/*
 * File:   TX_RF.c
 * Author: George Panagopoulos
 * Processor: PIC12F1822
 *
 * Created on 25 May 2014, 11:15
 *
 *          
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <xc.h>


// #pragma config statements should precede project file includes.
// Use project enums instead of #define for ON and OFF.



// CONFIG1
#pragma config FOSC = XT        // Oscillator Selection (XT Oscillator, Crystal/resonator connected between OSC1 and OSC2 pins)
#pragma config WDTE = OFF       // Watchdog Timer Enable (WDT disabled)
#pragma config PWRTE = ON       // Power-up Timer Enable (PWRT enabled)
#pragma config MCLRE = OFF      // MCLR Pin Function Select (MCLR/VPP pin function is digital input)
#pragma config CP = OFF         // Flash Program Memory Code Protection (Program memory code protection is disabled)
#pragma config CPD = OFF        // Data Memory Code Protection (Data memory code protection is disabled)
#pragma config BOREN = OFF       // Brown-out Reset Enable (Brown-out Reset enabled)
#pragma config CLKOUTEN = OFF   // Clock Out Enable (CLKOUT function is disabled. I/O or oscillator function on the CLKOUT pin)
//#pragma config IESO = ON        // Internal/External Switchover (Internal/External Switchover mode is enabled)
//#pragma config FCMEN = ON       // Fail-Safe Clock Monitor Enable (Fail-Safe Clock Monitor is enabled)

// CONFIG2
#pragma config WRT = OFF        // Flash Memory Self-Write Protection (Write protection off)
#pragma config PLLEN = OFF      // PLL Enable (4x PLL disabled)
#pragma config STVREN = OFF     // Stack Overflow/Underflow Reset Enable (Stack Overflow or Underflow will not cause a Reset)
#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (Vbor), low trip point selected.)
#pragma config LVP = OFF        // Low-Voltage Programming Enable (High-voltage on MCLR/VPP must be used for programming)

#define _XTAL_FREQ          4000000      //4MHZ external oscillator used in _delay()

void USARTWriteString(const char *,int);
void USARTWriteChar(char);
void USART_Init(uint16_t baud_rate);


void USART_Init(uint16_t baud_rate)
{
    //SPBRG
    switch(baud_rate)
    {
     case 1200:
        SPBRG=207;
        break;
     case 2400:
        SPBRG=103;
        break;
     case 9600:
        SPBRG=25;
        break;
    }
    //TXSTA
    TXSTAbits.TX9=0;  //8 bit transmission
    TXSTAbits.TXEN=1; //Transmit enable
    TXSTAbits.SYNC=0; //Async mode
    TXSTAbits.BRGH=1; //High speed baud rate

    //RCSTA
    RCSTAbits.SPEN=1;   //Serial port enabled
    RCSTAbits.RX9=0;    //8 bit mode
}


void USARTWriteChar(char ch)
{
  while(!PIR1bits.TXIF);
  TXREG=ch;
}

void USARTWriteString(const char *str,int length)
{
    int cnt=0;
    for(cnt=0;cnt<length;cnt++)
    {
      USARTWriteChar(str[cnt]);
    }
    USARTWriteChar(13);    
    USARTWriteChar(10);
}

int main(int argc, char** argv)
{
    char* tx_message = "We love instructables!";
    
    //configure PORT
    CPSCON0bits.CPSON=0;    //disable capacitive sensing!
    ANSELA=0;               //set all analog pins to digital I/O
    LATA=0;                 //all output pins low.
    TRISA=0b000000;         //

    USART_Init(1200);

    while(1)
    {        
        USARTWriteString(tx_message,22);
                      
        __delay_ms(50);             //give it some time before the next transmission
                                    //as the delay becomes bigger the receiver struggles 
                                    //to adjust its gain on the transmitted signal
    }
    return (EXIT_SUCCESS);
}