timeout. %d claps and took %.2fs in total ---\r\n", currentClap, (clapData[currentClap-1] - clapData[0])/1000.0);
    currentClap = 0;
    printedClap = 0;
}

bool CheckClapPattern() //check if clapped pattern matches
{
    //CURRENT VERSION SUPPORTS JUST 2-clap patterns
    output.printf("Check if %d is equal to %d.\r\n", (sizeof(clapPattern)/sizeof(clapPattern[0])), currentClap);

    if((sizeof(clapPattern)/sizeof(clapPattern[0])) != currentClap) return false; //if nr of claps is not equal return mismatch

    int realClapDelta = clapData[1] - clapData[0]; //measured clap pattern
    int requiredClapDelta = clapPattern[1] - clapPattern[0]; //set clap pattern

    int maxClapDelta = requiredClapDelta + allowedError;
    int minClapDelta = requiredClapDelta - allowedError;
    if((realClapDelta > minClapDelta) && (realClapDelta < maxClapDelta)) return true;
    else return false;
}

void BlinkLed(char color, float time) //Blink led ('r', 'g' or 'b') for given time (float in sec)
{
    if(color == 'r') led_red = !led_red;
    if(color == 'g') led_green = !led_green;
    if(color == 'b') led_blue = !led_blue;
    wait(time);
    if(color == 'r') led_red = !led_red;
    if(color == 'g') led_green = !led_green;
    if(color == 'b') led_blue = !led_blue;
}

//-------------------[ Main ]-------------------
int main()
{
    Initialize(); //initialize all required components and interrupts

    while (true) {
        PrintClaps(); //update the serial terminal to print all detected claps

        if( CheckTimeout() ) { // if timeout happened -> clap pattern ended
            bool clapMatches = CheckClapPattern(); //check if claps match set pattern
            if(clapMatches) BlinkLed('g', 0.5); //pattern match -> blink green
            else BlinkLed('r', 0.5); //pattern mismatch -> blink red
            ResetMeasurement();
        }
    }
}