Trouble with Keil programming

[Jack// ani]

Hi all,

What could be wrong with this one, not working at all. And please tell me how to calculate time delay.

#include <AT89S8252.h>

void wait (void)
{
;
}

void main( void )
{
unsigned int i;

P1 = 0;

while(1)
{
P1=1;
for (i=0;i<10000;i++)
{
wait();
}
P1=0;
}
}


Thanks

 

[marifhossain]

your wait() function is not detailed. there may be some problem. And if it is blank, I see a ; in it. Otherwise it seems ok!

 

[Jack// ani]

Trouble with ke*il programming

I got the Keil codes form somewhere and modified it a little. Wait function was carrying ; there also! If it is wrong then please give me the correct code? What about time delay?

 

[gujm1]

Trouble with ke*il programming

Why not use the timer for delay? I recommend my solution in actual project. I use a timer to compute the delay. set the controller to power saving mode. if the timer decrease to 0, trigger the timer interrupt serving code, which is a return. and return to the next instruction of the main program.

 

[svicent]

Your code is OK.

The problem (and the solution), I think is:

1º) You write P1 = 1;
2º) You waste some time (for loop)
3º) You write P1 = 0;
4º) Repeat 1-3: You write P1 = 1:

Step 3 (P1 = 0) is very short because immediately you write P1=1. You must include another for loop after step 3.

Regards, svicent

 

[mrcube_ns]

You dont need wait func at all, inthis case I aways use this:

for (i=0;i<10000;i++)
{
}

Program counting i from 0 to 10000, so you made wait func, witout wait func.

Should you consider to use interrupts for waiting (in serious aplications), couse your program will stop in that point untill i rich 10000, so everything else will be stoped for that time.

Mr.Cube

 

[Jack// ani]

Trouble with ke*il programming

Thanks for suggestion, still this doesn’t solves my problem. My hardware is working fine, and problem seems to be on the software side. Here is the hex which I get after compilation

:01002B0022B2
:10000300E4F590759001E4FFFE12002B0FBF000191
:0C0013000EBE27F5BF10F2E4F59080E768
:0300000002001FDC
:0C001F00787FE4F6D8FD7581070200032D
:00000001FF

Whats the problem?

 

[UroBoros]

hai
Hope you have added a wait after clearing the port to 0 also.

Instead of HEX check the disassembly window in keil and see how the code is compiled and see if programe is ok in simulator.
How the output is now?
Picstudent

 

[mrcube_ns]

Picstudent get the point,


you have just a few cycles where are P1=0, so its always 1.

If you have osciloscope you can see that, and we are all blind, just add one more wait after P1=0.


Mr.Cube