No matching function for call to 'BlynkStream::begin(char [33], HardwareSerial&)'

hi there, i amcompilng following code and having error ===> “no matching function for call to 'BlynkStream::begin(char [33], HardwareSerial&)”

#include <BlynkSimpleStream.h>
int sensorPin = A0;    
int ledPin = 9;     
int sensorValue = 1;
 char auth[] = "SZN5JK5GVRNDfFOVo4T0UmPRmX76Ar";
 void setup()
   pinMode(ledPin, OUTPUT);  
   Blynk.begin(auth, Serial);
   pinMode(11, OUTPUT);
   pinMode(12, OUTPUT);
   pinMode(13, OUTPUT);
 BLYNK_WRITE(V1) //Button Widget is writing to pin V1
  int pinData = param.asInt(); 
    digitalWrite(11, HIGH);
    digitalWrite(11, LOW);
 void loop()
  sensorValue = analogRead(sensorPin);
  // turn the ledPin on
  if (sensorValue<=450)
    digitalWrite(ledPin, HIGH);
  // stop the program for <sensorValue> milliseconds:
    digitalWrite(ledPin, LOW);
  // stop the program for for <sensorValue> milliseconds:

Please edit your post and add triple backticks ( ``` ) before and after your whole sketch.


Now you should provide more details like blynk IOT or legacy, library version, hardware type etc…

It’s blynk legacy and the latest version of library, hardware is esp32.

I’d always recommend using library version 0.6.1 with Legacy.

The BlynkSimpleStream library is intended for use when the device connects via the serial port, with a PC that’s running the Blynk connection script.
I would imagine that you’d be using the ESP32’s WiFi capability rather than a serial connection?


1 Like

downgrading the library to version 0.6.1 should fix this issue.
also, you should read this

1 Like

Try changing the order inside the Blynk.begin command,

From -----> Blynk.begin(auth, Serial);

To ----------> Blynk.begin(Serial, auth);

I faced the same issue and once I changed the order it worked out for me.