bluetooth transmission failure (Esplora to Mega)

Using Arduino Networking, Protocols, and Devices
1

Hey,

I´m trying to control a robotic arm, mounted on a track vehicle with an Arduino Esplora.
The servo-arm and the vehicle are connected with an Arduino Mega wich recieves its data from the Esplora via bluetooth (using the HC05 bluetooth shield). For that I need to transmit 8 different variables.

Most of the time that works perfectly well, however when I'm trying to parse the data I will sometimes recieve wrong values (like every 5th or 6th time).

I'm pretty sure that the wiring is correct, so I think my code is wrong. It would be great if you guys could check it for mistakes :slight_smile:

Here is the code (shortened) of the Master (Esplora):

#include <SoftwareSerial.h>

SoftwareSerial mySerial (11, 3); //RX, TX

int Xpos1 = 90; //Servo Starting position (90° at the beginning)
int Ypos2 = 90;
int Ypos3 = 90;
int Ypos4 = 90;
int Xpos5 = 90;
int Ypos6 = 90;

int X=0;           // Variables for the vehicle
int Y=0;

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

void loop() {
  mySerial.print("<");
  mySerial.print(Xpos1);
  mySerial.print(",");
  mySerial.print(Ypos2);
  mySerial.print(",");
  mySerial.print(Ypos3);
  mySerial.print(",");
  mySerial.print(Ypos4);
  mySerial.print(",");
  mySerial.print(Xpos5);
  mySerial.print(",");
  mySerial.print(Ypos6);
  mySerial.print(",");
  mySerial.print(X);
  mySerial.print(",");
  mySerial.print(Y);
  mySerial.print(">");
}

and this is the code of the Slave (Mega):

int Xpos1 = 90;
int Ypos2 = 90;
int Ypos3 = 90;
int Ypos4 = 90;
int Xpos5 = 90;
int Ypos6 = 90;

int X=0
int Y=0

const byte numChars = 32;
char receivedChars[numChars];
char tempChars[numChars];        // temporary array for use when parsing

// variables to hold the parsed data


boolean newData = false;

//============

void setup() {
  Serial.begin(9600);
  Serial1.begin(9600);
}

void loop() {
 recvWithStartEndMarkers();
  if (newData == true) {
    strcpy(tempChars, receivedChars);
    // this temporary copy is necessary to protect the original data
    parseData();
    showParsedData();
    newData = false;
  }
}

void recvWithStartEndMarkers() {
  static boolean recvInProgress = false;
  static byte ndx = 0;
  char startMarker = '<';
  char endMarker = '>';
  char rc;

  while (Serial1.available() > 0 && newData == false) {
    rc = Serial1.read();

    if (recvInProgress == true) {
      if (rc != endMarker) {
        receivedChars[ndx] = rc;
        ndx++;
        if (ndx >= numChars) {
          ndx = numChars - 1;
        }
      }
      else {
        receivedChars[ndx] = '\0'; // terminate the string
        recvInProgress = false;
        ndx = 0;
        newData = true;
      }
    }

    else if (rc == startMarker) {
      recvInProgress = true;
    }
  }
}

//============

void parseData() {      // split the data into its parts

  char * strtokIndx; // this is used by strtok() as an index

  strtokIndx = strtok(tempChars, ",");     // get the first part - the string
  Xpos1 = atoi(strtokIndx);     // convert this part to an integer

  strtokIndx = strtok(NULL, ","); // this continues where the previous call left off
  Ypos2 = atoi(strtokIndx); 

  strtokIndx = strtok(NULL, ","); 
  Ypos3 = atoi(strtokIndx);

  strtokIndx = strtok(NULL, ",");
  Ypos4 = atoi(strtokIndx);

  strtokIndx = strtok(NULL, ",");
  Xpos5 = atoi(strtokIndx);

  strtokIndx = strtok(NULL, ",");
  Ypos6 = atoi(strtokIndx);

  strtokIndx = strtok(NULL, ",");
  X = atoi(strtokIndx);

  strtokIndx = strtok(NULL, ",");
  Y = atoi(strtokIndx);
}

If you can spot any mistake it would be great if you could help me erasing it.
As you may notice I used Example 5 of the Arduino Serial "Tutorial" here in this forum, so I don't 100% know what I'm doing actually, sorry for that.

Thanks in advance for your efforts!