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Blynk App Virtual Pin Read


#1

I am using ESP32 with the PWM led. I want to control led by Blynk slider widget. I am reading reading V1 value. How to use int pinValue from V1 in loop function for ledcWrite

char auth[] = "YourAuthToken";

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "Network";
char pass[] = "password";

public BLYNK_WRITE(V1)
{
  int pinValue = param.asInt(); // assigning incoming value from pin V1 to a variable
  return 0;
}

void setup()
{
  // Debug console
  Serial.begin(9600);

  Blynk.begin(auth, ssid, pass);
  ledcSetup(0,5000,8);
  ledcAttachPin(22,0);
}

void loop()
{
  Blynk.run();
  ledcWrite(0, value);
}

#2

Declare a global variable
Assign value to this variable in Blynk Read
Write it to led pin inside of Blynk Read


#3

This might help


#4

Thanks for your help.
So for my red led, code will be like this

int rrr,

  //===== RGB LED pin setup for ESP32 =====
  ledcSetup(2, 5000, 8); // For RGB-Red - channel 2, 5000 Hz, 8-bit width
  ledcAttachPin(25, 2);   // For RGB-Red - GPIO 25 assigned to channel 2

BLYNK_WRITE(V4) { // START Blynk Function
  rrr = param[0].asInt();
  RGBprocess();
}

void RGBprocess() { 
ledcWrite(2, 256 - rrr);

  // zeRGBa pin to #HEX conversion
  String strRED = String(rrr, HEX);  // Convert RED DEC to HEX
  if (rrr < 16) {
    strRED = String("0" + strRED);  // Buffer with 0 if required
  }  // END if
}  // END Arduino Function

void loop() {
  Blynk.run();
}

#5

Thanks for your help. I want to get value from app for the slider in my arduino code and want to use it in ledcWrite function call in loop function.


#6

@davidkhan My example was a bit more complex becasue it was using the zeRGBa and mapping to HEX for changing widget colours

But if all you want to do is adjust the PWM range of a single LED with a slider on the ESP32 then it can be as simple as this (with the required ESP channel and frequency settings of course)…

BLYNK_WRITE(vPin)
ledcWrite(ledChannel, param.asInt());
}

Using the 8-bit range, you set your sliders MIN-MAX to 0-255, or perhaps 255-0 for inversely driven pins… adjust the range for higher bit rates if wanted, e.g. 10bit and 0-1024 or 12 bit 0-4096 for servos, etc.


#7

Thanks Gunner for your help. Now controlling PWM on esp32 with Blynk slider.