sketch_window_manipulator.ino

// Constants
const int upLed = 13;
const int pendingLed = 12;
const long pendingLedInterval = 500;
const int spwPin = 5;
const long pulsePerMile = 4000; // For Honda Element
const int upSpeed = 40;
const long upTime = 60000; // 1 Minute
const int dnSpeed = 30;
const long dnTime = 30000; // 30 Seconds
const long mphFactor = 3600000 / pulsePerMile; // Figure what 1 mph is in pulses per hour

// Globals
unsigned long lastSpeedCheck = 0;
unsigned long lastPendingTime = 0;
boolean upStatus = false;
boolean pendingStatus = false;
long timeSincePending = 0;
unsigned long pendingLedLast = 0;
int pendingLedState = LOW;

void setup() {
  Serial.begin(9600);
  pinMode(upLed, OUTPUT);
  pinMode(pendingLed, OUTPUT);
  TCCR1A = 0; // reset timer/counter control
  digitalWrite(upLed, LOW);
  digitalWrite(pendingLed, LOW);
  bitSet(TCCR1B, CS12);
  bitSet(TCCR1B, CS11);
  lastSpeedCheck = millis();
}

void loop() {
  int currentSpeed = getSpeed();
  if (currentSpeed < dnSpeed && upStatus) {                   // We are below the down threshold, and we're up
    if (lastPendingTime == 0) {
      lastPendingTime = millis();  // If we don't have a pending time, we just started pending
    }
    pendingStatus = true;
    timeSincePending = millis() - lastPendingTime;            // How long have we been pending?
    if (timeSincePending > dnTime) {                          // If we've been pending long enough...
      doDnWindow();                                           // Roll down the window
      lastPendingTime = 0;                                    // Clear the pending time
      pendingStatus = false;                                  // We're no longer pending
    }
    blinkPendingLed();
  }
  else if (currentSpeed > upSpeed && !upStatus) {             // We are above the up threshold, and we're down
    if (lastPendingTime == 0) {
      lastPendingTime = millis();  // If we don't have a pending time, we just started pending
    }
    pendingStatus = true;
    timeSincePending = millis() - lastPendingTime;            // How long have we been pending?
    if (timeSincePending > dnTime) {                          // If we've been pending long enough...
      doUpWindow();                                           // Roll down the window
      lastPendingTime = 0;                                    // Clear the pending time
      pendingStatus = false;                                  // We're no longer pending
    }
    blinkPendingLed();
  } else {
    lastPendingTime = 0;                                      // Clear the pending time
    pendingStatus = false;                                    // We're not pending
    if (pendingLedState == HIGH) {
      digitalWrite(pendingLed, LOW);
    }
  }
}

void blinkPendingLed() {
  unsigned long currentMillis = millis();                     // Grab the current time
  if (currentMillis - pendingLedLast >= pendingLedInterval) { // Has it been long enough since we blinked?
    pendingLedLast = currentMillis;                           // Update the time we last blinked
    pendingLedState = pendingLedState == LOW ? HIGH : LOW;    // Change the state
    digitalWrite(pendingLed, pendingLedState);
  }
}

void doUpWindow() {
  digitalWrite(upLed, HIGH);
  upStatus = true;  // TODO: This will become I2C code to trigger things on the remote relay board
}

void doDnWindow() {
  digitalWrite(upLed, LOW);
  upStatus = false;  // TODO: This will become I2C code to trigger things on the remote relay board
}

float getSpeed() {
  TCCR1B = 0;                                 // Stop counting (No Clock Source)
  int pulseCount = TCNT1;                     // Get the count
  int timePassed = millis() - lastSpeedCheck; // Get time passed

  TCNT1 = 0;                                  // Reset the Count
  bitSet(TCCR1B, CS12);                       // Needed for following bits
  bitSet(TCCR1B, CS11);                       // Book says rising edge, datasheet says falling edge
  bitSet(TCCR1B, CS10);                       // Datasheet says this and previous for rising edge
  lastSpeedCheck = millis();                  // Update the time we last checked speed
  Serial.write("Current Speed: ");
  Serial.print(calculateMPH(pulseCount, timePassed);
               return calculateMPH(pulseCount, timePassed);
}

float calculateMPH(int pulseCount, int timePassed) {
  return pulseCount / timePassed * mphFactor; // ( (Pulse_Count / Millis_Passed) * 3600000) / Pulses_per_Mile = MPH
}                                             // (3600000 / Pulses_per_Mile) = mphFactor Const