Arduino Heartbeat File Monitor - blinks a binary code in response to blink_media_activity.pl

blink_perl_improved

/*
 * Heartbeat File Meter
 * by truckershitch
 *
 * Added blink limit to prevent runaway blinking on boot
 * Cleaned up loop and variables
 * 11/22/17
 * 
 * based on
 * Numerical Echo
 * by Martijn
 * 22 Nov 2008

 * Listen to serial input coming from the computer. If the input is not 0,
 * pulse that number of heartbeats.
 */

const int blinkOn = 250;  // timeframe that the LED is switched ON
const int ASC_ZERO = 48; // ASCII for 0 (zero)

void blink_led(int value) {
  int count = value - ASC_ZERO; // number of beats
  if (count <= 15) { // validate input
    for (int i = 1; i <= count; i++) {
      digitalWrite(LED_BUILTIN, HIGH);    // LED on
      delay(blinkOn);
      digitalWrite(LED_BUILTIN, LOW);    // LED off
      delay(blinkOn);
    }
    digitalWrite(LED_BUILTIN, LOW); // LED off
    delay(4 * blinkOn); // LED off - pausing here
  }
}

void setup() {
  Serial.begin(19200);
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  if (Serial.available()) {
    int input = Serial.read();    // listen for input
    if (input > ASC_ZERO) {
      blink_led(input);
    }
  }
}