233 replies to this topic

[BrightStar]

Why do you need a device to talk back?
Maybe the igniter test?

Yup, the bus master device (the control laptop in my case) will poll each of the firing modules sequentially for match continuity info when not sending fire commands. The protocol is quite similar to the old GPIB industrial bus - you poll the modules one by one for info and then give them a certain time to respond. This prevents chatter or contention on the shared serial bus - the modules only talk when requested.

As you know, DMX must never be used for pyro as there is no error correction. MIDI show control is much better in this respect and the UKPS RS485 protocol we will invent here will be even better

I'll be publishing all details of the software / firmware / hardware on this forum as it develops as a small contribution to the UKPS (if they will allow me). It would be great if everyone from the society could contribute ideas and features. At this point, I'm looking at Java as the host software and GUI for cross-platform compatibility. This is not my strongest language at present though, so we'll have to see...

Edited by BrightStar, 16 November 2006 - 02:54 PM.

[leosedf]

If you need any hardware design and pcb's etc contact me, i can help.

[hoarp001]

Or me :-)

I have a full blown copper etcing system for making PCBs in my garage. I can do you boards if you give me the artwork...

[scoobie]

At this point, I'm looking at Java as the host software and GUI for cross-platform compatibility. This is not my strongest language at present though, so we'll have to see...

You sure you want to use Java for something that is 'mission critical'? Do you not think Java is a bit unstable for this kind of thing, the JVM is too resource hungry and all together a bit pants? If it was me... I wouldnt use it.. I'm not a developer (but have some development experience from my university days) and personally if I was writing a control system, something more stable would be my preference... C/C++ maybe? Or if you want serious stability, how about ADA

The last thing you want is your control software crapping out in the middle of a display where you have to reboot your laptop

Just my 2p worth... take it or leave it... but it certainly sounds like a very interesting project!

Good luck with it

Scoob.

Edited by scoobie, 16 November 2006 - 08:41 AM.

[leosedf]

scoobie is right.
Even visual basic is better than java for this.

[scoobie]

scoobie is right.
Even visual basic is better than java for this.

Steady on there, I wouldnt quite go that far

[leosedf]

hehehhehehe
But you got the idea!

Edited by leosedf, 16 November 2006 - 03:35 PM.

[Ritual33]

Would be nice for us to design a nice firing system pcb that we could reproduce easily. I wish I had an etching system, they cost way too much

Drew

[leosedf]

You can do many things at home cheaply and produce quality pcb's.

[hoarp001]

You can expose the board on a window sill and developt hem in a jar and etch them in a tray, but the best way to do it is with proper equipment. A proper exposure unit and a heated buble tank will get the best results...

[leosedf]

You can also use Press n Peel sheets which are dead easy to do. The only thing then will be to etch the board.

[Andy on Wight]

This may be slightly off topic but I believe it is relevant to the subject on hand.

I have got a firing box that I am developing for a group of friends that are doing displays. Now whilst the design works I am seeing something that I do not quite understand and I hope that you may point out something that I am missing.

The design is for a 48cues running of 8 channels of 6. Please excuse the desciption for the moment put I will get a drawing done as soon as I can, but by starting at the power supply in a power switch allows power to the box but not to any of the circuit a seperate circuit arm switch does this. Once the arm switch is active there is power, but current limited to 50mA, to the continuity test for each cue, each cue has test LED that lights up if the circuit is active This is then connected to a a pair of speaker connectors with a 1N5401 diode in line, then the fuse to the return connection.

Once the fire circuit keyswitch is turned, power to the push to make switch with its LED is limited to a max current of 3A. The LED is lit when there is a continuous circuit. When the button has been press and the fuse fired the LED will go out.

Now the problem I am seeing is that the button LED does not always go out once the fuse has 'fired'. Any ideas on what may be wrong would be appreciaited.

Edited by Andy on Wight, 18 November 2006 - 09:51 AM.

[karlfoxman]

What e-matches are you using, it could be the pyro mixture has fired but the bridge still is intact.

[ProfHawking]

this is quite common, the ematches i use often short once fired. As long as your system doesnt loose power down the fired line, then you should be ok.
The only pain is that is hard to see whats been fired and what hasnt!

[Andy on Wight]

Thanks for the quick responses, with regards the ematches hmmm no idea they have been got by my friends from the supplier they use.

They have orange twincore wires attached with red covered ignitors with w green plastic sleeve that goes over them. About 3-4m in length with the ends prepared for stripping, I am afraid thats all I know.

Looks like I might have to do a little redesign so that the LEDs are driven by a transistor circuit maybe, out with the old electronics handbooks by the looks of it, been a while since I needed them.

Thanks again.