Reading the serial port

Projects Programming
1

I want to pass commands to the arduino from a pc and then get the arduino to perform actions based on the command

i have written some code but it sometimes seems to not work

here is an example

 while (Serial.available()) 
 {
    InChr= Serial.read();  //gets one byte from serial buffer
    if (InChr == '%') 
    {
      break;
    }  //breaks out of capture loop to print readstring
    InStr += InChr ; 
 }  
 
 if (InStr == "Reset") 
  {
    Serial.println("Reset Counter = 0");
       N = 0 ;
       InStr = "" ;
  }
  
  if (InStr.substring(0,5) == "Start") 
  {  
    //InStr = InStr.trim() ;
    InStr = InStr.substring(5,(InStr.length() + 1 )) ;
    Serial.println(InStr) ;
    //-------------------
    char buff[32]="";
    InStr.toCharArray(buff,sizeof(buff));
    buff[ sizeof(buff) / sizeof(buff[0]) - 1 ]='\0'; // I always like to null terminate strings just in case
    TargetSpeed =  atof(buff);    
    //-------------------
    Serial.print("Start Process - ") ;
    InStr = "" ;
    LoadOn = false ;
    ManLoad = false ;
  }

I send it a command for example "Start%"

it seems to work first time you send it always, but sometimes it does nothing

is there some standard tried and trusted code for reading the serial port i can use ?

2

t seems to work first time you send it always, but sometimes it does nothing

What do your debug prints tell you (and us) what is happening?

3

is there some standard tried and trusted code for reading the serial port i can use ?

Sure. Serial.read(). It's the only code you can use. How you use it is critical. The code snippet you posted looks good. The code you didn't post is obviously where the problem occurs. Perhaps you are not reinitializing InStr at appropriate points.