demo18.c

Hitech microchip PIC C18 Compiler

/**************************************************
 * HI-TIDE PICC-18 Demonstration
 * 
 * Demonstrates LCD, LED's, Push buttons, Switches,
 * Serial I/O
 *
 * Microchip PIC 18C452 Wiring:
 * 
 * 20 x 4 LCD
 *	RS		--> PORTA.3
 *	E		--> PORTA.1
 *	D0		--> PORTD.0
 *	D1		--> PORTD.1
 *	D2		--> PORTD.2
 *	D3		--> PORTD.3
 *	D4		--> PORTD.4
 *	D5		--> PORTD.5
 *	D6		--> PORTD.6
 *	D7		--> PORTD.7
 *
 * Switch  1		--> PORTB.4
 * Switch  2		--> PORTB.5
 *
 * Push Button 1	--> PORTB.6
 * Push Button 2	--> PORTB.7 
 *
 * LED PANEL 1:
 * 	LED0		--> PORTC.0
 * 	LED1		--> PORTC.1
 * 	LED2		--> PORTC.2
 *	LED3		--> PORTC.3
 * 	LED4		--> PORTC.4
 * 	LED5		--> PORTC.5
 *
 * LED PANEL 2:
 * 	LED0		--> PORTC.7
 * 	LED1		--> PORTC.6
 * 	LED2		--> PORTC.5
 *	LED3		--> PORTC.4
 * 	LED4		--> PORTC.3
 * 	LED5		--> PORTC.2
 * 	
 **************************************************/


#include   	<pic18.h>
#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>

#include	"demo18.h"
#include	"delay.h"
#include	"lcd.h"
#include	"serial.h"

/* Scrolling LCD message: */
const unsigned char Message[] =	
			"  ---***** HI-TECH PICC-18 Demostration. *****---  "
			"HI-TIDE can simulate virtual I/O devices for PIC18 "
			"processors running with real-time execution speed on "
			"Windows and Linux!!!   ";

	/* status variables */
volatile unsigned char		status,
				port_stat;
	/* button counter */
signed char			buttons;
	/* switch states */
unsigned char			sw1,
				sw2;

	/* circular serial I/O buffer */
unsigned char	serial_buf[SERIAL_BUFFER+1];
	/* serial I/O buffer head/tail pointers */
unsigned char	serial_head,serial_tail;

/* General initialization of ports, etc... */
void
InitPeripherals(void) {

	WDTCON = 0;
	init_comms();
	printf("\n\n\nStarting HI-TIDE PICC18 demo program...");
	/* configure ports */
	ADCON1 = 0x6;
	
	//set to output bits not used by serial.
	TRISC = 0x80;
	
	TRISD = OUTPUT_DATA;
	PSPMODE = 0;
	LATA = LATB = LATC = LATD = 0;

	TRISA0 = OUTPUT_PIN;
	TRISA1 = OUTPUT_PIN;
	TRISB = 0;
	TRISB4 = INPUT_PIN;
	TRISB5 = INPUT_PIN;
	TRISB6 = INPUT_PIN;
	TRISB7 = INPUT_PIN;

	/* initialize the LCD */	
	lcd_init(EIGHTBIT_MODE);		// Initialize the LCD display

	/* configure timers/interrupts */
	di();
	IPEN	= 0;
	TMR0IP	= 1;		// timer 0
	TMR0IE	= 1;
	TMR0ON  = 1;
	T1CON	&= 0xFD;
	T0CS	= 0;
	INT0IE	= 0;
	
	RBIP	= 0;		// interrupt on PORTB change
	RBIE	= 1;

	RCIP	= 1;		// Serial I/O receive interrupt
	RCIF	= 0;
	RCIE	= 1;
	IPEN	= 0;
	PEIE	= 1;

	printf("OK.\n\n\nType Something.\nIt will be shown on the LCD:\n\nDEMO> ");

	ei();			// start interrupts
}


/* The scrolling message function */
void
MessageFunc(void) 
{
	static unsigned char 		line_buf[LCD_WIDTH+10];
	static unsigned char 		msg_buf[LCD_WIDTH+10];
	static const unsigned char	*msg_ptr = Message;
	unsigned char 			*ptr,count;

	if (!msg_buf[0])		// first time run? clear the buffer
	{

		for (count=0; count < LCD_WIDTH; ++count)
			msg_buf[count] = ' ';		// clear with spaces
	}
	if (CHK_STATUS(SCROLL_MESSAGE))		// time to scroll message?
	{
		for (ptr = msg_buf; ptr < &msg_buf[LCD_WIDTH-1]; ++ptr)
			*ptr = *(ptr+1);
		if (*msg_ptr)				// Add the next character
			msg_buf[LCD_WIDTH-1] = *msg_ptr++;
		else
			msg_ptr = Message;			// end of message, start again
		lcd_goto(MESSAGE_LINE);
		lcd_puts(msg_buf);		// display message on LCD
		CLR_STATUS(SCROLL_MESSAGE);	// message scroll completed
	}
	if (CHK_STATUS(BUTTON_MESSAGE))
	{
		sprintf(line_buf,"Button counter: %d   ",buttons);
		lcd_goto(BUTTON_LINE);
		lcd_puts(line_buf);		// show button count
		CLR_STATUS(BUTTON_MESSAGE);
	}
	if (CHK_STATUS(SW_MESSAGE))		// do we need to update the switch states?
	{
		sprintf(line_buf,"SW 1: %s SW 2: %s",sw1?"ON ":"OFF",sw2?"ON ":"OFF");
		lcd_goto(SW_LINE);
		lcd_puts(line_buf);		// show switch states
		CLR_STATUS(SW_MESSAGE);
	}
}

/* The LED Panel function - shows a flashing LED */
void
LedPanelFunc(void)
{
	static near unsigned char 	flash=0x1;
	static near bit direction;
	
	if (flash & 0x21)		// are we at the end?
		direction = !direction;	// then change direction
	if (direction)
		flash <<= 1;		// shift the 'on' led
	else
		flash >>= 1;
	//leave the two most significant bits of the
	//LED_PANEL unchanged because the are used
	//by the serial i/o.
	LED_PANEL = (LED_PANEL & 0xC0) + ((~flash) & 0x3F);		// display on the LED panel
	CLR_STATUS(LEDS);
}

/* The Push Button Function - Increments or decrements a value depending on
   which button is pressed
 */
void
PushButtonFunc(void)
{

	if (CHK_STATUS(BUTTON_1))	// Was button 1 pressed?
	{
		CLR_STATUS(BUTTON_1);
		++buttons;		// increase the count
	}
	if (CHK_STATUS(BUTTON_2))	// was button 2 pressed?
	{
		CLR_STATUS(BUTTON_2);
		--buttons;		// descrease the button count
	}
	SET_STATUS(BUTTON_MESSAGE);	// now we need to update the LCD message
}


void
SwitchFunc(void)
{
	sw1 = port_stat & SWITCH1;
	sw2 = port_stat & SWITCH2;
	CLR_STATUS(SWITCHES);
	SET_STATUS(SW_MESSAGE);
}


void interrupt 
ISR(void)			//	The main ISR routine
{
	if (TMR0IE && TMR0IF)		// did the timer cause the interrupt?
	{
		SET_STATUS(SCROLL_MESSAGE | LEDS);
		TMR0 = 0xF000;
		TMR0IF = 0;
	}
	if (RBIE && RBIF)		// did something on PORTB change?
	{
		port_stat = PORTB;
		if (port_stat & BUT1)		// was button 1 pressed?
			SET_STATUS(BUTTON_1);
		else if (port_stat & BUT2)	// was button 2 pressed
			SET_STATUS(BUTTON_2);
		else				// a switch must have changed
			SET_STATUS(SWITCHES);
		RBIF = 0;
	}
	if (RCIE && RCIF)		// did we receive serial I/O
	{
		SET_STATUS(SERIAL_REC);
		serial_buf[serial_head] = RCREG;		// add to circular buffer
		serial_head = (serial_head +1) % SERIAL_BUFFER;
		RCIF = 0;
	}
}

/* The serail I/O function */
void
SerialFunc(void)
{
	char ch;
	char serial_msg[LCD_WIDTH+1];
	
	ch = serial_buf[serial_tail];
	serial_tail = (serial_tail + 1) % SERIAL_BUFFER;
	putch(ch);		// echo the typed character
	if (ch == '\r')		// was ENTER pressed? ->clear buffer, display prompt
	{
		printf("\nDEMO> ");		// display a prompt
		for (ch=0; ch < SERIAL_BUFFER; ++ch)	// clear buffer
			serial_buf[ch] = ' ';
		serial_head = serial_tail = 0;
	}
	lcd_goto(SERIAL_LINE);
	sprintf(serial_msg,"Serial:%s",serial_buf);
	lcd_puts(serial_msg);
	CLR_STATUS(SERIAL_REC);
}

void
main(void)
{

	InitPeripherals();		// initialize peripherals
	status = 0xff;
	CLR_STATUS(SERIAL_REC);
	while(1)
	{
		if (CHK_STATUS(BUTTON_1 | BUTTON_2))		// was a button pressed?
			PushButtonFunc();
		if (CHK_STATUS(SWITCHES))			// did the switches change state?
			SwitchFunc();
		if (CHK_STATUS(LEDS))				// time to update leds?
			LedPanelFunc();
		if (CHK_STATUS(SCROLL_MESSAGE | BUTTON_MESSAGE | SW_MESSAGE))	// time to update LCD?
			MessageFunc();
		if (CHK_STATUS(SERIAL_REC))			// did we receive serial data?
			SerialFunc();
	}
}