/* Battery Test Serial Writer
 * Sends a serial heartbeat that indicates that battery power
 * is still sufficient. When the battery dies, the heartbeat will stop
 */

int ledPin = 13;   // select the pin for the LED

int servoPin = 2;     // Control pin for servo motor
int minPulse = 500;   // Minimum servo position
int maxPulse = 2500;  // Maximum servo position
int pulse = 0;        // Amount to pulse the servo

unsigned long lastPulse = 0;    // the time in milliseconds of the last pulse
int refreshTime = 20; // the time needed in between pulses

int analogValue = 0;  // the value returned from the analog sensor
int analogPin = 0;    // the analog pin that the sensor's on
unsigned long startTime = 0;
boolean moveUp = false;

void setup() {
  pinMode(ledPin,OUTPUT);   // declare the LED's pin as output
  pinMode(servoPin, OUTPUT);  // Set servo pin as an output pin
  pulse = minPulse;           // Set the motor position value to the minimum
  beginSerial(9600);        // connect to the serial port
  blinkLED(ledPin, 2, 100);
}

void loop() {
unsigned long now = millis();

  if (now - startTime > 1000) {
    //  analogValue = analogRead(analogPin);      // read the analog input

Serial.print("now: ");
Serial.print(now, DEC);
Serial.print("  startTime: ");
Serial.println(startTime, DEC);


    if (moveUp == true) { 
      analogValue = 768;
      pulse = (analogValue * 19) / 10 + minPulse;    // convert the analog value
      moveUp = false;
    }

    else if (moveUp == false) { 
      analogValue = 255;
      pulse = (analogValue * 19) / 10 + minPulse;    // convert the analog value
      moveUp = true;
    }

    // to a range between minPulse
    // and maxPulse. 
    int printValue = analogValue;
    Serial.println(printValue);
    startTime = now;
  }



  // pulse the servo again if rhe refresh time (20 ms) have passed:
  if (millis() - lastPulse >= refreshTime) {
    digitalWrite(servoPin, HIGH);   // Turn the motor on
    delayMicroseconds(pulse);       // Length of the pulse sets the motor position
    digitalWrite(servoPin, LOW);    // Turn the motor off
    lastPulse = millis();           // save the time of the last pulse
  }

}




// this function blinks the an LED light as many times as requested
void blinkLED(byte targetPin, int numBlinks, int blinkRate) {
  for (int i=0; i<numBlinks; i++) {
    digitalWrite(targetPin, HIGH);   // sets the LED on
    delay(blinkRate);                     // waits for a blinkRate milliseconds
    digitalWrite(targetPin, LOW);    // sets the LED off
    delay(blinkRate);
  }
}