//Particle Photon code

//the other side will be the reverse. i.e subscribe_channel = "diot2018/tictactoe/particle2" ;

const char *subscribe_channel = "diot2018/smiley/particle1" ;

const char *publish_channel = "diot2018/smiley/particle2" ;

const int FLEX_PIN = A0; // Pin connected to voltage divider output

// Measure the voltage at 5V and the actual resistance of your

// 47k resistor, and enter them below:

const float VCC = 4.98; // Measured voltage of Ardunio 5V line

const float R_DIV = 47500.0;

// Upload the code, then try to adjust these values to more

// accurately calculate bend degree.

const float STRAIGHT_RESISTANCE = 37300.0; // resistance when straight

const float BEND_RESISTANCE = 90000.0; // resistance at 90 deg

Servo myservo;// create servo object using the built-in Particle Servo Library

int button = D1;    //declare variable for button

int servoPin = D0;  //declare variable for servo

// Read the ADC, and calculate voltage and resistance from it

float getFlexAngle() {

  int flexADC = analogRead(FLEX_PIN);

  float flexV = flexADC * VCC / 1023.0;

  float flexR = R_DIV * (VCC / flexV - 1.0);

  Serial.println("Resistance: " + String(flexR) + " ohms");

  // Use the calculated resistance to estimate the sensor's

  // bend angle:

  float angle = map(flexR, STRAIGHT_RESISTANCE, BEND_RESISTANCE,

                   0, 90.0);

  Serial.println("Bend: " + String(angle) + " degrees\n");

  return angle ;

}

//drives the motor to correct angle

void setFlexAngle(float angle) {

  Serial.print("Setting servo to " + String(angle) + "degrees\n") ;

  myservo.attach(servoPin) ;

  myservo.write(angle) ;

  delay(200) ; //short delay to allow motor to move

  mysevo.detach() ;

}

//publish to cloud

void publishAngle(float angle) {

  s = String(angle) ;

  Particle.publish(publish_channel, s) ;

  return ;

}

void subscribeHandler(const char *event, const char *data) {

  if(!data) {

    return ; // nothing sent

  }

  float angle = String(data).toFloat() ;

  setFlexAngle(angle) ;

  return ;

}

void setup()

{

  Serial.begin(9600);

  //setup flex sensor

  pinMode(FLEX_PIN, INPUT);

  //setup servo

  myservo.attach(servoPin); //Initialize the servo attached to pin D0

  //quick servo test

  myservo.write(90); //set servo to furthest position

  delay(100); //delay to give the servo time to move to its position

  myservo.write(0); //reset servo position

  myservo.detach(); //detach the servo to prevent it from jittering

  //subscripe to channel

  Particle.subscribe(subscribe_channel, subscribeHandler) ;

}

void loop()

{

  int delay_period = 1000 ; // set to desired amount to prevent too many messages sent

  float curr_angle = getFlexAngle() ;  //get angle of the flex sensor

  publishAngle(curr_angle) ; //publish angle to other device

  delay(delay_period);

}