Help with Pic Delay Pulse code please

[Chris Barron]

You don't know whats going on?? I wish I knew..

The only thing I keep going back to is the resistors,,,
By the way the i/p is being driven via an opto isolator (it seems to be a clean 5v to 0v switch)

Cheers
Dave..

Dave, do you really need to invoke the WDT ?
Also, I have had problems with the MCLR define (in MPLAB, not picbasic) working inversely. When set to off it needed a pullup ! Bizarre


Chris

[Melanie]

Make a girl work why don't you!

1. I downloaded the Repeater.TXT file from the forum and renamed it Repeater.BAS

2. I compiled it with PBP 2.46

PBP -p12F675 Repeater -v

3. I drew the test schematic and posted it here

4. I breadboarded it

5. I tested it

6. I documented it



It works as expected thus...

A. When SW2 is pressed OUTPUTLINE illuminates along with DELAYLED.

B. If SW2 is released within one Second, DELAYLED and OUTPUTLINE still remain illuminated until one Second expires - then both go out.

C. If SW2 is held beyond one Second, DELAYLED goes out at the one Second count, but OUPUTLINE remains illuminated for as long as SW2 is held. The instant SW2 is released OUTPUTLINE goes out.

D. If SW2 is pulsed within it's initial one Second period, both DELAYLED and OUTPUTLINE remain illuminated (and the one Second count keeps being reset) until the pulsing stops. Thereafter either condition B or C will apply.

E. If SW1 is pressed, all LEDS go out - including BLINKY until SW1 is released.

F. BLINKY tells you you've paid your electricity bill unless condition E applies.



If yours don't work like that then...

1. Breadboard my test schematic and run it...

2. Check your Supply +5v is good... (you don't need anything on your MCLR pin unless your programmer isn't programming the CONFIGS properly).

3. Check your INPUTTRIGGER with a scope... is it waving about keeping the DELAYTIME (DELAYLED) running (per condition D above)? This is the ONLY thing that I can think of immediately that would cause your PIC to malfunction the way you describe.

[g7jiq]

Hello again,

Sorry to put you to all this, Its very much appreciated.

I have run up the circuit as your diagram,
I think I may be on the right trail of the problem.
As you have it it does nothing,
I have to add a pullup 4k7 to the MCLR pin, like on the 16F84 ( I have always done this)

It looks like my programmer isn't set correctly (as you rightly said)
Looks like we've found it... (I do hope this is it)

My programmer is a K149-BC USB programmer, (don't know if you know of it)

I have fuse settings, I don't really know what they do, and the help doesn't really help.

My fuse edit screen has the following.

WDT this is enabled
MCLRE this is disabled ( could it be this....!!!!)
Code protect ROM this is disabled
Bandgap this is set to highest
PWRTE this is enabled (I know what this does)
BODEN this is enabled
Code Protect EEP this is disabled (I know what this does)
Oscillator INTOSC IOGP4 IOGP5 (I know what this does)

Any ideas on the other ones,
I have programmed 16F84's, 16F627's etc all set as default, and these have been fine.


Thanks again,
Cheers
Dave..

[Melanie]

I can't answer questions on your programmer as I don't have one.

Your CONFIG settings should match those preset into the program, but whether your programmer is actually programming them is another qustion.

If MCLR needs a pull-up, then the CONFIGS sure don't match (or yor PIC is broke)... it could be there's another tick-box in your software for your programmer that needs activating. My software for example has the ability to program the PIC and leave the CONFIGS untouched unless I've set it on another screen. This also means that GPIO4 could have OSC coming out of it instead of it being used for I/O.

Worst case scenario is I can send you my PIC, but it means you can't make changes if your programmer is misbehaving.

[g7jiq]

Hi Melanie,

Some very good news, I managed to get it sorted,
It works superb,

The problem I had was two fold,
The first one was the configs fuse settings, It now works without the 4k7 pullup resister on the MCLR pin. (just as you said)

It would then work in the breadboard fine but not in my circuit,

To cut a long story short,
When I lifted the output pin and dropped an led on it, it worked fine,

So.... I found that,

The pic's output drives an opto and led in series, with a 470 ohm to the 5v rail.
The pic also feeds an input to another pic, (which drives my lcd)
Somehow there wasnt enough current to drive the circuit even tho there should have been,
so I fitted another opto isolator as a buffer and this sorted it.

What a run around,

Many many thanks for all your help and patience, your a star...

Cheers
Dave...

[Archangel]

2 rules in this forum:
#1. Never doubt Melanie.
#2. Go back to Rule #1

[g7jiq]

I never doubted her in the first place,
I just couldn't see the wood for the trees....