Search found 15 matches

thx a lot. I've got it working now!

I do have to increase my crystal frequency from 20MHz to 40MHz though. For some reason, my 40MHz isn't giving me 40MHz on the CRO, but rather, 13.6MHz. So I'm ...

polling an interrupt flag without enabling it?

do you mean, I can poll it by creating a tight loop checking for the interrupt flag bit toggling? I've never thought of this method but it's definite ...

woah Ttelmah,

thanks a lot for the reply.

I think your calculation of the instruction cycle is correct but the crystal is fine. 38.3 Hz is the frequency of the complete square pulse that the ti ...

sorry, I didn't clear my test program enough for you guys. Being lazy is perfectly fine. Everyone should be lazy. :P

I've updated the program above, removed garbage etc.

anyway, I tested the ...

I've been scratching my head for ages and hair's everywhere... What's the highest frequency for this damn timer?

for 18F4431, timer1 is a 16bit timer. The highest I've got is 22.5KHz... My 16F88 ...

put this to your 18F4431.h file

//setting QEI

#define DISABLE_VELOCITY 0x80
#define QEI_OFF 0x00
#define QEI_2XINDX 0x04
#define QEI_2XPER ...

thanks a lot RLScott!

I have one last question.

is it possible to set up the hardware PWM off of a 18F4431 and set it to single shot mode to do that?

I've encountered problems with the single ...

How do you setup the PWM single shot function to do data transmission?

I figured I've to use the int_PWMTB interrupt, but how do I re-enable the function and have it fire again?

I'm trying to op ...

hello briany
You mean one for up and other for down counting
regards
satish

no, I mean both on rising edge counting. but CCP1 for signal A, and CCP2 for signal B.

I've never tried it, but the idea's been in my head for a bit.

What I was thinking is:

since quad encoders rely on the phase diff to differentiate the direction, you can have signal A connected ...

He didn't mean switch to Timer2. He meant you should use the PWM
module in the PIC.

See this thread for the PWM frequency formula and code to setup
the PWM controller.
http://www.ccsinfo.com ...

Setting Timer 0 has nothing to do with the frequency with which Timer 0 interrupts occur. You call set_timer0() just once during setup. From that point on, Timer 0 counts up and overflows from 0xff ...

I think you can.

1 using the QEI function, and the other one using CCP1 and CCP2.

then I think you have to write the code for the CCP part.

int round(float fl)
{
float r = fl - floor(fl);
if (r >= 0.5)
return((int)ceil(fl));
else
return((int)floor& ...

hi all,

I'm trying to create a PPM ultrasonic pulse at 200KHz using timer0. So, what it's in my mind is:

- provide a character
- use timer0 as a counter to toggle a pin high and low until t ...