Searching and parsing data from serial.read

Projects Programming
5

Here's another way without using strtok():

char oneReading[25];
char *ptr;
char temp[8];

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

void loop() {
  int charsRead;
  
  while (Serial.available() > 0)    // Using test input data: 80 5C 66 BE E0 2E
  {
    charsRead = Serial.readBytesUntil('\n', oneReading, sizeof(oneReading) - 1); // Read until '\n' or 24 chars
    oneReading[charsRead] = '\0';
    ptr = strstr(oneReading, "BE ");        // Look for sentinel
   
    if (ptr != NULL) {
      strncpy(temp, ptr + 6, 2);            // Flip the digits; take last 2 chars first...
      strncpy(&temp[2], ptr + 3, 2);        // ...now the first two past the "BE "
      temp[4] = '\0';                       // Make it a string
      rpm = (int) strtol(temp, &ptr, 16);;
      Serial.println(rpm);
    }
  }
}

This assumes that "BE " always preceeds the rpm data and that string is not an earlier hex number.