Help! something in this code causes reset

[Sophi]

HI- I am using a P40 Olimex protoboard with an LCD and an RC servo wired to it. The RC servo has three wires, +5, gnd and signal which is wired to pin 34 (B1) of a 16F877A. I have written a simple loop program for the servo to go counterclockwise then clockwise. The trouble is that the program restarts/resets itself after it executes...and printing the index k to the LCD shows that k=0. If I comment out the
line:for (k=0; k<=5; ++k){ and its corresponding } the program goes to the end and stops, so somehow looping this is causing a reset. I have tried switching out this k loop for a do-while with the same result.
And the servo wire pin 34 is not wired to anything else- it is empty on the Olimex schematic.
Finally-the program with the loop works fine when the variable delay (x and y) is removed by putting the actual numbers in, and k prints as 5, so I would also conclude that the variable delay is making my program hokey.
Any ideas?
Thanks-
Sophi

main()
{
int i = 0;
int k = 0;
float volt = 1;
float ad12; // output of a/d
int x,y;
set_tris_a(0b00100000); // sets port a direction 0=out 1=in
set_tris_b(0xF0); // set B4-7 to output
// and B0-3 inputs
init:
lcd_init();
adc_init();
output_high (PIN_A0); // start init test circuit routine
lcd_putc("\fCode 6\n");
delay_ms (1000);
output_low (PIN_A0); // turn LED off
delay_ms (1000);
output_low (PIN_B1); // servo out

// servo CC and CCW full range
for (k=0; k<=5; ++k){
for (i=1; i<=100; ++i)
{
output_high (PIN_B1); // servo out high 1000 us is CW
delay_us (2000);
output_low (PIN_B1); // servo out (off)
delay_us (19000);
}//end of for

for (i=1; i<=100; ++i)
{
x = 1200;
y = 22000;
output_high (PIN_B1); // servo out high 1200 us using variable is CCW
delay_us (x);
output_low (PIN_B1); // servo out (off)
delay_us (y);
}//end of for
printf(lcd_putc,"%d" ,k);
k++;
}
}

[PCM programmer]

I didn't try to analyze your code, but normally you don't do nested
loops like that. The loop counter is normally incremented in its
for() statement, like this:

[Sophi]

thanks PCM-
Do you mean k++ instead of ++k? Or something else.
Sophi

[Sophi]

I can't believe it, by switching to k++, it works! Well, at a pretty slow speed but no more jumping out of the loop.
Thanks so much!

[PCM programmer]

[Sophi]

OK. extra k++ has been removed.
I spoke too soon about the code working tho. It seems only to work when I switch to delay_ms rather than delay_us, and then the servo motor moves really really slow. Wierd. Any ideas?
And how do I post code in the code box?
Sophi

main()
{
int i = 0;
int k = 0; // loop count
float volt = 1;
float ad12; // output of a/d
float x,y;
set_tris_a(0b00100000); // sets port a direction 0=out 1=in
set_tris_b(0xF0); // set B4-7 to output
// and B0-3 inputs
init:
lcd_init();
adc_init();
output_high (PIN_A0); // init test circuit routine
lcd_putc("\fCode 7\n"); // welcome
delay_ms (1000); //
output_low (PIN_A0); // turn LED off
delay_ms (1000);
output_low (PIN_B1); // servo out
// servo CC and CCW full range
for (k=0; k<=5; k++){
for (i=1; i<=100; i++)
{
output_high (PIN_B1); // servo out high 1000 us is CCW
delay_us (2000);
output_low (PIN_B1); // servo out (off)
delay_us (19000);
lcd_putc("\fCCW\n"); // welcome
} //end of for
for (i=1; i<=100; i++)
{
x = 1.20; //this loop makes the servo move really really slooow
y = 2.20;
output_high (PIN_B1); // servo out high 1200 us using variable is CCW
delay_ms (x);
output_low (PIN_B1); // servo out (off)
delay_ms (y);
lcd_putc("\fCW\n"); // welcome
}//end of for
printf(lcd_putc,"%d" ,k);
}
}

[Sophi]

oops- y = 22.0

[PCM programmer]

You need to read the manual on all the CCS functions that you
are using. You are doing some things that are not allowed.

If you read the CCS manual on the delay_us() and delay_ms()
functions, you will see that there are strict limits on the parameters.

You cannot use floating point parameters.

You cannot use 16-bit variables as parameters, only 8 bits.

If you want a 16-bit parameter, it must be a constant.

You must read the manual.

[Sophi]

OK.
thanks-

[drh]

Also, this

[Humberto]

Sophi wrote:

[Sophi]

OK I read the manual. Rules are clear.
Variables (us or ms) only 0-255
Constants (us or ms) only 0-65535
Seems to indicate no floats.

I need a 2 variables in us #1 is 1000-2000, the other 22000 minus variable#1. OR a float that is ms 1-2, the other (22-#1). The last three places are the important ones.
To be clear an example of this would be variable #1 is something like 1200us and variable #2 is 20800us.
Can I alter the delay function? And if so, where can I find it?
Should I write my own delay function or are there other built in delay functions? And if so, would I still use

[Guest]

For all those interested, I found this link - haven't tried it yet:
http://www.ccsinfo.com/forum/viewtopic.php?t=16656[/url]

Sophi