Serial Print Byte - Only changed values

[codyk27]

Hello,

How would I go about changing this code around to only show the n0.val numerical change instead of printing each byte individually. Array maybe?

Currently my serial monitor looks like:

Attached below is the code.

(Also I'm using a Audiowell UM0034)
For reference on how this device uses its UART communication (https://www.unitronic.de/wp-content/uploads/productimports/23509_DB_UM0034.pdf)

const unsigned int MAX_MESSAGE_LENGTH = 12;
static char message[MAX_MESSAGE_LENGTH];
static int message_pos = 0;

void setup() {
 Serial.begin(9600);
    //Create a place to hold the incoming message

}

void loop() {

 //Check to see if anything is available in the serial receive buffer
 while (Serial.available() > 0)
 {

   char inByte = Serial.read();


   if ( inByte != '\n' && (message_pos < MAX_MESSAGE_LENGTH - 1) )
   {
     message[message_pos] = inByte;
     message_pos++;
   }
   else
   {
     message[message_pos] = '\0';
     
     Serial.println(message);
     message_pos = 0;
   }
 }
}

[gcjr]

you could use readBytesUntil() to read a complete line terminated by a '\n'.

you could have a 2nd string and compare, strcmp(), the line just read to the 2nd string, print it if different and then strcpy() the received line to the 2nd string

[codyk27]

Would you mind fitting your example into my code? I'm having a hard time with the 2nd string. I've been chasing my tail on this problem for a week now. This is the second sensor I've tried. The single transducer version has too big of a blind spot. This one will work great if I can get the value to print correctly

[Whandall]

@codyk27

if ( inByte != '\n' && (message_pos < MAX_MESSAGE_LENGTH - 1) )

From the message format, that should be more like:

if ( inByte != 0xFF && (message_pos < MAX_MESSAGE_LENGTH - 1) )

[gcjr]

const int MsgLen = 50;
char msg  [MsgLen];
char msg1 [MsgLen] = "";

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

void loop() {
    if (Serial.available() > 0) {
        int n = Serial.readBytesUntil ('\n', msg, MsgLen);
        msg [n] = 0;        // terminate with null

        if (strcmp (msg1, msg)) {
            Serial.println (msg);
            strcpy (msg1, msg);
        }
    }
}