Don't blow your fingers off with this PIC idea

[bartman]

"...it's still a public forum, anything posted in here could be done with or without your agreement by xyz person..."

It was a joke. Except if you built it Steve, then I want my money!! :-)

I used to launch the rockets using a 6v lantern battery. I guess it wouldn't take much to figure out what is needed. The little relays would be a good idea.

As for timing. I was thinking more along the line of pushing PLAY on the stereo at the same time as pushing "START" on the firing system and doing all the timing strictly on the PIC. So, each "Show" would be its own program. Your idea may be easier to "program" though using some sound editing software and offsetting the right channel for the launch signals to allow for timing of the launch to the explosion.

What about safety measures when hooking up the igniters to the fuses and starting the PIC hardware? I've been thinking of a separate physical switch that would apply the igniter voltage to the system once the software was running and stable.

Bart

[mister_e]

Except if you built it Steve, then I want my money!! :-)

LMAO! you know what else i could build... and no way i will

Back to the topic, It could be something like... when you press 'play', the right channel send another tone to apply power on the relay contacts. on your device you may add a 'Fire fire fire' panic button to shut down the power...

But it could be useless too assuming you'll use the N.O. contact of the relay... You may decide to monitor the target igniter line in case there's a short on one line... a fuse in serie will be enough and more simple for you.

Safer is better.. sometimes.

Hook your igniter, then apply power on your device. In case of a defect relay... it could save your... kinda beauty ROFL!

[bartman]

Okay, this really has me thinking now.

I looked at the dinky sound editing program I have and it can generate any tone of any length. It also can generate touch tones (which might be helpful too).

If I'm understanding you correctly, it wouldn't really matter what the tone was as long as the program was designed to recognize a specific tone on the right channel and ignore any other possible noise. The program would just open the valve to supply power to each igniter with each tone it encounters on the track. Just a simple counter - lite 1, lite 2, etc.. The software itself would be only a few lines of code with the most complicated part (for me) recognizing the tone.

I'd want some other feedback, but would need to do it without using any other outputs. Perhaps a RED led when it is firing turning to GREEN when complete. Either a single one or maybe a row, one for each igniter. A tricoloured led on the output... I need to think on that. Maybe a multiplexer to have more "channels"?

So, in practical terms a music selection of suitable length is loaded into the sound editor, strip away the right track. Study the music and add tones on the right side corresponding to the musical peaks then offset the right track with whatever delay is required to account for fuse burn and timing for the firework bursts.

Burn the CD and put in a discman or laptop. Modify the headphone plug so the left goes into an external amp and speaker set up and the right to the PIC control box.

Start up PIC box then arm igniter power.

Push play on the discman and watch the fun.

I just need to play with the igiters and fuses to see if they will ignite. I can't see any reason they wouldn't.

Bart

P.S. I'd have to totally wrap my head around different safety methods before building that portion. Mentioning shorts is a perfect example as I didn't consider that type of malfunction. I'd need something simple, but reliable. I think that a tone that would trigger the main power to turn on is a good measure. I'd still want to add a physical switch to apply power, but not have the final switch until I'm out of the way.

Another thing is the line from the discman to the control box. I'd say it would need to be 50 feet at least. 100 even better. What kind of signal would you get out the end of a 100 foot line from the earphone plug of a discman? Enough to even see it at the PIC?