oksidizer USB2DMX

[yofo]

interesting, to my knowledge, using caps will corrupt the data

They corrupt signals (or 'data' if you like) when you use the wrong values connected the wrong way.
So if you don't use a 47 pF cap or you connect it the wrong way, yes, then the DMX signal which consists of really high frequencies (~250 kHz) wil be destroyed big time.
Connect the 47 pF good and the DMX signal is about the only signal that gets passed... Other shit (like a power spike or DC) is blocked mostly, preventing the interface to go down.

and USB is sensitive, I have had troubles with my USB devices for ever, it first started then I used usb webcams for cctv, it keep on freezing up then I turn on anything that works with a motor, or induction setup, lol, but that was replaced a couple of weeks later with the real deal, and a capture card, but this is just for interest sake, how sensitive usb is

Reading this I hope you have thought of immediately testing your DMX interface + rig on another computer?
If not; do so!
Its not normal for any USB interface to go down every time an electric device does something bad, that makes me think the USB interface (or build in filtering (thats with caps also)) is faulty.

connected the wrong way.

then your saying connecting it the wrong way, do you mean by wrong polarity or onto on the pins "parallel"
or in series > wire from Pin---||----soldiered onto Pin


I have used my dmx adapter onto my laptop last year December end year, and it had the same problems with the laser freezing the dmx adapter...


This wants me to stuck a 47pF cap onto every data---||----ground pinout on my dmx adapter, dmx out and usb, I think I still have some caps left over from a previous project from years ago...

[IanS]

Not sure if I can help any further, my interface is completely stable since I sorted out the USB power-save issue.
BUT - the interface I built is not the standard design, I included opto-isolators on the outputs (it has two outputs, so acts as a DMX splitter as well). So the idea of interference getting through the power lines could be a factor. I also added some mild filtration to the USB input, 27 ohm resistors in series with each line, with 33p capacitors to ground from each one. This will only have any effect at high (radio) frequencies, so a ferrite core wrapped round the USB cabnle would probably work jut as well. For what it's worth, my AC input has a power filter built into rthe connector to prevent noise spikes getting in that way. Not that I'm paranoid about interference or anything...!

Ian Sheldon

[yofo]

Not sure if I can help any further, my interface is completely stable since I sorted out the USB power-save issue.
BUT - the interface I built is not the standard design, I included opto-isolators on the outputs (it has two outputs, so acts as a DMX splitter as well). So the idea of interference getting through the power lines could be a factor. I also added some mild filtration to the USB input, 27 ohm resistors in series with each line, with 33p capacitors to ground from each one. This will only have any effect at high (radio) frequencies, so a ferrite core wrapped round the USB cabnle would probably work jut as well. For what it's worth, my AC input has a power filter built into rthe connector to prevent noise spikes getting in that way. Not that I'm paranoid about interference or anything...!

Ian Sheldon

hehe, nice..., do you maybe have soms pics and/or circuit diagrams of the opto-isolator and your modification your have done to your DMX adapter, I think this might fix my problem....

[dmxlighting]

I think this might fix my problem....

Well if not I have a big hammer you try

[yofo]

I think this might fix my problem....

Well if not I have a big hammer you try

lol, I kinda feel like that already, I hate to struggle with this crap , lol, but the other side is, I'm learning a lot about DMX related problems..So hopefully I can build my knowledge for in case on emergency, I was at this one club a 5 weeks ago, And ask the DJ to put on the 4 head laser
they're like using with small 8 or 12 or 16, "cant remember exactly" slider controller for their lights, lol, but the DJ told me, they're working on it, and then later on I see someone struggling with all the DMX lights, and start unplugging all the dmx cables from the scanners and unplugging the power and plug it back, and so on, so something was seriously messedup, so the entire night I was dancing and looking up at the lights, so that probably looked weird, lol

[yofo]

Ok, my laser is pumping out a massive voltage spike arose dmx line, then it gets turned off and on, the turning on part have biggest spike, I placed a LED onto pin1 and pin3, from the laser dmx cable, and I did the same later with my dmx smoke machine, and the led very very dim then I placed the led in, and it doesn't spike then the turn the smoke machine on and off, so.....hmmmm

So someone is probably screaming at their PC screen, "get a mofo opto-Isolator" or something.......lol
but buying one cost to much for me, I'm only a amateur LJ

[dmxlighting]

I'm only a amateur LJ

Most peolpe on this forum are amatuer or started off this way.
Its very easy for me and others here who have some money to buy the right kit and advise that you do the same.
Thing is that WE have learnt that sometime the only real way to do these things is to buy the right thing in the first place.
That might mean saving the pennies rather than rushing into making a purchase.
With that said I do understand your frustration with what you have and the restrictions you have.
I can't help but think that you are doing something really really wrong somewhere that is causing you to have all the problems you have listed over all the many posts you have made.

The first thing I think you have got to do and I belive I have said it before is get yourself a good quality, factory made usb / dmx device.
The oksidzer thing you have is the likely cause of some if not all of your trouble. Cut your loses and get rid of it. The more you battle on with it the more problems you will have.
Also I get the feeling from reading your posts that you are no elecronics expert and as such should really not play around with your kit in the way I think you are. To get massive voltage spikes on your dmx chain is a huge problem and you WILL kill any fixtures on the curcuit in a very short time. Stop now before you fuck up what you have.
Get back to basics and except that you have some problems that trial and error is not going to resolve. Look around for someone near where you live that could help you.

I do understand the problems that a new person will have when trying to learn all about a new hobby.
My lastest hobby is my marine fish tank. I started it in December when I knew nothing at all.
Now its the end of March (4 months later) and I have learnt loads form books, internet and other marine fish keepers.
I did a massive amount of research BEFORE I plugged in the pumps, lights, heaters and filters.
Ive never lost a fish and my tank runs perfectly. I was told that new people WILL lose their first fish within a few weeks of introducing them.
My tank water has been tested by experts and the chemisty is so good that they don't belive me when I tell them that im only a begginer.
I belive the reason I have not had any problems is that I learnt all I could and did everything properly from the start.
(I should mention that keeping marine fish is considered to be very hard work to get right).

My point is that there are no short cuts to getting this done right and working properly.The same applies to you and you need to research more.

Above all thing though, BUY A BETTER INTERFACE!!!!!!!

[yofo]

man thx for your tip and I have the idea you understand me wrong on the part where I said the laser is going of a spike. and by getting a new interface will fix all my problems, but I'm going to fix this one, I know alot of electronic, and have built a lot of stuff in my life, I just have a translation problem, because I'm not a eng man, I'm a white boy from South Africa hehe....soccer 2010, blablabla
I'm very careful with my stuff...

Laser--DMX plug - LED on pin 3 and pin 1, it's totally disconnected from the chain, laser only, and this is how I test my stuff now, and my laser is giving of a larger voltage then the dmx adapter is giving out, wierd... my other dmx device is not giving of any spike..

[yofo]

problem is gone, unit doesn't freeze anymore then I turn on the laser or off it keeps on going with it's mission, and it works, is it cool to run dmx without a pin1 connected? because I've done just that, because I've pin pointed all my problem is with a ground (pin1)

[yofo]

noooo...... LOL.... I've build myself a opto-islolator last year, the freezes is gone, only if I bump into the USB cable, or something like that, then it freezes. :*(