LED Blinking Patterns

Solving Approach

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Code

/*Paste your code here*/
const int led_pins[] = { 2, 3, 4, 5 };            // LEDs connected to pins
const int switch_pin = 12;                        // Pin for the switch

// Arrays related to LED Patterns
const int pattern_lengths[] = { 2, 2, 4, 2, 2 };  
const int patterns[][4][4] = {  
    { { 1, 1, 1, 1 }, { 0, 0, 0, 0 } },                                      // Pattern 0
    { { 1, 0, 1, 0 }, { 0, 1, 0, 1 } },                                      // Pattern 1
    { { 1, 0, 0, 0 }, { 0, 1, 0, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 1 } },      // Pattern 2
    { { 1, 1, 0, 0 }, { 0, 0, 1, 1 } },                                      // Pattern 3
    { { 1, 0, 0, 1 }, { 0, 1, 1, 0 } }                                       // Pattern 4
};

unsigned int flag_check = 1;          // Controls the execution of the current pattern
int pattern_index = 0;                // Current pattern index
unsigned long debounce_delay = 50;    // Debounce delay in milliseconds
int last_button_state = 1;            // Previous button state (1: not pressed, 0: pressed)
int current_button_state = 1;         // Current button state
unsigned long last_debounce_time = 0; // Timestamp of the last button state change

void setup() {
   
    for (int i = 0; i < 4; i++) {
        pinMode(led_pins[i], OUTPUT);
    }

    pinMode(switch_pin, INPUT_PULLUP);    
}

void loop() {
    // Execute the selected pattern
    while (flag_check) {
        // Iterate through each step of the current pattern
        for (int j = 0; j < pattern_lengths[pattern_index]; j++) {
            set_leds(patterns[pattern_index][j]);                     // Set LEDs for the current step
            flag_check = delay_with_button_check(500);                // Wait with button check
            if (!flag_check) break;                                   // Exit if the button is pressed
        }
        if (!flag_check) break;                                       // Exit the pattern loop if the button is pressed
    }
    flag_check = 1;                                                   // Reset flag after pattern completion
}


 // Checks if the button is pressed and debounced.
 
bool is_debounced_press(int button_pin) {
    int reading = digitalRead(button_pin); 

    // If the button state has changed, reset the debounce timer
    if (reading != last_button_state) {
        last_debounce_time = millis();
    }
    last_button_state = reading; 
    // If the button state is stable for more than 50 msec the debounce delay, update the state.
    if ((millis() - last_debounce_time) > debounce_delay) {
        if (reading != current_button_state) {
            current_button_state = reading;
            
            // Return true if the button is pressed (LOW state)
            if (current_button_state == 0) {
                return true;  // valid press detected
            }
        }
    }
    return false;                // No valid press detected
}


// Implements a delay while checking for button press. 
 
bool delay_with_button_check(long delay_duration) {
    long delay_start_time = millis(); // Record the start time of the delay
    while ((millis() - delay_start_time) < delay_duration) {
        if (is_debounced_press(switch_pin)) {
            pattern_index = (pattern_index + 1) % 5; // Cycle to the next pattern
            return false;                            // Exit delay early
        }
    }
    return true; // Continue executing the pattern
}

// Set the states of the LEDs
void set_leds(const int states[]) {
  for (int i = 0; i < 4; i++) {
    digitalWrite(led_pins[i], states[i]);
  }
}

Output

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