How to delay until a next increment of time occurs ?

[R.Wieser]

Dietmar,

> I would assume that this is not an application that needs to output a 100% 
> correct pulse train every time.

Correct.   Thats in the design of the pulses themselves  (25% duticycle for 
one state, 75% for the other. Lots of leeway, and self synchronising)

> You may just repeat the pattern ten times to be safe enough.

:-) I was already doing exactly that.

> Combine it with a light sensor for feedback ;-)

Well ... I see a few problems with that.  Some when I would keep the light 
sensor next to the Pi, and others when I place it next to the lamp. :-p

> Btw. you may want to increase the priority of your task.
...
> os.system( "sudo renice -15 -p %d"%os.getpid() )

Thanks.  That should help the reduce the jitter.

> Anyway, Micropython on a microcontroller would probably be the best 
> solution.

My language of choice would probably be Assembly, but yes.  An (atmel) 
attiny16 (8 pin, 5 free to use) should be enough for it.

But .... first experiment the heck outof the Pi to see how well it can do on 
its own. :-)

Regards,
Rudy Wieser