Administrace komentářů

//      radsi to zatim nigdo nezkousejte naostro, pac chybi:
//      -dopsat delay v mereni()
//      -dodelam jak budu mit chut, sith @ wifistar . net

#include < stdio.h>
#include < fcntl.h>
#include < termios.h>
#include < sys/ioctl.h>
#include < time.h>

#define SERIAK "/dev/ttyS1"

void power (unsigned short level);
int openserial ();
void closeserial ();
void RTS (unsigned short level);
void DTR (unsigned short level);
int CTS ();
float mereni ();

int fd;

void
power (unsigned short level)	//napajeni pro prevodnik
{
	int status;

	ioctl (fd, TIOCMGET, &status);
	if (level == 0)
		ioctl (fd, TIOCSBRK, &status);
	else
		(fd, TIOCCBRK, &status);

	ioctl (fd, TIOCMSET, &status);

}

int
openserial ()			//otevrit seriak
{
	if ((fd = open (SERIAK, O_RDWR)) == -1)
	{
		return 0;
	}
	return 1;
}

void
closeserial ()			//zavrit seriak
{
	close (fd);
}

void
RTS (unsigned short level)	//nastav stav RTS
{
	int status;

	ioctl (fd, TIOCMGET, &status);

	if (level)
	{
		status |= TIOCM_RTS;
	}
	else
	{
		status &= ~TIOCM_RTS;
	}

	ioctl (fd, TIOCMSET, &status);
}

void
DTR (unsigned short level)	//nastav stav DTR
{
	int status;

	ioctl (fd, TIOCMGET, &status);
	if (level)
	{
		status |= TIOCM_DTR;
	}
	else
	{
		status &= ~TIOCM_DTR;
	}

	ioctl (fd, TIOCMSET, &status);
}

int
CTS ()				//stav CTS
{
	int status;

	ioctl (fd, TIOCMGET, &status);
	//ioctl (fd, TIOCMIWAIT, TIOCM_CTS);

	return (status & TIOCM_CTS);
}

void
wait (int wait)			//cekej x ms
{
	int cas;
	clock_t start, end;

	wait *= 0.001;

	start = clock ();

	do
	{
		end = clock ();

		cas = end - start;
	}
	while (cas < (CLOCKS_PER_SEC * wait));
}

float
mereni ()			//hlavni fce, mereni napeti
{
	RTS (1);		//CS

	int status, bity = 128, cas = 0, hodnota = 0, i;	//bity tzn jake rozliseni ma prevodnik 2^x
	float mereni = 0.0;

	wait (20);		//x msec

	RTS (0);		//CS

	for (i = 0; i < 8; i++)	//konecne hot stuff ;)
	{
		if (CTS ())
			hodnota += bity;

		DTR (0);	//clock

		DTR (1);	//clock

		bity /= 2;

		wait (20);
	}

	return (mereni = (float) hodnota / 50.0);
}

int
main ()
{
	float napeti = 0.0;
	short unsigned i;

	if (!openserial ())
	{
		printf ("Nelze inicializovat port \"s\".", SERIAK);
		return 0;
	}
	power (0);		//txd break on

	wait (10);

	DTR (0);		//clock

	RTS (0);		//CS

	wait (10);

	for (i = 0; i < 40; i++)
	{
		napeti += mereni ();
	}

	wait (10);

	napeti = (napeti * 1000) / i;

	printf ("\r%d mV", (int) napeti);

	power (1);		//txd break off

	closeserial ();

	return 0;
}