[Moved]: can any one help me out for software uart for pic18f452 .

[karthims]

Actually i am using pic18f452 as well as Hitech C18 compiler IDE MPLABX.I tried many times for Software uart myself but cant able to achieve that.So i am asking your help please be need full friends.
Thanks in advance for your help.

Ic-pic18f452
Crystal -10mhz
Compiler-Hitech C18
IDE-MPLABX

 

[paulfjujo]

hello,

Show us what you allready did ...

This piece of code just to put you on the rails.. (done for a 18F252 but must be compliant..)

//gestionnaire d'interruption
//------------------------------
// High priority interrupt vector
#pragma code InterruptVectorHigh = 0x08
void InterruptVectorHigh (void)
{
  _asm
    goto InterruptHandlerHigh //jump to interrupt routine
  _endasm
}


// High priority interrupt routine
#pragma code
#pragma interrupt InterruptHandlerHigh
void InterruptHandlerHigh ()
{
  static char i ; // doit etre statique pour conserver sa valeur entre les IT
  static char C ;
  static int T;
//======== SERIAL======================
if(PIR1bits.RCIF) // si un car arrive
   {
   C =ReadUSART(); // le lire => RAZ  RCIF
   if(RCSTAbits.FERR || RCSTAbits.OERR)
     {
      RCSTAbits.CREN = 0 ;
      RCSTAbits.CREN= 1 ;
     }
    // if you want an Echo 
     while(BusyUSART()); // par sécurité
     WriteUSART(C); 

     if( C == BS)  // correct the buffer (Back Shift)
        {
         if(i>0){
             i--;  }
        }
      else {
      if(C != CR && i<MAX_LEN)   // if not <CR> touch or size less than maximum of buffer 
      {
        buffer[i++]=C ; // store it into the buffer
        }else
        {
         buffer[i]='\0'; // fin de chaîne si CR
         i=0;
         received =1;  // flag to test inside the main .. for displaying the result on LCD or Terminal
       }
      }
    }
}

use UART library..
read explanations ...on MPLAB_C18_Libraries_51297f.pdf

not usable like this
need init of many parameter
buffer size..etc ..
lets'go.

 

[milan.rajik]

There is no Hi-Tech C18 Compiler. Hi-Tech made PICC and PICC-18 Compilers. Microchip made C18 Compiler.

So, are you using C18 Compiler ? with MPLAB X ?

Have you seen software UART example codes at saeedsolutions.blogspot.com ?

https://saeedsolutions.blogspot.in/2012/07/pic12f675-software-uart-bit-banging.html

 

[Vbase]

There is no Hi-Tech C18 Compiler. Hi-Tech made PICC and PICC-18 Compilers. Microchip made C18 Compiler.

So, are you using C18 Compiler ? with MPLAB X ?

You can download for free and use XC8 with MPLAB X, it is a C compiler for 8 bits PICs, it is a new version of HI-TECH PICC and PICC-18 Compilers together.

 

[karthims]

First of all Thanks to all for your quick reply...

Actually i am the new one to micro controllers.I just tried by the UART protocol logic like start bit=high,stop bit=low . I cant able to develop that, so i have no snippet for my code.

I tried like as saeedsolutions.blogspot.com but it is not working for me.


My compiler -HI-TECH PICC18-PRO.

Is there any possibilities to do software uart using XC8..? if so just let me know any material or pages to support

 

[milan.rajik]

The Software UART code at saeedsolutions.blogspot.com work fine. I have tested it myself. I have also ported it to PIC18F and it works fine. I have not tested with PIC16F. Please zip and post your complete MPLAB X Hi-Tech PICC-18 project files. I will test it.

 

[karthims]

This is my code...I referred https://saeedsolutions.blogspot.in/

---

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//***It is for reception ***//
 
#include <htc.h>
 
//#pragma config CONFIG1H = 0x22
__CONFIG(1, OSC_HS & OSCS_OFF);
//#pragma config CONFIG2L = 0xF
__CONFIG(2, PWRT_OFF & BOR_ON & BORV_20);
//#pragma config CONFIG2H = 0xE
__CONFIG(3, WDT_OFF & WDTPS_128);
//#pragma config CONFIG3H = 0x0
__CONFIG(4, CCP2MUX_OFF);
//#pragma config CONFIG4L = 0x80
__CONFIG(5, STVR_OFF & LVP_OFF);
//#pragma config CONFIG5L = 0xF
__CONFIG(6, CP0_OFF & CP1_OFF & CP2_OFF & CP3_OFF);
//#pragma config CONFIG5H = 0xC0
__CONFIG(7, CPB_OFF & CPD_OFF);
//#pragma config CONFIG6L = 0xF
__CONFIG(8, WRT0_OFF & WRT1_OFF & WRT2_OFF & WRT3_OFF);
//#pragma config CONFIG6H = 0xE0
__CONFIG(9, WRTC_OFF & WRTB_OFF & WRTD_OFF);
//#pragma config CONFIG7L = 0xF
__CONFIG(10, EBTR0_OFF & EBTR1_OFF & EBTR2_OFF & EBTR3_OFF);
//#pragma config CONFIG7H = 0x40
__CONFIG(11, EBTRB_OFF);
 
 
#define Transmitter RC0
#define Receiver RC1
#define Transmitter_dir TRIC0=0
#define Receiver_dir    TRIC1=1
 
#define _XTAL_FREQ 10000000 //10MHz
#define BitCount          8
#define Baudrate              9600    //Baud rate
#define OneBitDelay           (2500000/Baudrate)
 
 
unsigned char UART_Receive(void)
{
    unsigned char DataValue = 0;
    while(Receiver==1);
 
    __delay_us(OneBitDelay);
    __delay_us(OneBitDelay/2); 
 
    for ( unsigned char i = 0; i<BitCount; i++ )
    {
        if ( Receiver == 1 )
        {
            DataValue += (1<<i);
        }
 
        __delay_us(OneBitDelay);
    }
 
    if ( Receiver == 1 )
    {
        __delay_us(OneBitDelay/2);
        return DataValue;
    }
    else                      //some error occurred !
    {
        __delay_us(OneBitDelay/2);
                return 0;
    }
}
 
void PORT_INIT()
 {
   Transmitter;
   Receiver;
   Transmitter_dir;
   Receiver_dir;  
 }

---

 

[karthims]

If you have any snippet or working code that will be more useful for me....
Thank you

 

[paulfjujo]

hello,

C18 code for 18F258 .. can be adapted for 18F452
just select the part of code for UART ...