Lesson 4 of 5

Fade with LEDC PWM

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// LEDC makes the PWM: attach it to the pin, then write a duty const int LED_PIN = 23; const int FREQ_HZ = 5000; const int RESOLUTION = 8; void setup() { Serial.begin(115200); ledcAttach(LED_PIN, FREQ_HZ, RESOLUTION); Serial.println("LEDC fade on GPIO23"); } void loop() { int maxDuty = (1 << RESOLUTION) - 1; for (int i = 0; i <= 50; i++) { ledcWrite(LED_PIN, maxDuty * i / 50); delay(20); } for (int i = 50; i >= 0; i--) { ledcWrite(LED_PIN, maxDuty * i / 50); delay(20); } }

Stopped · Your code isn't running yet. Until you press Run, the board runs the program already on it.

Nothing printed yet. Press Run.

The ESP32 has no analogWrite timers like an Uno; it has the LEDC peripheral. Attach it to GPIO23, then ramp the duty up and down for a smooth fade.

The current arduino-esp32 3.x LEDC API
Frequency and resolution are yours to change
Watch for the 80 MHz frequency × resolution limit

Pin	Connects to	What it does
`GPIO23`	220 Ω resistor, then the LED's anode	PWM output from the LEDC peripheral
`GND`	LED cathode	Return path

Wire it in

Sensors and actuators this board drives, with the real connections.

All 8 parts on the ESP32-DevKitC V4 page

Fade with LEDC PWM

Try it yourself

Serial monitor

Checks

Break it

Parameters

Wire it in

Fade with LEDC PWM

Try it yourself

Serial monitor

Checks

Break it

Parameters

Wire it in