f_12_10_adc_ser.c

* Use 10 MHz crystal frequency. * Use Timer0 for ten millisecond looptime. * Blink "Alive" LED e

// For MCC18, this file uses the -Oi flag, which
// turns on integer promotions so that (ADRESH << 8) works.

#include        "config.h"
#include        "delay.h"
#include        "serial.c"
#include        "serio.c"
#include	"jwb.h"

/*
 * program to read ADC on RA5 and display a bar graph on LCD module
 */

void	init(void);
void	char2hex(unsigned char c, unsigned char *s);
void	int2hex(int c, unsigned char *s);
void	Adc2Hex(int c, unsigned char *s);
void	SelectAdcChannel(unsigned char c);
unsigned char		ReadPot(void);
int		ReadTemp(void);
int		ReadAdcChannel(unsigned char c);


extern void serial_init (char brg, char hi_speed);

const unsigned char MESSAGE1[]	=	"turn pot";
unsigned char str1[9];
unsigned char str2[9];

void main(void)
{
	int					val0, val1;
	char				i;
	unsigned char		c;

	double				dval0, dval1;

	for (i=8; i<=0 ;i-- ) {
		str1[i] = 0;
		str2[i] = 0;
	}

	init();

	printf("Hit any key to read ADCs...");  pcrlf();

	while(1)
	{
		c = getch();

		//TOGGLE(LED2);

		if (c=='q')
		{
			for (i=0; i <5; i++)
				printf("%d->%4d   ", i, ReadAdcChannel(i) );
			pcrlf();
		}
		else
		{
			val0 = ReadAdcChannel(0);
			val1 = ReadAdcChannel(1);
			dval0 = 5.0 * val0 / 1024;		// convert AN0 value to float (assume Vdd=5V)
			dval1 = 5.0 * val1 / 1024;		// convert AN1 value to float
			printf("AN0=%4d (%1.3fV)     AN1=%4d (%1.3fV)", val0,dval0,val1,dval1);
			pcrlf();
		}
	}
}

// initialize
void init(void)
{
	PORTA = 0x00;
	ADCON0 = BIT7|BIT6|BIT0;								// internal ADC oscillator + ADON
	ADCON1 = BIT6|0x4;										// L.just, AN0+AN1+AN3, no ext REFs

	SET_AS_INPUT(TRISA, BIT0 | BIT1);						// inputs for Two ADC channels


	PORTB = 0x00;
	SET_AS_OUTPUT(TRISB, BIT0 | BIT1 | BIT2 | BIT3 | BIT4 | BIT5 );		// set RB0-RB5 to output
	// recall that RB6 and RB7 are reserved for the HW programmer/debugger

	PORTC = 0x00;
	SET_AS_OUTPUT(TRISC, BIT0 | BIT1 | BIT2 | BIT3 | BIT4 | BIT5);		// RC0,RC3,RC5 drive DAC
	// RC6 and RC7 are used in serial UART, so leave them alone

	// initialize the serial port

	serial_init(95, 1);			// setup 19200 baud serial IO w/ Fosc=29.4912MHz

}

int		ReadAdcChannel(unsigned char c)
{
	unsigned char	temp;
	
	temp = ADCON0 & (BIT7|BIT6|BIT0);	// clear bits except ADCS1:ASCS0 and ADON
	ADCON0 = temp | ((c & 0x7)<<3);		// select the desired ADC channel and write to ADCON0
	DelayUs(20);						// wait 20us for ADC to get ready
	GODONE = 1;							// start ADC conversion
	while(GODONE);						// then wait for ADC to finish
	if ( ADFM )
		return ((ADRESH * 256) | ADRESL);
	else
		return ((ADRESH << 2) | (ADRESL>>6) );
}


void	SelectAdcChannel(unsigned char c)
{
	unsigned char	temp;
	
	temp = ADCON0 & (BIT7|BIT6|BIT0);	// clear bits except ADCS1:ASCS0 and ADON
	ADCON0 = temp | ((c & 0x7)<<3);		// select the desired ADC channel and write to ADCON0
}

// ReadPot assumes that the ADCON1 has the RA5/AN4 channel configured as
//    an ADC input
unsigned char ReadPot(void)
{
	SelectAdcChannel(4);		// pot is connected to RA5/AN4
	DelayUs(20);				// wait 20us for ADC to get ready
	GODONE = 1;					// start ADC conversion
	while(GODONE);				// wait for GODONE to low
	return (ADRESH);			// just return the MSB
}

// ReadPot assumes that the ADCON1 has the RA0/AN0 channel configured as
//    an ADC input
int ReadTemp(void)
{
	SelectAdcChannel(0);		// temp sensor is located on RA0/AN0
	DelayUs(20);				// wait 20us for ADC to get ready
	GODONE = 1;					// start ADC conversion
	while(GODONE);				// wait for GODONE to low
	return ((ADRESH << 2) | (ADRESL>>6) );
}

void Adc2Hex(int c, unsigned char *s)
{
	unsigned char tmp;

	tmp = (c >> 8) & 0x0F;
	// first hex digit
	if (tmp >= 10)
		tmp += 0x37;
	else
		tmp += 0x30;
	*s = tmp;
	// next two hex digits
	tmp = c & 0xFF;
	char2hex( tmp, s+1);
}

void int2hex(int c, unsigned char *s)
{
	unsigned char tmp;

	tmp = c >> 8;
	char2hex( tmp, s);
	tmp = c & 0xFF;
	char2hex( tmp, s+2);
}


void char2hex(unsigned char c, unsigned char *s)
{
	unsigned char tmp;

	tmp = c >> 4;
	// first hex digit
	if (tmp >= 10)
		tmp += 0x37;
	else
		tmp += 0x30;
	*s = tmp;
	s++;
	// second hex digit
	tmp = c & 0x0F;
	if (tmp >= 10)
		tmp += 0x37;
	else
		tmp += 0x30;
	*s = tmp;
}