Serial read_problem

Projects Programming
1

Hello,
I am going to use serial port and read different numbers, but this code only works for numbers below 10 (for example: '5')

void setup() {
// initialize serial communication:
Serial.begin(9600);
int inByte = 0;
}
void loop() {

if (Serial.available()>0) {
int inByte = Serial.read();
if (inByte == 30) {
Serial.print("Hello");
}
}
}

2

Do you have a question?

Please remember to use code tags when posting code

3

Hints:

A character are things like A, 1, and 3 and can be stored in ONE byte.

Words are like 10 and APPLE which CANNOT be stored in one byte.

To make a word you'd want to combine all your characters.

There is some serial basics write ups on this site, use search, that you'd want to read up on.

serial basics <<< a link!! clicky clicky. A link to serial basics thingy.

4

The name 'inByte' seems to imply that the variable should be a 'byte' instead of an 'int'. I would make it a 'char' instead, since that is the natural type for a variable that holds a character.

void setup()
{
  // initialize serial communication:
  Serial.begin(9600);
  Serial.println();
  Serial.println("Started.");
}

void loop()
{
  if (Serial.available() > 0)
  {
    char inChar = Serial.read();

    if (inChar == '0')
    {
      Serial.println("Hello");
    }
  }
}
6

Yes, the code doesn't work, I need to send "30" but this code works only for numbers below 9.

7

Thank you very much.
But I need to send other numbers, 10, 11 and so on

8

Won't look at the how to do the serial thingy. <<<< That's the easy button.

Here is a function that receives bytes from the serial and forms it into words.

void fReceiveSerial_LIDAR( void * parameters  )
{
  bool BeginSentence = false;
  char OneChar;
  char *str;
  str = (char *)ps_calloc(300, sizeof(char) ); // put str buffer into PSRAM
  // log_i("Free PSRAM before String: %d", ESP.getFreePsram());
  for ( ;; )
  {
    EventBits_t xbit = xEventGroupWaitBits (eg, evtReceiveSerial_LIDAR, pdTRUE, pdTRUE, portMAX_DELAY);
    if ( LIDARSerial.available() >= 1 )
    {
      while ( LIDARSerial.available() )
      {
        OneChar = LIDARSerial.read();
        if ( BeginSentence )
        {
          if ( OneChar == '>')
          {
            if ( xSemaphoreTake( sema_ParseLIDAR_ReceivedSerial, xSemaphoreTicksToWait10 ) == pdTRUE )
            {
               xQueueOverwrite( xQ_LIDAR_Display_INFO, ( void * ) &str );
              xEventGroupSetBits( eg, evtParseLIDAR_ReceivedSerial );
              //
            }
            BeginSentence = false;
            break;
          }
          strncat( str, &OneChar, 1 );
        }
        else
        {
          if ( OneChar == '<' )
          {
            strcpy( str, ""); // clear string buffer
            BeginSentence = true; // found beginning of sentence
          }
        }
      } //  while ( LIDARSerial.available() )
    } //if ( LIDARSerial.available() >= 1 )
    xSemaphoreGive( sema_ReceiveSerial_LIDAR );
    //        log_i( "fReceiveSerial_LIDAR " );
    //        log_i(uxTaskGetStackHighWaterMark( NULL ));
  }
  free(str);
  vTaskDelete( NULL );
} //void fParseSerial( void * parameters  )
9

"Serial" has a method ".parseInt()" for when you are expecting a multi-digit number:

void loop()
{
  if (Serial.available())  // means "if Serial.available() is not equal to zero"
  {
    int inNumber = Serial.parseInt();
    if (inNumber == 30)
    {
      Serial.print("Hello");
    }
  }
}
10

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