/*
 * si5351a RF twotone generator 
 * File:   rf_twotone_generator.c
 * Author: www.henteko.org
 *
 * Created on 2022/03/05, 18:33
 */

#include <xc.h>
#include <stdio.h>
#include "pic16f_i2c.h"
#include "i2c_lcd.h"
#include "si5351a.h"

#pragma config FEXTOSC  = OFF		// external clock off
#pragma config RSTOSC   = HFINT32	// internal clock 16mhz X 2 (pll)
#pragma config MCLRE    = ON		// RA3 disable     
#pragma config FCMEN    = OFF		
#pragma config PWRTE    = OFF		
#pragma config WDTE     = OFF		//
#pragma config BOREN    = ON		//
#pragma config LVP		= OFF		// LVP=off MCLRE=off RA3 input enable

#define _XTAL_FREQ   32000000

#define MAX_FREQ	149999000	// max frequency
#define MIN_FREQ	1000000		// min frequency
#define DEF_FREQ	7000000		// default frequency
#define DIF_FREQ	-10000		// diff frequency
#define EEPROM		0x0000		// EEPROM address
#define MAX_DIFF	1000000		// max difference frequency
#define MIN_DIFF	-1000000	// min difference frequency

long freq;				// frequency
long step;				// frequency up down step
long dfreq;				// difference frequency
unsigned char renc_now, renc_old;	// value of rotary encoder
unsigned char cflag;				// frequency change flag
unsigned char diff;					// frequency up down flag
unsigned char buf[19];				// oled output buffer
unsigned char mode;					// mode flag
unsigned int pos;					// cursor position
	
// millisecond delay
void delay_ms(unsigned int t)
{
	for(; t > 0; t--)
		__delay_ms(1);
}

// eeprom write routine
void eeprom_write_long(unsigned int adr, long data)
{
	unsigned char i;

	for(i = 0; i < 4; i++) {
		eeprom_write(EEPROM + adr * 4 + i, (unsigned char)((data >> (i * 8)) & 0x000000ff));
	}
}

// eeprom read routine
long eeprom_read_long(unsigned int adr)
{
	long d;

	d = (long)eeprom_read(EEPROM + adr * 4);
	d |= (long)eeprom_read(EEPROM + adr * 4 + 1) << 8;
	d |= (long)eeprom_read(EEPROM + adr * 4 + 2) << 16;
	d |= (long)eeprom_read(EEPROM + adr * 4 + 3) << 24;

	return d;
}

// pin change interrupt for rortary encoder 
void interrupt isr(void)
{
	if(IOCIF) {
		if(RC1) {
			if(RC2 == 0) {
				renc_now = 1;
			} else {
				renc_now = 0;
			}
		} else {
			if(RC2) {
				renc_now = 2;
			} else {
				renc_now = 3;
			}
		}
		if((renc_now + 3 + 1) % 3 == renc_old)
			diff = 0;
		if((renc_now + 3 - 1) % 3 == renc_old)
			diff = 1;

		IOCCFbits.IOCCF1 = 0;
		IOCCFbits.IOCCF2 = 0;
		renc_old = renc_now;
		cflag = 1;
	}
}

// write value to eeprom
void setvalue_write(void)
{
	eeprom_write_long(0, dfreq);
	delay_ms(100);
	eeprom_write_long(1, freq);
	delay_ms(100);
}

// read value from eeprom
void setvalue_read(void)
{
	dfreq = eeprom_read_long(0);
	if(dfreq >= MAX_DIFF || dfreq < MIN_DIFF)
		dfreq = DIF_FREQ;
	freq = eeprom_read_long(1);
	if((freq + dfreq)> MAX_FREQ || (freq + dfreq) < MIN_FREQ)
		freq = DEF_FREQ;
}

// lcd output routine
void lcd_output(long f)
{
	unsigned char buf[16];
	unsigned int i; 
	
	if(mode == 0) {
		sprintf(buf, "Fr %9ldHz", f);
		i2c_lcd_goto(0, 0);
	} else {
		sprintf(buf, "Df %9ldHz", f);
		i2c_lcd_goto(1, 0);
	}
	
	for(i = 0; i < 16; i++) {
		i2c_lcd_putch(buf[i]);
		if(i == 5) {
			if(f >= 1000000 || f <= -1000000)
				i2c_lcd_putch('.');
			else
				i2c_lcd_putch(' ');
		}
		if(i == 8) {
			if(f >= 1000 || f <= -1000)
				i2c_lcd_putch('.');
			else
				i2c_lcd_putch(' ');
		}
	}
	if(mode == 0)
		i2c_lcd_goto(0, pos);
	else
		i2c_lcd_goto(1, pos);
}

// change lpf routine
void setFilter(void)
{
	LATCbits.LATC3 = 0;
	LATCbits.LATC4 = 0;
	LATCbits.LATC5 = 0;
	LATCbits.LATC6 = 0;
	LATCbits.LATC7 = 0;
	LATBbits.LATB7 = 0;
	if(freq < 4000000) {
		LATCbits.LATC5 = 1;
	} else if(freq < 8000000) {
		LATCbits.LATC4 = 1;
	} else if(freq < 15000000) {
		LATCbits.LATC3 = 1;
	} else if(freq < 30000000) {
		LATCbits.LATC6 = 1;
	} else if(freq < 55000000) {
		LATCbits.LATC7 = 1;
	} else {
		LATBbits.LATB7 = 1;
	}
}

void main(void)
{
	unsigned char sw0_state;
	unsigned int tim0;

	ANSELB = 0x00;			// Port B all digital
	TRISBbits.TRISB4 = 1;	// RB4 i2c sda
	TRISBbits.TRISB6 = 1;	// RB6 i2c scl
	ODCONBbits.ODCB4 = 1;	// RB4 Open-Drain set
	ODCONBbits.ODCB6 = 1;	// RB6 Open-Drain set
	TRISBbits.TRISB7 = 0;	// RB7 filter control

	SSP1DATPPS = 0x0C;		// RB4 i2c sda
	RB4PPS     = 25;		// RB4 i2c sda
	SSP1CLKPPS = 0x0E;		// RB6 i2c scl
	RB6PPS     = 24;		// RB6 i2c scl

    ANSELC = 0x00;			// Port C all digital
	TRISCbits.TRISC3 = 0;	// PC3 - PC7 filter control
	TRISCbits.TRISC4 = 0;
	TRISCbits.TRISC5 = 0;
	TRISCbits.TRISC6 = 0;
	TRISCbits.TRISC7 = 0;
	
	
	TRISCbits.TRISC0 = 1;	// RC0 sw input for step and memory
	TRISCbits.TRISC1 = 1;	// RC1 rotaly encoder
	TRISCbits.TRISC2 = 1;	// RC2 rotaly encoder
	WPUCbits.WPUC0 = 1;		// RC0 weak pull-up enable
	WPUCbits.WPUC1 = 1;		// RC1 weak pull-up enable
	WPUCbits.WPUC2 = 1;		// RC2 weak pull-up enable
	IOCCNbits.IOCCN1 = 1;	// RC1 interrupt-on-change negative edge
	IOCCNbits.IOCCN2 = 1;	// RC2 interrupt-on-change negative edge
	
	InitI2C();
	delay_ms(10);
	i2c_lcd_init(26);
	si5351_init();

	setvalue_read();
	
	step = 1000000;
	pos = 5;
	diff = 0;
	cflag = 0;
	sw0_state = 0;
	tim0 = 0;

	mode = 0;
	lcd_output(freq);
	mode = 1;
	lcd_output(dfreq);
	mode = 0;

	i2c_lcd_goto(0, pos);
	i2c_lcd_cursor(2);
	
	si5351_setfreq(0, freq);
	si5351_setfreq(1, freq + dfreq);
	setFilter();

	IOCIE = 1;				// intertupt-on-change interrupt enable
	GIE = 1;				// general interrupt enable

	while(1) {
	
		if(cflag) {
			if(mode == 0) {
				if(diff) {
					if((freq + step ) <= MAX_FREQ)
						freq += step;
				} else {
					if((freq - step) >= MIN_FREQ)
						freq -= step;
				}
				si5351_setfreq(0, freq);
				si5351_setfreq(1, freq + dfreq);
				setFilter();
				lcd_output(freq);
			} else {
				if(diff) {
					if((dfreq + step ) <= MAX_DIFF)
						dfreq += step;
				} else {
					if((dfreq - step) >= MIN_DIFF)
						dfreq -= step;
				}
				lcd_output(dfreq);
			}
			cflag = 0;
		}
		
		if(PORTCbits.RC0 == 0) {
			sw0_state = 1;
			delay_ms(20);
			tim0++;
		}
		if(sw0_state && PORTCbits.RC0 == 1) {
			sw0_state = 0;
			tim0 = 0;
			if(step == 1) {
				step = 10;
				pos = 12;
			} else if(step == 10) {
				step = 100;
				pos = 11;
			} else if(step == 100) {
				step = 1000;
				pos = 9;
			} else if(step == 1000) {
				step = 10000;
				pos = 8;
			} else if(step == 10000) {
				step = 100000;
				pos = 7;
			} else if (step == 100000) {
				step = 1000000;
				pos = 5;
			} else if(step == 1000000) {
				step = 1;
				pos = 13;
			}
			if(mode == 0)
				i2c_lcd_goto(0, pos);
			else
				i2c_lcd_goto(1, pos);
		}

		// difference frequency setup routine and write memory
		if(tim0 > 60) {
			sw0_state = 0;
			tim0 = 0;
			if(mode == 0) {
				i2c_lcd_goto(0, 0);
				i2c_lcd_puts("Difference Setup");
				delay_ms(2000);
				mode = 1;
				step = 1000;
				pos = 9;
				lcd_output(dfreq);
			} else {
				mode = 0;
				GIE = 0;
				i2c_lcd_goto(0, 0);
				i2c_lcd_puts("==Write Memory==");
				delay_ms(2000);
				setvalue_write();
				si5351_setfreq(1, freq + dfreq);
				lcd_output(freq);
				GIE = 1;
			}
		}
	}
}