What am I doing wrong ?

[Acetronics2]

Hi, Malc

Don't you think a simple triangle slow wave generator based upon a 555 or a twin AOP could perfectly do the job ???

Note a simple bulb lamp could also do all the job itsef ... with a rectangular wave input.

mmmmh, back to the original idea ... you'll have to seriously slow down the PWM change rate ...

May be intended for some stop light for road/rail crossing, I presume ???

Alain

PS : and why not use a lookup table, just to reproduce exactly the truth ( exponential rise and fall of enlightment ) ???
just a " particular shape " wave generator ...in fact.

[malc-c]

Hi, Malc

Don't you think a simple triangle slow wave generator based upon a 555 or a twin AOP could perfectly do the job ???

Note a simple bulb lamp could also do all the job itsef ... with a rectangular wave input.

Quite possibly, however that wouldn't improve my understanding of PBP

May be intended for some stop light for road/rail crossing, I presume ???

Errr.. actually you don't want to know... Oh well all right..

A friend wants to model the Tardis from the BBC series Dr Who... and it has a slow pulsing light on top..... me and my big mouth offered to help, and like I said it works fine on a 16F628a, but I just need to port it to a 12F675

Malc

[Acetronics2]

Hi, Malc

That's a bit more complicated ... as Dr Who is completely unknown here !!!

May be some more info about that light timing and appearance ( flash, slow rise and fall, Pulsing light ....) could help us to help you ...

Alain

[malc-c]

Hi, Malc

May be some more info about that light timing and appearance ( flash, slow rise and fall, Pulsing light ....) could help us to help you ...

Alain

I was going to attach a short avi (DVIX codec) of the result I have with the 16F628a chip, which is exactly what my friend wants..., but even zipped its slightly more than the max 200K limit we're allowed to upload. If I can't get the 12F675 working I'll just mail him the '628 chip and save all the headache !