#include <p18F452.h>
#include <delays.h>
#include <stdio.h>
#include <usart.h>

/* Set up the configuration bits */
#pragma config OSC = HS
#pragma config PWRT = OFF
#pragma config BOR = OFF
#pragma config WDT = OFF
#pragma config LVP = OFF

#define HIGH_LIMIT 200
#define LOW_LIMIT 80

// This program switches on the LED when the value read by the
//  A/D module is between LOW_LIMIT and HIGH_LIMIT.

void usart_setup(void)
{
	/* Configure all PORTB pins for output */
  	TRISB = 0;
	
  	/*
   	 * Open the USART configured as
   	 * 8N1, 9600 baud.
   	*/
  	OpenUSART (USART_TX_INT_OFF &
    	       USART_RX_INT_OFF &
               USART_ASYNCH_MODE &
               USART_EIGHT_BIT &
               USART_SINGLE_RX &
               USART_BRGH_HIGH, 129);

}

void io_port_setup(void)
{
	// RE2 for input and RE1 for output;
	TRISE = 0b00000100;

	// RE1 (LED) is on;
	PORTE = 0b00000010;

	// RA0 for input;
	TRISA = 0b00000001;

	// Select AN0 as Anolog and AN6/7 (RE1/2) as digital
	// We are using the internal reference (VDD)
	// PCFG3:0 = 0010
	ADCON1 = 0b00001001;

	// Result is left aligned in ADRESH
	ADCON1bits.ADFM = 0;

	// Conversion clock set to Fosc/32 (ADCS2:0 = 010)
	// Fosc = 20Mhz
	ADCON1bits.ADCS2 = 0;
	ADCON0bits.ADCS1 = 1;
	ADCON0bits.ADCS0 = 0;

 	// We are sampling AN0: CHS2:0 = 000
	// ADCON0 = ((ADCON0 & 0b11100011) | 0b00000000);
	ADCON0bits.CHS2 = 0;
	ADCON0bits.CHS1 = 0;
	ADCON0bits.CHS0 = 0;

	// Powering the module
	ADCON0bits.ADON = 1;

	// acquisition delay?

	// Starting the fist conversion
	ADCON0bits.GO = 1;
}

void main( void)
{
	// setup the ports
	io_port_setup();

	// setup the USART
	usart_setup();

	// Loop forever
	while (1)
	{
		while (ADCON0bits.GO == 1); // conversion in progress
		if ((ADRESH > HIGH_LIMIT) || (ADRESH < LOW_LIMIT))
		{
			PORTEbits.RE1 = 0;
		}
		else
		{
			PORTEbits.RE1 = 1;
		}

		// print the current value
		printf("Current value: %d     \r", ADRESH);

		// aquisition delay?

		// Start a new conversion
		ADCON0bits.GO = 1;		
	}
}