/* Divergence: A wearable EMF detector with haptic and sonic feedback

* By Afroditi Psarra http://afroditipsarra.com

*

* July 2014

*

* Circuit:

* Adafruit Flora

* 2 handmade copper coils connected on analog pins A7 and A9 and grounded with 3.6 M Ohms resistors

* 1 vibration motor on digital pin 10 (PWM pin)

* 1 mini jack - soundOut connected to digital pin 12 via a low-pass filter with a 47uF

* and a zipper slider < 100 K Ohms (the zipper uses the uC internal pullup resistor

*/

#define soundOut 12 // sound output connected to digital pin 12

#define vibe 10 // vibration motor located on the chest connected to digital pin 3

#define coilRight A7 // coil antenna located on the right wrist connected to analog pin A7

#define coilLeft A9 // coil antenna located on the left wrist connected to analog pin A9

#define NUMREADINGSRIGHT 15 // raise this number to increase data smoothing

#define NUMREADINGSLEFT 15 // raise this number to increase data smoothing

int senseLimitRight = 125; // raise this number to decrease sensitivity on the right probe(up to 1023 max)

int senseLimitLeft = 125; // raise this number to decrease sensitivity on the left probe(up to 1023 max)

int probeRight; // probe readings from the right coil

int probeLeft; // probe readings from the left coil

// variables for smoothing

int readingsRight[NUMREADINGSRIGHT]; // the readings from the analog input A7

int indexRight = 0; // the index of the current reading from the right coil

int totalRight = 0; // the running total pf the right coil

int averageRight = 0; // final average of the probe reading from the right coil

int readingsLeft[NUMREADINGSLEFT]; // the readings from the analog input A9

int indexLeft = 0; // the index of the current reading from the left coil

int totalLeft = 0; // the running total of the left coil

int averageLeft = 0; // final average of the probe reading from the left coil

void setup() {

//Serial.begin(9600); // initialize the serial communication (for debugging-calibrating only)

pinMode(soundOut, OUTPUT); // initialize the mini jack/speaker as an output

pinMode(A11, INPUT_PULLUP); // use the internal pullup resistor on the same pin as above

pinMode(vibe, OUTPUT); // initialize the mini jack/speaker as an output

}

void loop() {

coilProbeRight();

coilProbeLeft();

// Serial.print(averageRight);

// Serial.print(" ");

// Serial.println(averageLeft);

delay(1);

}

void coilProbeRight() {

probeRight = analogRead(coilRight);

if(probeRight >= 1){ // if the reading isn't zero, proceed

probeRight = constrain(probeRight, 1, senseLimitRight); // turn any reading higher than the senseLimit value into the senseLimit value

probeRight = map(probeRight, 1, senseLimitRight, 1, 1023); // remap the constrained value within a 1 to 1023 range

totalRight -= readingsRight[indexRight]; // subtract the last reading

readingsRight[indexRight] = probeRight; // read from the sensor

totalRight += readingsRight[indexRight]; // add the reading to the total

indexRight = (indexRight + 1); // advance to the next index

if (indexRight >= NUMREADINGSRIGHT) // if we're at the end of the array...

indexRight = 0; // ...wrap around to the beginning

averageRight = totalRight / NUMREADINGSRIGHT; // calculate the average

}

int vibeIntensity = map(averageRight, 32, 768, 0, 255); // map the average to pwm values

analogWrite(vibe, vibeIntensity); // make the motor vibrate depending on the average

int freq = map(averageRight, 32, 768, 880, 60);

int dur = map(freq, 880, 60, 10, 1000);

tone(soundOut, freq, dur);

}

void coilProbeLeft() {

probeLeft = analogRead(coilLeft);

if(probeLeft >= 1){ // if the reading isn't zero, proceed

probeLeft = constrain(probeLeft, 1, senseLimitLeft); // turn any reading higher than the senseLimit value into the senseLimit value

probeLeft = map(probeLeft, 1, senseLimitLeft, 1, 1023); // remap the constrained value within a 1 to 1023 range

totalLeft -= readingsLeft[indexLeft]; // subtract the last reading

readingsLeft[indexLeft] = probeLeft; // read from the sensor

totalLeft += readingsLeft[indexLeft]; // add the reading to the total

indexLeft = (indexLeft + 1); // advance to the next index

if (indexLeft >= NUMREADINGSLEFT) // if we're at the end of the array...

indexLeft = 0; // ...wrap around to the beginning

averageLeft = totalLeft / NUMREADINGSLEFT; // calculate the average

}

int vibeIntensity = map(averageLeft, 0, 1023, 0, 255); // map the average to pwm values

analogWrite(vibe, vibeIntensity); // make the motor vibrate depending on the average

int freq = map(averageLeft, 0, 1023, 880, 60);

int dur = map(freq, 880, 60, 10, 1000);

tone(soundOut, freq, dur);

}