Thread: Drawing waveform using turbo c not prefect!!

Hello,
I am trying to draw a wave form using turbo c .. I am reading voltage input using an ADC card and plotting the voltage from -10 to +10 .. the code works fine, but the line of program drawn goes out of the borders vertical axis if I change the parameters? I was wondering if there is a way to limit the vertical line drawn so it doesn't go beyond the the table setup by the program? I don't have a problem with the horizontal axes.
here is the full code that I wrote:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <graphics.h>

#define DAQ1 0x0300  //Channel 1 ADC card

//******************//
// Global variables //
//******************//

int graphdriver = DETECT,
    graphmode,
    linein,dev,xaxis,yaxis,key,time;

unsigned int data,data1,data2;
float Constant = 546.133,zeroline=190;

//***************//
//     functions   //
//***************//
void Display (void)
{
cleardevice();
   
   setcolor(14);
   outtextxy(20, 260, "Please use the following keys:");
   setcolor(RED);
   outtextxy(30, 270, "Channel 1");
   outtextxy(30, 280, "Q=5    V/Div");
   outtextxy(30, 290, "W=2    V/Div");
   outtextxy(30, 300, "E=1    V/Div");
   outtextxy(30, 310, "R=0.5  V/Div");
   outtextxy(30, 320, "T=0.2  V/Div");
   outtextxy(30, 330, "Y=0.1  V/Div");

   settextstyle(0,0,0);
   setcolor(8);
   outtextxy(5,460, "Press Esc to exit");
   outtextxy(330, 460, "Copyright (C) 2011 Mohammed Almualla");

for(dev=50;dev<530;dev=dev+6)
	{
       setcolor(8);
	line(dev,10,dev,250);
	}

for(dev=10;dev<255;dev=dev+6)
	{
	setcolor(8);
	line(50,dev,530,dev);
	}


setcolor(GREEN);
for(yaxis=10; yaxis<260; yaxis=yaxis+30)
	{
	line(50,yaxis,530,yaxis);
	}
for(xaxis=50; xaxis<550; xaxis=xaxis+30)
	{
	line(xaxis,10,xaxis,250);
	}
}     

void waveform (void)
{
float SaveData;

outport(DAQ1);
delay(1);
data=inport(DAQ1);

SaveData =data/Constant;
data2=zeroline- SaveData;

setcolor(YELLOW);
for(linein=50; linein<541; linein++)
	{
	outport(DAQ1);
	delay(1);
	data=inport(DAQ1);
	
	SaveData =data/Constant;
	data2=zeroline- SaveData;

	line(linein,data1,linein,data2);

	data1=data2;
	}                        
}

//***************//
//  main Program //
//***************//
void main (void)
{
initgraph(&graphdriver,&graphmode,"c:");

for(;;)
	{
	if (!kbhit())
		{
		Display ();
		waveform ();
		}
	else
		{
		key=getch();
		switch(key)
			{
			case 'q':case 'Q':
			Constant=546.133;
			zeroline=190;
			break;

			case 'w':case 'W':
			Constant=218.45;
			zeroline=280;
			break;

			case 'e':case 'E':
			Constant=109.22;
			zeroline=430;
			break;

			case 'r':case 'R':
			Constant=54.6125;
			zeroline=730;
			break;

			case 't':case 'T':
			Constant=21.8453;
			zeroline=1630;
			break;

			case 'y':case 'Y':
			Constant=10.9226;
			zeroline=3130;
			break;


			case 27:
				closegraph();
				exit(0);
				break;
			}
		}
	if (key==27)
	break;
	}
}

can't figure out how to limit the vertical axes on the line!

What's the point of using code tags, but not indenting?


Quzah.

Code:

void Display (void)
{
cleardevice();

for(dev=50;dev<530;dev=dev+6)
{
setcolor( 8 ) ;
line(dev,10,dev,250);
}

for(dev=10;dev<255;dev=dev+6)
{
setcolor( 8 ) ;
line(50,dev,530,dev);
}

That's what you did.

Code:

void Display (void)
{
    cleardevice();

    for(dev=50;dev<530;dev=dev+6)
    {
        setcolor( 8 ) ;
        line(dev,10,dev,250);
    }

    for(dev=10;dev<255;dev=dev+6)
    {
        setcolor( 8 ) ;
        line(50,dev,530,dev);
    }

That is indented. See how purdy mine is and how ugly yours is?

Also, you have a whole slew of functions you aren't showing us here (such as how line actually works).


Quzah.

Not really, since it doesn't tell us anything about what the arguments are. If you want say, 6 vertical steps max, drawing a vertical diagonal, then you need to make sure your math works in six steps.

Code:

int line( int startx, int starty, int endx, int endy, int vsteps, int hsteps )
{
    int width = endx - startx,
        height = endy - starty,
        row = 0, col = 0;
    for( width /= vsteps, row = starty; row < endy; row += width )
        for( height /= hsteps, col = startx; col < endx; col += height )
        {
            gotoxy( col, row );
            putc( 'x' );
        }
}

Or something like that. It's the general idea, I might have mixed up a couple of axes in the middle of that, but that's the general idea of what you want to do. Or at least that's what I think you are trying to do.


Quzah.

I see your point, but I an trying to draw a line (wave form) emulating an oscilloscope on the screen and I'm reading my input from the ADC card on the PC and I want to limit the line drawn vertically if I change the oscilloscope setting say from 5 volts per devision to 1 volts per devision? I hope this gives you a more clear idea.

Is DOS your real operating system?

If you're running this TurbidCrap inside the DOS emulation of windows, then you're only going to have access to emulated I/O ports as well. Now whether those ports are just faked, or mapped to the real ports under supervision of the real OS is likely to be a guess at this point. It would certainly require a lot more research to make sure the emulation was capable of doing what you want.

The next huge problem is this
> #define DAQ1 0x0000 //Channel 1 from ADC card
Ralf Brown's Files
According to this information, port 0 is channel 0 of the first DMA controller.

> outport(DAQ1);
I thought the outport functions had two parameters, the second being the value you want to output on the port.



The much better alternative is to just put the crap in the bin, join the rest of the world in this millennium. and get a real compiler for your real OS.

> Yes Dos is my real operating system.
OK, so your compiler choice is at least a sensible one then. 99% of people who come here using TC are running it on top of XP or later.

You should really find out what port(s) your ADC card really reside.
Poking around at random in the I/O space of a PC is a good way of crashing the whole machine.

It makes a difference, because you're posting only something which "looks like your code" as opposed to being "your actual code". Otherwise, we all spend a few wasted days going over things which have no relevance to your actual problem.

Like the outport() thing, which also looks paraphrased.
IIRC, the names of the routines were outportb() and outportw(), depending on whether you were outputting a byte or a word.

TBH, if your next post isn't your actual code, with corrected outport() calls, then I'll probably just ignore you as being too much effort