How to deal with software serial RX buffer overflow [optimisation][alternatives]

Projects Programming
13

My code was also flawed, which I changed to:

(This is the working function I use now)

int flush_buffer_until(const char UNTIL[], const int UNTIL_LEN, bool stop_at_ok = false)
{
  // TODO Add timeout to return -1

  int u = 0;    // Until message incremental counter
  int8_t o = 0; // OK message incremental counter
  char in;      // Incoming byte

  if (UNTIL == OK_TEXT)
  {
    // Override for when you only want to stop on OK
    stop_at_ok = false;
  }

  // If UNTIL_LEN <= 0 we have an issue with passing arguments
  while (UNTIL_LEN > 0)
  {
    while (hat_port.available() > 0)
    {
      in = hat_port.read(); // Incoming byte
      if (in == UNTIL[u])
      {
        u++;   // End of message is approaching
        o = 0; // We can stop looking for OK if we were
      }
      else if ((in == OK_TEXT[o]) && stop_at_ok)
      {
        o++; // We're approaching the OK message
        u = 0; // We can stop looking for UNTIL if we were
      }
      else
      {
        if (in == OK_TEXT[0] && stop_at_ok)
        {
          // We stopped the last sequence of OK, but we may have started a new sequence
          o = 1;
          continue;
        }
        else if (in == UNTIL[0])
        {
          // We stopped the last sequence of UNTIL, but we may have started a new sequence
          // We don't continue here in case UNTIL is of length 1
          u = 1;
        }
        else
        {
          // Neither OK, UNTIL or their starting letters were seen, so reset their counters
          u = 0;
          o = 0;
          continue;
        }
      }
      if (u >= UNTIL_LEN)
      {
        return 1;
      }
      else if (o >= OK_LEN)
      {
        return 2;
      }
    }
  }
  return -1;
}

This was also an issue, but is now fixed.