Bluetooth Module (HC-06) Interfacing with PIC Microcontroller [Step by Step Picture]

Bluetooth device has been becoming very popular for wireless communication . Bluetooth is a device that helps you to communicate with other through wireless connection . I am not going to describe about Bluetooth technology . If you have more interest about it , please follow the link of wikipedia Link.

In this tutorial , i will show you how to interface Bluetooth module with pic microcontroller . I am using HC-06 Bluetooth Module and PIC 18f2550 microcontroller for this purpose .

 

We will use USART to make connection between pic18f2550 and HC-06 . So, here is an important thing Baud Rate . This bluetooth module supports 38400 Baud Rate . Actually i don't have much knowledge about Baud Rate . All i know , it's a Symbol rate and differs from bit rate. Higher baud rate makes higher speed of transmission and connection speed. I had tried to understand it clearly from wikipedia , but i failed to completely understand . If you would like to know about Baud Rate , please try these links.

 Baud Rate [Wikipedia]

Baud Rate[MathWorks]

Baud Rate can be changed using  "AT Command"  like GSM Module. I tried , but i didn't get any impact . I am giving another link if you would like to change it . I think  Baud Rate 38400 is fine , i didn't change it . 

How to Change Baud Rate

I think , it's not very essential and that's my personal opinion . Now lets start and take a look at the picture :

HC-06 Bluetooth Module

HC-06 Bluetooth Module [Details] :

Default password: 1234
Baud rate: 38400
Dimensions: 1.73 in x 0.63 in x 0.28 in (4.4 cm x 1.6 cm x 0.7 cm)
PIN OUT
PIN DESCRIPTION
1 KEY
2 VCC
3 GND
4 TXD
5 RXD

MikroC Project :

Now open MikroC and Create a new Project .If you are an expert you don't have to follow this steps .

Note :

Our microcontroller will only transmits and receives data from HC-06 . For this purpose we will use UART of MikroC . As we did in serial communication. PIC18f2550 transmitted text data and that was taken by our computer and PIC18f2550 also received data text from computer. That was the basic idea. Here we are using HC-06 instead of computer. 

Mikro C Library Funtions :

UARTx_Init:  This function will initialize USART option of  Microcontroller with Baud rate . We will use baud rate 38400 . The code will be look like this :

 UART1_Init(38400);

UARTx_Data_Ready: This will check if it is available to read or transmit data .

UARTx_Read_Text: To read text data .Look at the example .

if (UART1_Data_Ready() == 1) {

UART1_Read_Text(  txt,  ")" , 13); }

This is checking if data is available to read . ")" means , txt car array variable will be being stored until the ")" will found . 13 means to try for 13 times . So , i think our text should not be longer than 11 character .

UARTx_Write_Text: This will send text data . Look at the example :

if (UART1_Tx_Idle() == 1) {// this will check , if the last data transmission is completed

 UART1_Write_Text("button2");
 }

Reducing Noise :

To reduce noise , we will use a trick . Before reading the data text we will keep a function and this will check  first character . If the character is '(' , it will be checked by an if statement. Finally read text function will be performed until the char  ')' will be found. That means microcontroller will show us only the text between '(' and ')' . Please follow the example :

If we send  (Omnia) , Lcd will show "Omnia" . If we send (PinkFloyd) , we will get "PinkFloyd" . Unless we cant get any text output.  If we send "(fee ra huri" , this will show no output .

Source Code :

 // LCD module connections  





 sbit LCD_RS at LATB7_bit;  
 sbit LCD_EN at LATB6_bit;  
 sbit LCD_D4 at LATB5_bit;  
 sbit LCD_D5 at LATB4_bit;  
 sbit LCD_D6 at LATB3_bit;  
 sbit LCD_D7 at LATB2_bit;  
 sbit LCD_RS_Direction at TRISB7_bit;  
 sbit LCD_EN_Direction at TRISB6_bit;  
 sbit LCD_D4_Direction at TRISB5_bit;  
 sbit LCD_D5_Direction at TRISB4_bit;  
 sbit LCD_D6_Direction at TRISB3_bit;  
 sbit LCD_D7_Direction at TRISB2_bit;  
 // End LCD module connections  
 char txt[16];  
 char chk;  
 int i=0,ckop=0;  
 void main() {  
 ADCON1=0x0E;         // Configure RE1 pin as input  
 CMCON=7;  
 for(i=0;i<16;i++){txt[i]=' ';}  
   TRISA.F3=1;  
    TRISA.F4=1;        // Initialize ADC  
      TRISA.F5=1;  
      TRISC.F0=1;  
  Lcd_Init();   
   UART1_Init(38400);  
      delay_ms(200);            // Initialize LCD  
  Lcd_Cmd(_LCD_CLEAR);        // Clear display  
  Lcd_Cmd(_LCD_CURSOR_OFF);     // Cursdhhdor off  
   Lcd_Cmd(_LCD_CLEAR);  
  Lcd_Out(1, 4, "Welcome");  
  Lcd_Out(2, 2, "pictutorial.net");  
  delay_ms(1500);  
   Lcd_Cmd(_LCD_CLEAR);  
   Lcd_Out(1, 2, "Received Data");  
  while(1){  
   ckop=2;  
 if (UART1_Data_Ready() == 1){  
  chk = UART1_Read();  
  for(i=0;i<16;i++){txt[i]=' ';}  
  }  
   if(PORTA.F3==0){  
    delay_ms(1000);  
  if (UART1_Tx_Idle() == 1 && ckop==2) {  
  UART1_Write_Text("button1");  
  }  
  ckop=4;  
  }  
   if(PORTA.F4==0){  
      delay_ms(1000);  
  if (UART1_Tx_Idle() == 1 && ckop==2) {  
  UART1_Write_Text("button2");  
  }  
   ckop=4;  
  }  
  if(PORTA.F5==0){  
  UART1_Write_Text("AT+BAUD4");  
  }  
  if(PORTC.F0==0){  
  UART1_Write_Text("AT+BAUD6");  
  }  
      if(chk=='('){  
  UART1_Read_Text(txt,")",13);  // reads text until 'enter' is found  
  Lcd_Cmd(_LCD_CLEAR);  
  Lcd_Out(1, 2, "Received Data");  
  Lcd_Out(2,1,txt);  
  delay_ms(500);  
   for(i=0;i<16;i++){txt[i]=' ';}  
  }  
 }  
 }  

Now Save The Hex File

Circuit Diagram :

Circuit

Practical

MikroC USART Terminal Set Up :

Result

Download Source Code and Images(google drive)

Thank You!