I don't understand this code!

[Russ Kincaid]

I re-wrote the program to produce the opposite waveform, but it is the same waveform:
LOW GPIO.0 'INITIAL CONDITIONS
LOW GPIO.1

START:
HIGH GPIO.1
PAUSEUS 4168 ' HIGH TIME
LOW GPIO.1
PAUSEUS 4167 'DEAD TIME, BOTH LOW
HIGH GPIO.0 'SETS PIN 7 HIGH
PAUSEus 4168 'FOR 4.168 MILLISECONDS
LOW GPIO.0
PAUSEUS 4167 'DEAD TIME

GOTO START '60 HZ FREQUENCY

END

Since both programs produce the same waveform, I guess my only option is to turn the LEDs around!
My circuit is only for testing. If I were driving solid state relays they would burn up when both were on.

[Pic_User]

Russ, the code will cause both LEDs to be on at the same time, even if the LEDs are referenced to ground.
GPIO.0 and GPIO.1 are the same level in the “second” and the “forth” time increment.
The previously attached waveform drawing shows this.
http://www.picbasic.co.uk/forum/atta...1&d=1178466510
You may have forgotten 4.168 milliseconds is one quarter (“one quadrant”) of a full cycle (16.667) – not one half.
-Adam-

[skimask]

Might sound a bit silly, but, maybe if you drew us a quick picture of what you want the output to be, like if it was a picture from an o'scope, we might be able to better understand what you actually want.
The last post by Pic_User sounds like that might be the problem, simple mistake, easily fixed...

[Russ Kincaid]

The waveform posted by Picuser is what I want the output to look like. The actual output is the inverse and I don't understand it. Perhaps my compiler is corrupted?

[skimask]

The waveform posted by Picuser is what I want the output to look like. The actual output is the inverse and I don't understand it. Perhaps my compiler is corrupted?

I'd highly doubt your compiler is corrupted, but maybe a reinstall is in order.
And I think post #16 might be your problem in the first place.

[Russ Kincaid]

Thanks for your reply. PIC_USER is correct in post #16, both GPIO.0 and GPIO.1 are at the same level in time periods 2 and 4, but they are both low. I want them to be high. Can someone tell me what is wrong with my code?

BTW, I changed to TRISIO=0, didn't make a difference.

[Pic_User]

Hi Russ,
I think with your original pins (GPIO.0 and GPIO.1), and your second (inverse) code:

LOW GPIO.0 'INITIAL CONDITIONS
LOW GPIO.1

START:
HIGH GPIO.1
PAUSEUS 4168 ' HIGH TIME
LOW GPIO.1
PAUSEUS 4167 'DEAD TIME, BOTH LOW
HIGH GPIO.0 'SETS PIN 7 HIGH
PAUSEus 4168 'FOR 4.168 MILLISECONDS
LOW GPIO.0
PAUSEUS 4167 'DEAD TIME

GOTO START '60 HZ FREQUENCY

END

...and your diodes reversed and the resistor tied to ground (as skimask said).

Your two LEDs will not be on at the same time... (try it)

I still would like to know between which points are you measuring the wave (voltage) from?

-Adam-

[Russ Kincaid]

Hi Pic_User. Yes, I know that, but why cannot I connect the LEDs to + and pulse to ground? I changed the program, trying to zero in on the probem. Now GPIO.1 pulses to ground like I want but GPIO.0 pulses positive in phase with GPIO.1. I would not expect GPIO.0 to change at all.

high GPIO.0 'INITIAL CONDITIONS
high GPIO.1

START:
low GPIO.1
high GPIO.0
PAUSEUS 4168 ' ON TIME
high GPIO.1
PAUSEUS 4167 'DEAD TIME, BOTH high
high GPIO.1
PAUSEus 4168 'FOR 4.168 MILLISECONDS
high GPIO.1
PAUSEUS 4167 'DEAD TIME

GOTO START '60 HZ FREQUENCY

END

I will post the final circuit so you can see what I am trying to do. I want to replace the 555, flip flops and gate with the PIC.