How to control the onboard LEDC of ESP32-S2

[sangyuxiaowu]

I have a development version of the ESP32 development board brushed FEATHER_S2 firmware.
information:
https://www.waveshare.com/wiki/ESP32-S2-Pico
schematic diagram:
https://www.waveshare.net/w/upload/3/35/ESP32-S2-Pico_Sch.pdf

I want to control the onboard LEDC. I tried many ways, but I can only make it always on, and I can't control it.

The following is provided Arduino example：

/*
 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            9

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);
}

this is my code:

using nanoFramework.Hardware.Esp32;
using System;
using System.Device.Pwm;
using System.Diagnostics;
using System.Threading;

namespace BlinkBoardLed
{
    public class Program
    {


        public static void Main()
        {
            Configuration.SetPinFunction(9, DeviceFunction.PWM1);
            PwmChannel led = PwmChannel.CreateFromPin(9, 5000, 0.4);
            led.Start();

            bool goingUp = true;
            float dutyCycle = .00f;

            while (true)
            {
                if (goingUp)
                {
                    // slowly increase light intensity
                    dutyCycle += 0.05f;

                    // change direction if reaching maximum duty cycle (100%)
                    if (dutyCycle > .95)
                        goingUp = !goingUp;
                }
                else
                {
                    // slowly decrease light intensity
                    dutyCycle -= 0.05f;

                    // change direction if reaching minimum duty cycle (0%)
                    if (dutyCycle < 0.10)
                        goingUp = !goingUp;//break;
                }

                // update duty cycle
                led.DutyCycle = dutyCycle;
                Debug.WriteLine(dutyCycle.ToString());
                Thread.Sleep(500);
            }
            led.DutyCycle = .00f;

            led.Stop();
        }
    }
}

[Ellerbach]

From the data sheet you sent, the power led will always be on:

It is not controllable by software.

[sangyuxiaowu]

Thank you for your reply, I found out that the control uses ws2812 based on other cases provided, so I found this https://github.com/nanoframework/nf-Community-Contributions/tree/master/drivers/ESP32-WS2812 and found that the control can be realized

[Ellerbach]

Sure, controlling the WS2812 led is a different story :-) In that case, you better have to use the nuget: https://github.com/nanoframework/nanoFramework.IoT.Device/blob/develop/devices/Ws28xx.Esp32