Serial write Arduino

Question

I have a problem with the function Serial.write() I was testing my connection with python, and I can send numbers, words, or letters, but when I try to send the value of variable the function Serial. write gives me an error. So could you tell me what is happening?

#define Pin A1

void setup() {

    pinMode(Pin, INPUT); 

    Serial.begin(9600); 

}

void loop() {

    String a = String(13);

    Serial.write(a);   

}

ERROR

C:\Users\ADMIN\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.2\cores\arduino/Print.h:52:12: note:   no known conversion for argument 1 from 'String' to 'const char*'

exit status 1

No matching function for call to 'HardwareSerial:: write(String&)'

Answer 1

If you want to send string means you directly enter the string in serial.write(). while giving the string directly into the serial.write() then it will take that string as const char* not as a string type

Serial.write("hello");

Else you cannot send the string as directly in serial.write.you can use serial.print.use char array to send

Serial.write(MyString, sizeof(MyString));

Else you can send every char

void writeString(String stringData) { // Used to serially push out a String with Serial.write()

  for (int i = 0; i < stringData.length(); i++)

  {

    Serial.write(stringData[i]);   // Push each char 1 by 1 on each loop pass

  }

}// end writeString

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