+ Reply to Thread
Results 1 to 2 of 2
  1. #1
    gwntd541's Avatar
    gwntd541 Guest

    Default pic18f27j13 Serial Communitcation Help

    Hi, I'm new to programming with the pic, so I've been having some trouble setting up a serial communication, EUSART1, from my pic to my computer. I am using the pic18f27j13 with a max232 to try and send signals at a baudrate of 115200 to the computer. I'm using realterm to read the signals. But, non-correct Hex values are being read. My attempt is to set the Fosc to be 48Mhz from the internal clock and a baudrate of 115200. Can anyone kindly help me by looking at my code and pointing out any mistakes that I may have made. Thank you.

    Some funky things that I have noticed with realterm. Is that if I send 0x88 it comes out as 0xFA // 1000 1000 -> and get 1111 1010.
    0x00 -> gets 0xF0
    0xFF -> gets 0xFF
    0x1F -> gets 0xF3

    I really don't see any pattern.

    #include <p18f27j13.h>
    #include <stdio.h>
    #pragma config WDTEN = OFF   // Sets watchdog OFF
    #pragma config PLLDIV = 2      // Sets divider to 2. Provides output 4Mhz for 96Mhz PLL
    #pragma config OSC = INTOSCPLL // Sets OSC as INTOSC(8Mhz) Postscalled with a PLL
    #pragma config CFGPLLEN = ON //enables PLL on startup
    #pragma config PLLSEL = PLL96 // selects 96Mhz
    #pragma config XINST = OFF
    // setup functions
    void delay();
    void Wait_Buffer1();
    void setupUSART();
    void delay ()
        unsigned long int count = 0;
        for (count = 0; count < 0x0003FFFF; count ++)
    void Wait_Buffer1(void) 
        while (!TXSTA1bits.TRMT) 
    void setupUSART()
        OSCCONbits.SCS = 0x00; // Selects Primary clock(FOSC) as the clock source
        stdout = _H_USART;
        TXSTA =   0b00100000; //Enable transmit and low baud rate
        RCSTA =   0b10010000; //Enable serial port
        BAUDCON = 0b00001000; //Enable 16 bit baud generator
        SPBRGH = 0;
        SPBRG = 25;
        //target baudrate 115200, 
    void main ()
        unsigned int loop_count = 0;
        TRISCbits.TRISC7 = 1;
        TRISCbits.TRISC6 = 0;
        while (1)
        TXREG1 = 0x1F;

  2. #2
    Join Date
    Nov 2003
    Wellton, U.S.A.

    Default Re: pic18f27j13 Serial Communitcation Help

    Not many of us here do "C" as this is a Pic Basic forum.
    You will do better on a "C" forum.

    Hi, we are pleased to see that you are using our forum.

    We'd like you to become a member of our community. Membership is FREE, please REGISTER and view our forums without these annoying reminders!

    Once registered you may post on the forums, download from the file areas and use the WIKI without interruption.

    Always wear safety glasses while programming.

Members who have read this thread : 1

You do not have permission to view the list of names.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts