check if serial-input contains string

Projects Programming
1

hey, i think the following is an easy question for experienced arduino-users, but i'm failing for hours now and coulnt find any help.

i programmed a little app in processing which should communicate with the arduino via the serial port. in processing i simply write a string using

println("newrfid");

... which seems to work - i can see that also in the serial monitor in arduino. but i'm not able to read this specific part of the input-string but only can output the whole serial input.

this is my code:

   if(Serial.available() > 0){
     char letter = Serial.read();
     if(letter == 'newrfid'){
       soundInit();
     }
   }

it's compiling without any errors, but its just not working =(

i'm searching for a function which allows me to search the whole input-string for a specific part... i tried indexOf and equals without success.

any help would be appreciated

2

i use the following code for creating a string out of the serial.read-input

void serialEvent() {
  while (Serial.available()) {
    // get the new byte:
    char inChar = (char)Serial.read(); 
    // add it to the inputString:
    inputString += inChar;
    // if the incoming character is a newline, set a flag
    // so the main loop can do something about it:
    if (inChar == '\n') {
      stringComplete = true;
    } 
  }
}

and this is how my loop looks like

void loop(){
   readrfid();
   
   if (stringComplete) {
      Serial.println(inputString);
        if (inputString.substring(0)=="newrfid") {
          soundInit();
        }
      //clear the string:
      inputString = "";
      stringComplete = false;
    }
  
}

its not working :frowning:

3 
        if (inputString.substring(0)=="newrfid")

How many characters does inputString.substring(0) return ?

4

cant tell, because while processing is running i cant open the serial monitor in arduino, but need the processing app to write into the serial...

5

It wasn't that sort of question.

The answer to the question is in the code - there is no need to see anything in the serial monitor.

...R

6 
     if(letter == 'newrfid'){

Which ONE key did you press to get that ONE letter in the single quotes?

Do you really expect a string of letters to match the one letter you read from the serial port? I didn't think so.

7

i'm searching for a function which allows me to search the whole input-string for a specific part... i tried indexOf and equals without success.

You might try the below comma , delimited method.

//zoomkat 9-9-10 simple delimited ',' string parse
//from serial port input (via serial monitor)
//and print result out serial port


String readString; // = String(100);

void setup() {
  Serial.begin(9600);
}

void loop() {
  while (Serial.available()) {
    delay(10);  //small delay to allow input buffer to fill
    if (Serial.available() >0) {
      char c = Serial.read();  //gets one byte from serial buffer
      if (c == ',') {
        break;
      }  //breaks out of capture loop to print readstring
      readString += c;
    } //makes the string readString
  }

  if (readString.length() >0) {
    Serial.println(readString); //prints string to serial port out

    if(readString.indexOf("woohoo") >=0) {
      Serial.println("I found woohoo!"); 
    }

    readString=""; //clears variable for new input
  }
}