Axiometa Spark

/*
Example Code for Axiometa Spark
===================================

Description: This example demonstrates the functionality of the Axiometa Spark microcontroller,
featuring LED control, PWM fading, and an interrupt-driven button handler.

Features:
– Reads ambient light using an LDR and turns on/off an LED based on light levels.
– Smoothly fades a PWM-controlled LED.
– Detects button press using an interrupt and outputs a message to the Serial Monitor.

Pin Configuration:
– ACT_LED (Pin 13): Indicates low-light detection status.
– PWM_LED (Pin 10): PWM fading LED.
– BUTTON_PIN (Pin 2): Button for interrupt handling.
– LDR_PIN (Analog Pin A3): Light-dependent resistor for ambient light detection.

Author: Povilas Dumcius
Last Updated: 2024 January 11th
License: Open-source, for educational and prototyping purposes.
*/

#define ACT_LED 13    // Activity LED
#define PWM_LED 10    // PWM Capable LED
#define BUTTON_PIN 2  // Button pin
#define LDR_PIN A3    // LDR pin

void setup() {
  // Initialize Serial communication at 9600 baud
  Serial.begin(9600);
  // Set pin modes
  pinMode(ACT_LED, OUTPUT);    // Configure ACT_LED pin as output
  pinMode(PWM_LED, OUTPUT);    // Configure PWM_LED pin as output
  pinMode(BUTTON_PIN, INPUT);  // Configure BUTTON_PIN as input
  // Attach an interrupt to the button pin
  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), interruptHandler, FALLING);
  // Perform startup LED blinking sequence
  startupLED();
}

void loop() {
  lightDetection();  // Monitor light levels and control ACT_LED
  PWM();             // Perform PWM fading for PWM_LED
}

// Function to blink ACT_LED during startup
void startupLED() {
  for (unsigned int i = 0; i < 5; i++) {
    digitalWrite(ACT_LED, HIGH);  // Turn on LED
    delay(100);                   // Wait for 100 ms
    digitalWrite(ACT_LED, LOW);   // Turn off LED
    delay(100);                   // Wait for 100 ms
  }
}

// Function to detect light levels and control ACT_LED
void lightDetection() {
  int dataLDR = analogRead(LDR_PIN);  // Read LDR value
  if (dataLDR > 400) {                // Check if light is above threshold
    digitalWrite(ACT_LED, HIGH);      // Turn on ACT_LED
  } else {
    digitalWrite(ACT_LED, LOW);  // Turn off ACT_LED
  }
}

// Function to perform PWM fading on PWM_LED
void PWM() {
  // Fade in
  for (int fadeValue = 0; fadeValue <= 255; fadeValue += 15) {
    analogWrite(PWM_LED, fadeValue);  // Set PWM brightness
    delay(30);                        // Wait for 30 ms
  }
  // Fade out
  for (int fadeValue = 255; fadeValue >= 0; fadeValue -= 15) {
    analogWrite(PWM_LED, fadeValue);  // Set PWM brightness
    delay(30);                        // Wait for 30 ms
  }
}

// Interrupt Service Routine for BUTTON_PIN
void interruptHandler() {
  Serial.println("Hello from Axiometa Spark – you pressed a button");
}