/*
 * File:   Main.c
 * Author:
 *
 * Created on June 13, 2019, 2:22 PM
 */

#define _XTAL_FREQ 32000000

// PIC16F18875 Configuration Bit Settings

// 'C' source line config statements

// CONFIG1
#pragma config FEXTOSC = OFF      // External Oscillator mode selection bits (EC above 8MHz; PFM set to high power)
#pragma config RSTOSC = HFINT32  // Power-up default value for COSC bits (EXTOSC operating per FEXTOSC bits)
#pragma config CLKOUTEN = OFF    // Clock Out Enable bit (CLKOUT function is disabled; i/o or oscillator function on OSC2)
#pragma config CSWEN = ON        // Clock Switch Enable bit (Writing to NOSC and NDIV is allowed)
#pragma config FCMEN = ON        // Fail-Safe Clock Monitor Enable bit (FSCM timer enabled)

// CONFIG2
#pragma config MCLRE = ON        // Master Clear Enable bit (MCLR pin is Master Clear function)
#pragma config PWRTE = OFF       // Power-up Timer Enable bit (PWRT disabled)
#pragma config LPBOREN = OFF     // Low-Power BOR enable bit (ULPBOR disabled)
#pragma config BOREN = OFF       // Brown-out reset enable bits (Brown-out Reset Enabled, SBOREN bit is ignored)
#pragma config BORV = LO         // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (VBOR) set to 1.9V on LF, and 2.45V on F Devices)
#pragma config ZCD = OFF         // Zero-cross detect disable (Zero-cross detect circuit is disabled at POR.)
#pragma config PPS1WAY = ON      // Peripheral Pin Select one-way control (The PPSLOCK bit can be cleared and set only once in software)
#pragma config STVREN = ON       // Stack Overflow/Underflow Reset Enable bit (Stack Overflow or Underflow will cause a reset)

// CONFIG3
#pragma config WDTCPS = WDTCPS_31// WDT Period Select bits (Divider ratio 1:65536; software control of WDTPS)
#pragma config WDTE = OFF        // WDT operating mode (WDT enabled regardless of sleep; SWDTEN ignored)
#pragma config WDTCWS = WDTCWS_7 // WDT Window Select bits (window always open (100%); software control; keyed access not required)
#pragma config WDTCCS = SC       // WDT input clock selector (Software Control)

// CONFIG4
#pragma config WRT = OFF         // UserNVM self-write protection bits (Write protection off)
#pragma config SCANE = available // Scanner Enable bit (Scanner module is available for use)
#pragma config LVP = OFF          // Low Voltage Programming Enable bit (Low Voltage programming enabled. MCLR/Vpp pin function is MCLR.)

// CONFIG5
#pragma config CP = OFF          // UserNVM Program memory code protection bit (Program Memory code protection disabled)
#pragma config CPD = OFF         // DataNVM code protection bit (Data EEPROM code protection disabled)

#include <xc.h>

unsigned getSPBRG(unsigned baudrate, char brg16, char brgh) {
    unsigned mult;
    if (brg16 == 0 && brgh == 0) mult = 64;
    else if (brg16 == 1 && brgh == 1) mult = 4;
    else mult = 16;

    // baudrate = fOsc / (mult*(spbrg + 1))
    // baudrate * (spbrg + 1) = fOsc / mult
    // spbrg + 1 = (fOsc / mult) / baudrate
    // spbrg = (fOsc / mult) / baudrate - 1
    return (_XTAL_FREQ / mult) / baudrate - 1;
}

void main(void)
{
    TRISA = 0b00000000;
    TRISB = 0b00000000;

    // LATA = 1; __delay_ms(1000);

    PORTC = 0;
    TRISC = 0b10000000; // all outputs, except RX on RC7
    ANSELC = 0b00000000; // disable analog
    //init USART
    // SPEN  RX9   SREN  CREN  ADDEN FERR OERR   RX9D
    RCSTA = 0b10100000;        //    TX9D=0 -->8-bit; SPEN=1, CREN=1, addr-det disabled.
    // CSRC  TX9   TXEN  SYNC  SENDB BRGH  TRMT  TX9D
    TXSTA = 0b00100100;        //    TX9D=0 -->8-bit; BRGH=1; TXEN=1 --> enable, SYNC=0 --> async
    //ABDOVF RCIDL NOP   SCKP  BRG16 NOP   WUE   ABDEN
    BAUDCON = 0b00001000;    //    SCKP=0 -> not inverted, BRG16=1, WUE=0, ABDEN=0

    // LATA = 2; __delay_ms(1000);

    unsigned brg = getSPBRG(4800, 1, 1);
    SPBRGL = brg & 0xFF;
    SPBRGH = brg >> 8;


    // LATA = 3; __delay_ms(1000);

    while(1){
        TXREG = 'X';
        while (!TRMT);
        TXREG = '\n';
        while (!TRMT);
        __delay_ms(500);
        LATA = 4; __delay_ms(1000);
    }

    LATA = 7;
    return;
}