58 lines
1.5 KiB
C++
58 lines
1.5 KiB
C++
/*
|
|
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);
|
|
}
|