Reading data from joystick through bluetooth HC-05 module

Other Hardware Sensors
7

Here is how I do that using 2 Unos each with a HC05 Bluetooth module. The sender gets the joystick values and makes a packet to send. The receiver uses methods from the serial input basics tutorial to receive and parse the packet. You may need to change some pin numbers and baud rate to suit your setup. Note that SoftwareSerial will very likely not work above 38400 baud.

Sender

#include <SoftwareSerial.h>

const byte xPin = A0;
const byte yPin = A1;

SoftwareSerial ss(4, 7);

void setup()
{
   Serial.begin(115200);
   ss.begin(9600);
}

void loop()
{
   static unsigned long timer = 0;
   unsigned long interval = 1000;
   if (millis() - timer >= interval)
   {
      timer = millis();
      int xValue = analogRead(xPin);
      int yValue = analogRead(yPin);
      Serial.print("x value = ");
      Serial.print(xValue);
      Serial.print("   y value = ");
      Serial.println(yValue);
      char buffer[15];
      snprintf(buffer, 14, "%d,%d", xValue, yValue);
      //Serial.println(buffer);
      ss.println(buffer);  // must have a line feed (\n) to terminate the packet
   }
}

Receiver

#include <SoftwareSerial.h>

int xValue = 0;
int yValue = 0;

const byte numChars = 32;
char receivedChars[numChars];   // an array to store the received data

boolean newData = false;

SoftwareSerial ss(4, 7);

void setup()
{
   Serial.begin(115200);
   ss.begin(9600);
}

void loop()
{
 recvWithEndMarker();
   //showNewData();
   if (newData)
   {
      parseData();
   }
}

void recvWithEndMarker()
{
   static byte ndx = 0;
   char endMarker = '\n';
   char rc;

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

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

void showNewData()
{
   if (newData == true)
   {
      Serial.print("This just in ... ");
      Serial.println(receivedChars);
      //newData = false;
   }
}

void parseData()
{
   char *strings[2]; // an array of pointers to the pieces of the above array after strtok()
   char *ptr = NULL; byte index = 0;
   ptr = strtok(receivedChars, ",");  // delimiter comma
   while (ptr != NULL)
   {
      strings[index] = ptr;
      index++;
      ptr = strtok(NULL, ",");
   }
   //Serial.println(index);
   /*
   // print all the parts
   Serial.println("The Pieces separated by strtok()");  
   for (int n = 0; n < index; n++)
   {
      Serial.print("piece ");
      Serial.print(n);
      Serial.print(" = ");
      Serial.println(strings[n]);
   }
   */
   // convert string data to numbers
   xValue = atoi(strings[0]);
   yValue = atoi(strings[1]);
      
   Serial.print("x value = ");
   Serial.print(xValue);
   Serial.print("   y value = ");
   Serial.print(yValue);
   
   Serial.println(); // blank line
   newData = false;
}

Reciever output

> x value = 111   y value = 1022
x value = 259   y value = 0
x value = 974   y value = 549
x value = 914   y value = 651
x value = 377   y value = 360
x value = 385   y value = 347
x value = 383   y value = 349
x value = 382   y value = 341
x value = 385   y value = 355