[SOLVED] Interfacing HC-06 with PIC

[bmuigai]

Hi everyone,
I am trying to make an interface between an android phone and microcontroller using the HC-06 Bluetooth module. I started this morning by trying it out on arduino uno and as there are many tutorials on the internet about the same, I managed in perhaps the first hour to send characters from my phone.

But am a fan of PIC microcontrollers and so I decided to go for the major adventure of the day. As it however turns out about 12 hours later, its turning into a nightmare. I can pair with my phone and initialize the UART communication without problems. when I start typing, I can also tell that there is signal being detected by my PIC. But there seems to be no data transfer except for an error. What could be wrong with my code.

I'm using MikroC and Mplab with PICKIT3 and Blueterm2 in android phone

 unsigned short counter=0;

void interrupt() {
  if (INTCON.TMR0IF) {
    if (counter >= 20) {
      Soft_UART_Break();
      counter = 0;              // reset counter
    }
    else
      counter++;                // increment counter
    INTCON.TMR0IF = 0;            // Clear Timer0 overflow interrupt flag
    }
}

void main(){
unsigned char error, datain, byte_read=0, i, k=100, j=9, l=200;
    TRISB.F3=0;
    TRISA=0;
    PORTB=0;
    PORTA=0;
    ANSEL=0;
    CMCON=7;
    OSCCON=0B01001100;
     OPTION_REG = 0x04;            // TMR0 prescaler set to 1:32
      TMR0=0;
      INTCON.TMR0IE = 0;              // Enable Timer0 overflow interrupt
      
    for(i=0; i<3; i++){
        PORTA=255;
        Delay_ms(100);
        PORTA=0;
        Delay_ms(100);
        }
    
    error = Soft_UART_Init(&PORTB, 4, 5, 9600, 0);
    Eeprom_Write(0x00, error);
  if (error > 0) {
         Eeprom_Write(0x01, error);
         delay_ms(10);
         /*PORTA=error;  Delay_ms(30);
         PORTA=0;  Delay_ms(30);*/
    while(1);                            // Stop program
  }
  Delay_ms(100);

  while(1) {                              // Endless loop
      INTCON.GIE = 1;               // Global interrupt enable
      INTCON.TMR0IE = 1;              // Enable Timer0 overflow interrupt
    byte_read = Soft_UART_Read(&error);   // Read byte, then test error flag
        INTCON.GIE = 0;                                         // Global interrupt disable
      INTCON.TMR0IE = 0;              // Disable Timer0 overflow interrupt
    if(error==0){     
          Eeprom_Write(j, byte_read);	//save data in Eeprom
          j+=1;  if(j>200) j=9;
          PORTA=3;  Delay_ms(30);		
          Eeprom_Write(0x04, j);		////save number of characters in Eeprom
          PORTA=0;  Delay_ms(30);
          PORTA = byte_read;
          //Eeprom_Write(j, byte_read);
      }
      else Eeprom_Write(0x05, error);	//save error message in Eeprom

  }
}

 

[milan.rajik]

TRISB settings ? Set UART Rx pin as input pin.

 

[bmuigai]

I thought

Soft_UART_Init(&PORTB, 4, 5, 9600, 0);

does that internally. Anyway, I did as you stated but I still get no data. I get the error 255 which is related to

Soft_UART_Break();

in the timer0 interrupt. MikroC document suggested it as

Soft_UART_Read(&error);

is a blocking function call. Previously code seemed to hang in the read operation until I added the interrupt.

 

[bmuigai]

I have decided to use the hardware UART and I now seem to be getting data sent from Blueterm. However, all the data received is 0xFF no matter what character I transmit. If anyone could point out why this is the case I would really much appreciate..