E.G. In this ESP32 example sketch
What is the point behind multiple channels associated with a digital pin?
ledcSetup(LEDC_CHANNEL_0, LEDC_BASE_FREQ, LEDC_TIMER_13_BIT);
ledcAttachPin(LED_PIN, LEDC_CHANNEL_0);
Code: Select all
/*
LEDC Software Fade
This example shows how to software fade LED
using the ledcWrite function.
Code adapted from original Arduino Fade example:
https://www.arduino.cc/en/Tutorial/Fade
This example code is in the public domain.
*/
// use first channel of 16 channels (started from zero)
#define LEDC_CHANNEL_0 0
// use 13 bit precission for LEDC timer
#define LEDC_TIMER_13_BIT 13
// use 5000 Hz as a LEDC base frequency
#define LEDC_BASE_FREQ 5000
// fade LED PIN (replace with LED_BUILTIN constant for built-in LED)
#define LED_PIN 5
int brightness = 0; // how bright the LED is
int fadeAmount = 5; // how many points to fade the LED by
// Arduino like analogWrite
// value has to be between 0 and valueMax
void ledcAnalogWrite(uint8_t channel, uint32_t value, uint32_t valueMax = 255) {
// calculate duty, 8191 from 2 ^ 13 - 1
uint32_t duty = (8191 / valueMax) * min(value, valueMax);
// write duty to LEDC
ledcWrite(channel, duty);
}
void setup() {
// Setup timer and attach timer to a led pin
ledcSetup(LEDC_CHANNEL_0, LEDC_BASE_FREQ, LEDC_TIMER_13_BIT);
ledcAttachPin(LED_PIN, LEDC_CHANNEL_0);
}
void loop() {
// set the brightness on LEDC channel 0
ledcAnalogWrite(LEDC_CHANNEL_0, brightness);
// change the brightness for next time through the loop:
brightness = brightness + fadeAmount;
// reverse the direction of the fading at the ends of the fade:
if (brightness <= 0 || brightness >= 255) {
fadeAmount = -fadeAmount;
}
// wait for 30 milliseconds to see the dimming effect
delay(30);
}