LED Blinking Patterns

Solving Approach

To solve this task, we will create a program that cycles through five distinct LED patterns controlled by a single push-button.

• Hardware Setup: We will use an Arduino UNO, four LEDs, one push-button, and five resistors. The four LEDs will act as our outputs, and the single push-button will serve as our input.
• Wiring: The four LEDs will be connected to separate digital output pins on the Arduino, each with a current-limiting resistor to ground. For the push-button, we will use the Arduino's internal pull-up resistor to simplify the wiring, connecting the button between a digital input pin and ground. This means a button press will register as a LOW signal.
• Software Logic: The code will use a counter variable to keep track of the current pattern, from 1 to 5.
  1. We will continuously monitor the push-button's state.
  2. When a button press is detected, we will increment the counter. We'll use a debouncing technique to prevent the button from registering multiple presses from a single click.
  3. A switch...case statement will be used to select the correct LED pattern based on the counter's value.
  4. The digitalWrite() function will then be used to turn the appropriate LEDs on or off to display the current pattern.
  5. Once the counter reaches the end of the patterns, it will reset to 1 to loop back to the first pattern.

Code

/*Paste your code here*/

const int Button = 10;
const int Led1 = 6;
const int Led2 = 5;
const int Led3 = 4;
const int Led4 = 3;

int pattern = 1;             
int lastReading = HIGH;        
int buttonState = HIGH;      
unsigned long lastDebounce = 0;
const unsigned long debounceDelay = 50;

unsigned long lastPatternMillis = 0;
bool phase = true;            
int stepIndex = 0;            

void setup() {
pinMode(Button, INPUT_PULLUP);
pinMode(Led1, OUTPUT);
pinMode(Led2, OUTPUT);
pinMode(Led3, OUTPUT);
pinMode(Led4, OUTPUT);

lastPatternMillis = millis();
applyPatternOutputs();     
}

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

int reading = digitalRead(Button);
if (reading != lastReading) lastDebounce = now;

if (now - lastDebounce > debounceDelay) {
if (reading != buttonState) {
buttonState = reading;
if (buttonState == LOW) {          
pattern++;
if (pattern > 5) pattern = 1;     
phase = true;                    
stepIndex = 0;
lastPatternMillis = now;
applyPatternOutputs();           
}
}
}
lastReading = reading;

unsigned long interval;
if (pattern == 1) {               
interval = (phase ? 1000UL : 500UL);
} else {
interval = 500UL;               
}


if (now - lastPatternMillis >= interval) {
lastPatternMillis = now;

if (pattern == 3) {

stepIndex++;
if (stepIndex > 3) stepIndex = 0;
applyPatternOutputs();
} else {

phase = !phase;
applyPatternOutputs();
}
}
}


void applyPatternOutputs() {
  
digitalWrite(Led1, LOW);
digitalWrite(Led2, LOW);
digitalWrite(Led3, LOW);
digitalWrite(Led4, LOW);

if (pattern == 1) {
if (phase) {
digitalWrite(Led1, HIGH);
digitalWrite(Led2, HIGH);
digitalWrite(Led3, HIGH);
digitalWrite(Led4, HIGH);
} 
}

else if (pattern == 2) {
if (phase) {
digitalWrite(Led1, HIGH);
digitalWrite(Led3, HIGH);
} else {
digitalWrite(Led2, HIGH);
digitalWrite(Led4, HIGH);
}

}
else if (pattern == 3) {
if (stepIndex == 0) digitalWrite(Led1, HIGH);
else if (stepIndex == 1) digitalWrite(Led2, HIGH);
else if (stepIndex == 2) digitalWrite(Led3, HIGH);
else if (stepIndex == 3) digitalWrite(Led4, HIGH);
}

else if (pattern == 4) {
if (phase) {
digitalWrite(Led1, HIGH);
digitalWrite(Led2, HIGH);
} else {
digitalWrite(Led3, HIGH);
digitalWrite(Led4, HIGH);
}
}

else if (pattern == 5) {

if (phase) {
digitalWrite(Led1, HIGH);
digitalWrite(Led4, HIGH);
} else {
digitalWrite(Led2, HIGH);
digitalWrite(Led3, HIGH);
}
}
}

Output

Video

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