Receiving weird characters in Serial monitor..

Projects Programming
1

i try to read data from serial monitor using the code

#define max_size 40
char data_buffer[max_size];
char question_1[] = "please enter command with value";
void setup(){
Serial.begin(9600);
}//end of setup() function

void loop(){
  serial_question(question_1);
  serial_check();
  serial_output();
}//end of loop() function

void serial_question(char* question){
  Serial.println(question);
}//end of serial_question() function

void serial_check(){
    while(!Serial.available()){
  //wait until user enters the data
  }//end of while
 while(!received()){
   //wait until full message is received
   //Serial.println("received");
 }//end of while
}//end of serial_check() function

boolean received(){

 static  byte index = 0;
 char input = Serial.read();
if(input == '\r'){
data_buffer[index] = 0;
index =0;
return true;
}
data_buffer[index] = input;
index = index + 1;
return false;
//}//end of received() function


void serial_output(){
Serial.println(data_buffer);
}//end of serial_output() function

But as usual i failed to do so..
and after struggling sometime i got the mistakes in my code..
and right one is

#define max_size 40
char data_buffer[max_size];
char question_1[] = "please enter command with value";
void setup(){
Serial.begin(9600);
}//end of setup() function

void loop(){
  serial_question(question_1);
  serial_check();
  serial_output();
}//end of loop() function

void serial_question(char* question){
  Serial.println(question);
}//end of serial_question() function

void serial_check(){
    while(!Serial.available()){
  //wait until user enters the data
  }//end of while
 while(!received()){
   //wait until full message is received
   //Serial.println("received");
 }//end of while
}//end of serial_check() function

boolean received(){
 if(Serial.available()){
 static  byte index = 0;
 char input = Serial.read();
if(input == '\r'){
data_buffer[index] = 0;
index =0;
return true;
}
data_buffer[index] = input;
index = index + 1;
return false;
}//end of received() function
}

void serial_output(){
Serial.println(data_buffer);
}//end of serial_output() function

and my real question is i got a weird character in serial monitor when i used first code it is like y with two dots above it..
what is that character?

parsing_1.JPG

2

The first program above does not compile, presumably because of

//}//end of received() function

Is it actually the program that you were running when you got the strange output ?

3

Hi ani -

Check if your monitor is set to the same baudrate, as in your serial.begin(9600).

You can find it in the lower right corner of the monitor window.

4

and my real question is i got a weird character in serial monitor when i used first code it is like y with two dots above it..
what is that character?

The y with 2 dots is what appears in the Serial Monitor application, or other application that expects ASCII data when you try to print -1 (or 255), which is what Serial.read() returns when there is nothing to read.

5

Have a look at the simple reliable examples for receiving data in serial input basics. The 2nd example can probably work unchanged with your question function.

...R

6

PaulS:
The y with 2 dots is what appears in the Serial Monitor application, or other application that expects ASCII data when you try to print -1 (or 255), which is what Serial.read() returns when there is nothing to read.

thanks for it.