In this tutorial I will show you how to make
LED control using
Arduino with PWM. For dimming control I will use an
encoder. So it will also be a tutorial on how to use the
encoder in Arduino projects. In the project I use 6 LEDs each 10W, as a power source I will use a 14.4V battery from a cordless drill. In this guide will use my previous project
DIY mega head flashlight with 6x10W LEDs
bool btn = digitalRead(BTN_PIN); //Read state of encoder switch.
if( btn!=last_button_state && current_time - button_time > 100 ){ //If the state is different from the previous one and since last state change has been at least 100ms.
if( btn==LOW && last_button_state ){ //Detect the transitions from HIGH to LOW
if( led_power==255 ){
led_power = 0;
}else{
led_power = 255;
}
analogWrite(LED_PWM_PIN, led_power);
}
last_button_state = btn;
button_time = current_time;
}
This code fragment is responsible for handling encoder. It recognizes whether the encoder
if( current_time - loop_time >= 5 ){
encoder_A = digitalRead(EN_PIN_A); //Read encoder pin A
encoder_B = digitalRead(EN_PIN_B); //Read encoder pin B
if( !encoder_A && last_encoder_A ){
if( encoder_B ){
Serial.println( "L: " + String(led_power) );
led_power = led_power - power_step;
}else{
Serial.println( "R: " + String(led_power) );
led_power = led_power + power_step;
}
All dimmer software.
#define LED_PIN 13
#define LED_PWM_PIN 11
#define EN_PIN_A 12
#define EN_PIN_B 8
#define BTN_PIN 4
unsigned char encoder_A;
unsigned char encoder_B;
unsigned char last_encoder_A;
unsigned char last_encoder_B;
int led_power = 0;
int power_step = 1;
long loop_time;
long button_time;
bool last_button_state;
void setup() {
pinMode(LED_PIN, OUTPUT);
pinMode(EN_PIN_A, INPUT_PULLUP);
pinMode(EN_PIN_B, INPUT_PULLUP);
pinMode(BTN_PIN, INPUT_PULLUP);
analogWrite(LED_PWM_PIN, 0);
Serial.begin( 115200 );
Serial.println( "START" );
}
void loop() {
long current_time = millis(); //millis() - Returns the number of milliseconds since the Arduino board began running the current program.
bool btn = digitalRead(BTN_PIN); //Read state of encoder switch.
if( btn!=last_button_state && current_time - button_time > 100 ){ //If the state is different from the previous one and since last state change has been at least 100ms.
if( btn==LOW && last_button_state ){ //Detect the transitions from HIGH to LOW
if( led_power==255 ){
led_power = 0;
}else{
led_power = 255;
}
analogWrite(LED_PWM_PIN, led_power);
}
last_button_state = btn;
button_time = current_time;
}
if( current_time - loop_time >= 5 ){
encoder_A = digitalRead(EN_PIN_A); //Read encoder pin A
encoder_B = digitalRead(EN_PIN_B); //Read encoder pin B
if( !encoder_A && last_encoder_A ){
if( encoder_B ){
Serial.println( "L: " + String(led_power) );
led_power = led_power - power_step;
}else{
Serial.println( "R: " + String(led_power) );
led_power = led_power + power_step;
}
if( led_power < 0 ) led_power=0;
if( led_power >= 255 ) led_power=255;
if( led_power >= 0 && led_power <=10 ){
power_step = 1;
}else if( led_power > 10 && led_power <=20 ){
power_step = 2;
}else if( led_power > 20 && led_power <=30 ){
power_step = 5;
}else if( led_power > 30 ){
power_step = 10;
}
analogWrite(LED_PWM_PIN, led_power);
}
last_encoder_A = encoder_A;
last_encoder_B = encoder_B;
loop_time = current_time;
}
}
