/**************************************************************
	PIC18F DDS chip control
		DDS: AD9834 (Analog Devices Co.)
		PIC: PIC18F14K50
			 16MHz Internal Clock Oscillator
2013.05.02  origin www.henteko.org
***************************************************************/
#include <p18f14k50.h>
#include <delays.h>
#include <EEP.h>
#include <stdio.h>
#include "lcd.h"

#pragma config FOSC = IRC
#pragma config WDTEN = OFF
#pragma config FCMEN = OFF
#pragma config PWRTEN = ON
#pragma config BOREN = ON
#pragma config BORV = 30
#pragma config LVP = OFF
#pragma config MCLRE = OFF
#pragma config HFOFST = ON
#pragma config PLLEN = OFF
#pragma config CPUDIV = NOCLKDIV

#define DDS_FSYNC	LATCbits.LATC5	// AD9834 sync
#define DDS_SCLK	LATAbits.LATA5	// AD9834 clock
#define DDS_SDATA	LATAbits.LATA4	// AD9834 data
#define MAX_FREQ	33000000	// max frequency
#define MIN_FREQ	-33000000	// min frequency
#define DEF_FREQ	10000000	// default frequency
#define EEPROM		0x0000		// EEPROM address
unsigned char tmp[17];			// lcd output srting
unsigned long freq;			// VFO frequency
long offset;				// IF frequency
unsigned long step;			// frequency up down step
unsigned char diff;			// frequency diff mode
unsigned char renc_now, renc_old;	// value of rotary encoder
unsigned char mode;			// 0:normal 1:IF setup mode
unsigned char cflag;			// frequency change flag

/***************************************************************
	ms step delay 
***************************************************************/
void delay_ms(unsigned int t)
{
	for(; t > 0; t--)		// 16MHz clock
		Delay1KTCYx(4);		// 1ms: 0.001 / ((1 / (16000000 / 4)) * 1000) = 12 
}

/***************************************************************
	us step delay 
***************************************************************/
void delay_us(unsigned int t)
{
	for(; t > 0; t--) {		// 16MHz clock
		Delay1TCY();		// 1 / (16000000 / 4) = 0.25us ...  0.25 * 4 = 1us
		Delay1TCY();		// Delay1TCY() = nop()
		Delay1TCY();
		Delay1TCY();
	}
}

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

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

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

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

	return d;
}

/***************************************************************
	serial data send (MSB first)
***************************************************************/
void dds_dataset(unsigned long data, unsigned int bt)
{
	unsigned int i;

	DDS_FSYNC = 0;

	for(i = bt; i > 0 ; i--) {
		DDS_SDATA = (data >> (i - 1)) & 0x00000001;
		DDS_SCLK = 0;
		DDS_SCLK = 1;	
	}
	DDS_FSYNC = 1;
}

/***************************************************************
	AD9834 DDS control (frequency to serial code)
***************************************************************/
void freq2serial(unsigned long f)
{
	unsigned long msb, lsb;
	unsigned long data;

	data = f << 2;
	msb = (data >> 14) + 0x4000;
	lsb = (data & 0x00003fff) + 0x4000;

	dds_dataset(0x2000, 16);
	dds_dataset(lsb, 16);
	dds_dataset(msb, 16);
}

/***************************************************************
	interrupt (pin change interrupt)
***************************************************************/
#pragma interrupt isr
#pragma code isrcode = 0x8
void isr_direct(void)
{
	_asm
	goto isr
	_endasm
}
#pragma code
void isr(void)
{
	if(INTCONbits.RABIF) {
		if(PORTBbits.RB5 == 1) {
			if(PORTBbits.RB4 == 0)
				renc_now = 0;
			else 
				renc_now = 1;
		} else {
			if(PORTBbits.RB4 == 1)
				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;
		}
		renc_old = renc_now; 

		INTCONbits.RABIF = 0;
	}
	cflag = 1;
}

/***************************************************************
	long to comma seperater lcd write
***************************************************************/
void long2comma(long data)
{
	int i;
	char buf[10];

	sprintf(buf, "%9ld", data);
	for(i = 0; i < 9; i++) {
		lcd_putch(buf[i]);
		if(i == 2 || i == 5) {
			if(buf[i] != 0x20 && buf[i] != '-')
				lcd_putch('.');
			else
				lcd_putch(' ');
		}
	}
}

/***************************************************************
	lcd write routine
***************************************************************/
void lcd_write()
{
	INTCONbits.GIE = 0;
	lcd_gotopos(0, 0);
	if(mode) { 
		sprintf(tmp, "IF ");
		lcd_putstr(tmp);
		long2comma(offset);
	} else {
		sprintf(tmp, "VFO");
		lcd_putstr(tmp);
		long2comma(freq);
	}
	sprintf(tmp, "Hz");
	lcd_putstr(tmp);

	if(!mode) {
		lcd_gotopos(0, 1);
		if(((freq + offset) > 0) && ((freq + offset) < MAX_FREQ))		
			sprintf(tmp, "DDS");
		else
			sprintf(tmp, "ERR");
		lcd_putstr(tmp);
		long2comma(freq + offset);
		sprintf(tmp, "Hz");
		lcd_putstr(tmp);
	}
	INTCONbits.GIE = 1;
}

/***************************************************************
	main
***************************************************************/
void main(void)
{
	unsigned char sw0_state, sw1_state;
	unsigned int tim0, tim1;
	unsigned int pos;		// cursor position

	OSCCON = 0b11111111;	// 16MHz internal clock

	TRISA = 0b00000000;		// RA4,5 AD9834 serial control
	TRISB = 0b11110000;		// RB4,5 rotary encoder input RB6,7 sw input
	TRISC = 0b00000000;		// LCD and RC5 AD9834 serial control
	ADCON0bits.ADON = 0;	// ad converter off
	UCONbits.USBEN = 0;		// USB disable
	ANSELHbits.ANS10 = 0;	// RB4 digital input
	ANSELHbits.ANS11 = 0;	// RB5 digital input
	ANSELbits.ANS3 = 0;		// RA4 digital input
	ANSELbits.ANS6 = 0;		// RC2 digital input
	INTCONbits.RABIE = 1;	// PortA,B pin change interrupt enable
	INTCON2bits.RABPU = 0;	// PortA,B pull-up enable
	INTCON2bits.RABIP = 0;	// PortA,B interruput priority low
	WPUB = 0b11110000;		// RB4,5,6,7 pull-up
	IOCBbits.IOCB4 = 1;		// RB4 pin change interrupt enable
	IOCBbits.IOCB5 = 1;		// RB5 pin change interrupt enable

	lcd_init();
	lcd_cls();

	sw0_state = sw1_state = 0;
	freq = eeprom_read_long(0);
	offset = eeprom_read_long(1);
	pos = 9;
	mode = 0;
	step = 1000;
	diff = 0;
	tim0 = tim1 = 0;

	if(freq <= 0 || freq >= MAX_FREQ) {
		freq = DEF_FREQ;
		offset = 0;
	}
	if(((freq + offset) > 0) && ((freq + offset) < MAX_FREQ)) {		
		PORTCbits.RC2 = 1;
		freq2serial(freq + offset);
	} else {
		PORTCbits.RC2 = 0;
		freq2serial(0);
	}	

	lcd_putcmd(0x0e);
	lcd_write();

	INTCONbits.GIE = 1;		// general interrupt enable
	cflag = 0;

	while(1){
		
		// step down or press for long time to EEPROM memory write
		if(PORTBbits.RB6 == 0) {
			sw0_state = 1;
			delay_ms(10);
			tim0++;
		}
		if(sw0_state && PORTBbits.RB6 == 1) {
			sw0_state = 0;
			tim0 = 0;
			if(step == 10) {
				step = 1;
				pos = 13;
			} else if(step == 100) {
				step = 10;
				pos = 12;
			} else if(step == 1000) {
				step = 100;
				pos = 11;
			} else if(step == 10000) {
				step = 1000;
				pos = 9;
			} else if (step == 100000) {
				step = 10000;
				pos = 8;
			}
		}
		
		// step up or press for long time to IF setup mode
		if(PORTBbits.RB7 == 0) {
			sw1_state = 1;
			delay_ms(10);
			tim1++;
		}
		if(sw1_state && PORTBbits.RB7 == 1) {
			sw1_state = 0;
			tim1 = 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;
			}
		}

		// frequency and offset write to EEPROM
		if(tim0 > 100) {
			sw0_state = 0;
			tim0 = 0;
			lcd_gotopos(0, 1);
			if(mode == 1) {
				freq = DEF_FREQ;
				offset = 0;
				sprintf(tmp, "Memory Clear!!!!");
			} else 
				sprintf(tmp, "Write to EEPROM!");
			lcd_putstr(tmp);
			eeprom_write_long(0, freq);
			eeprom_write_long(1, offset);
			delay_ms(1000);
			lcd_write();
		}		

		// mode change (mode0: VFO mode, mode1: IF setup mode)
		if(tim1 > 100) {
			sw1_state = 0;
			tim1 = 0;

			if(!mode) {
				mode = 1;
				dds_dataset(0x0040, 16);	// ad9834 sleep
				PORTCbits.RC2 = 0;
				lcd_gotopos(0, 1);
				sprintf(tmp, "IF Setup Mode   ");
				lcd_putstr(tmp);
				lcd_write();
			} else {
				mode = 0;
				lcd_gotopos(0, 1);
				sprintf(tmp, "VFO Mode        ");
				lcd_putstr(tmp);
				if(((freq + offset) > 0) && ((freq + offset) < MAX_FREQ)) {		
					PORTCbits.RC2 = 1;
					freq2serial(freq + offset);
				} else
					PORTCbits.RC2 = 0;
				lcd_write();
			}
			while(PORTAbits.RA5 == 0);
		}

		// frequency changed
		if(cflag) {
			if(!mode) {
				if(diff) {
					if((freq + step) <= MAX_FREQ)
						freq += step;
				} else {
					if((freq - step) >= step)
						freq -= step;
				}
				if(((freq + offset) > 0) && ((freq + offset) < MAX_FREQ)) {		
					freq2serial(freq + offset);
					PORTCbits.RC2 = 1;
				} else {
					PORTCbits.RC2 = 0;
				}
			} else {
				if(diff) {
					if((offset + (long)step) <= MAX_FREQ)
						offset += step;
				} else {
					if((offset - (long)step) >= MIN_FREQ)
						offset -= step;
				}
			}
			lcd_write();
			cflag = 0;
		}
		lcd_gotopos(pos, 0);
	}
}