On Oct 30, 3:38 pm, dodger <
davidmcgo...@gmail.com> wrote:
> ...
> The lights stopped responding correctly. Shame as this was an exciting
> event and we had hired out a bunch of equipment for it.
That's a real shame. I hope we can get everything sorted so your
installation has another chance.
Could you describe 'stopped responding correctly'? Were all the lights
dead? Did some work? Did they flicker and flash? Maybe a silly
question - but do you know the dimmer packs actually work?
> ...
> My fear is it is a timing issue in the code???
That is very unlikely. The code is has been tested on multiple DMX
lamps, a logic analyser and a CPU simulator, and checked against the
DMX512-A specification. A lot of work has gone into testing that part
- as that was the central flaw with the old Arduino DMX solutions. The
timing critical part of DmxSimple is written in hand-coded assembly
language to guarantee timing accuracy.
Are you using any libraries outside the built-in Arduino ones? Are you
using any interrupts in your own code?
> Is it possible that the refresh rate for the frames is to fast on an
> Arduino???
Unlikely, but possible. The specified minimum frame time is 1.204ms,
but the internet seems to suggest not all DMX devices can work that
fast. Try setting DmxSimple.maxChannel(100); to slow things down.
> I do not know that much about DMX and I don’t want to mess about with
> the DMXsimple library.
Here are some things to check.
1) Are you sending enough channels? Some dimmer packs need all the
channels transmitting, even if you're only using the first one. So
make sure you are sending all 6 channels to the Zero88 Betapack 3, for
example.
2) Does a trivial example work? Modify FadeUp from the examples and
see if you can get a lamp working. If so, maybe part of your code or a
library you are using breaks DmxSimple.
3) I know you said you checked your wiring, but have you checked it
works, or checked the connections manually? Beware - DMX often seems
to function even with faulty wiring, and only fails when you start
using different equipment or longer cables. Swapping earth and one of
the data lines is one common problem.
4) Have you used a decoupling capacitor on your DIY shield? A
capacitor (of about 100nF) between the power pins of the driver chip.
You might need one.
I hope that helps. Please report back what works and what doesn't.
Then I can use the feedback to improve the library and/or
documentation to banish this problem in the future.
Peter