Updating HPWM frequently, safe?

[mister_e]

Can't tell ya! But as far i remind, the datasheet suggest a maximum impedance of 2.xxx Kohm.

I tested my code on a EASYPIC 4 board with 10K trim pot... seems to work.

Post your schematic but make sure your PSU is well filtered and is strong enough for your need first.

Weird, weird, weird.

[Darrel Taylor]

Oh Great!

Thanks for trying it Steve.
It helps to know not all is lost.

I think I've got a 683 around here somewhere.

Maybe there's something I missed for the little guys.
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[peu]

Im using this schematic:



Im using a recently charged Li-Ion (3.635v measured under load using a good multimeter) all is mounted in a protoboard

Using my last posted code the LED flickers, if I press the button it goes steady

Thanks!

[mister_e]

mmm, yeah it works.. but a scope attach to show few glitches... mine too.

Deeper analysis show that flicker go away if i don't turn off the PWM off before updating the duty cycle. So maybe i have those latest silicon version.. and why the datasheet no longer suggest to turn off the PWM module...

aarrrggghh

[peu]

let me join your ARGHHH...

Thanks Steve, at least now I know Im not alone here

I ordered some 12f683 samples not so long ago, if they changed something I guess I could test it with a rather new IC. But they are at my office, will check tomorrow if time allows.

Thanks for the continued help guys!

Pablo

[mister_e]

in my code just remove the following line

CCP1CON = PWM_OFF

and also that one

CCP1CON = CCP1CON | PWM_ON

In darrel's include, comment out line 160

MOVE?CB  0, CCP1CON

At least, it work here.. thanks to my scope

Now the history don't tell if this will work with ALL PIC #, and with ALL silicone release. Time will tell.

[T.Jackson]

You are a genius Mister_e. Wish I was as smart.

[mister_e]

Don't give up, maybe one day you'll be. Then i could hire you

[peu]

I removed that line from Darrel code and its clearly more stable now, but it still flickers at the lower range of the pot... very strange...

I just modified the code I posted to write to eeprom the lowest pot setting where its stable, the read value was from $007B to $007C but I recorded a couple of $007F and $0068 after 125 readings/writes, my guess for these oscillations was someting in the write cycle because after I stopped reading the led went to steady again, I wish I had a scope...

modified code:

if calibrapin=1 then
if conta < 250 then
 write conta, pote.byte1
 write conta+1, pote.byte0
 conta=conta+2
endif
endif

Pablo

[Darrel Taylor]

Strange indeed.

Well, I've made the changes Steve found and posted it at the same link.

I won't get my scope back till wednesday. (should have waited)
But I'll sure have a good look at it then.
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