a strange question

[Dan Brown]

i know this is going to sound a bit daft but it is a serious question i'm afraid

can any of you think of a way of converting audio to g.code?

i was thinking about the LEDs you get on some sterios showing the volume of differant chanels from green up to red

now if i could find a way of translating that to stepper motors turning from 0 to around 190 degrees i could make a friend of mine very happy and i could even get a job out of it:naughty:

any thoughts would be apreciated

Dan

[Dan Brown]

i don't suppose you could elaborate on how i would rig that up could you? i'm realy dumb with electrics (the devils business if you ask me)

[irving2008]

What exactly is your need? If I read you right, what you are asking is what virtually every car dashboard does today... the speedo and rev counters are stepper motors driving the nedle... It not hard to achieve...


If you dont mind I shall move this thread to the problems area...

[Dan Brown]

Thanks for moving this post Iving,

I knew this was a silly question and its probly not even appropriate for this forum but as i'm in the early stages of getting all the stuff to build my own cnc machine i've got stepper motors on my mind, so when my friend who is organising a festival in portugal approched me about rigging up some sort of fire display the first thing that came to mind was gas torches controlled by stepper motors

i'm sure i could use mach3 to run some motors for some random affects but if i could get the steppers to move in time to the music i would be 'the man'

[FatFreddie]

i'm sure i could use mach3 to run some motors for some random affects but if i could get the steppers to move in time to the music i would be 'the man'

Hi Dan,

I'm going to start off my conversion by running the steppers from an Arduino Duemilanove board which is a small processor with lots of IO and is easy to program. It has analog inputs which you could use to sample the sound and should directly drive a stepper controller from it's digital outputs.

They're programmed in C using a PC to compile and download the program which is then self sufficient. Big advantage is cost - £25 + whatever the analog circuits cost (probably not much more than a fiver) and simplicity (it's programmed via a USB cable which can also act as a serial link for basic debugging).

You will need to be able to program in C (or C++) though or find a tame programmer but there is a good support forum for it.

I should know more in a couple of weeks - I'm expecting a 3 axis System4 setup to arrive just in time for Christmas :-)

Mark

[Dan Brown]

thanks Mark, that dos sound interesting although i've now idea about programming,

i really wish i could get my head around all this a bit better

[irving2008]

Stepper motor controlled gas valves... hmm nice idea, and not hard to rig up... but i wouldnt use a stepper.. adds complexity... i would use a RC servo and generate a pulse width based on the average signal level at each frequency I want to sample. The only issue might be the reactiveness of the valves..would they be able to move fast enough?

What sort of fire display?

[Dan Brown]

the valves shouldnt be a problem in regards to how stiff they are as i can have a second manual valve to shut of the system completly therefore the stepper/servo driven valve can be loosend as it dosen't need to be totally gas-tight as there will also be a constant pilot light that besides makeing sure everything ignights properly will also burn of any lost gas.

the only problem with useing servos instead of steppers is that since i realised it was possable for someone like me to build a cnc machine the learning curve has been fairly steep and this follows for ALL my current ways of making a living and i'm starting to get the feeling that maybe i was issued with a pretty small internal H.D

it seems for everything i learn i have to forget something else

so servos may be economical in one way but in brain space they are proberly more than i can afford

[Dan Brown]

answering your question irving the display i have in mind is maybe six indapendant 10 foot (above the stage platform)poles (well away from the crowd obviously) on oposite sides of the stage area giving off varying size puffs of flame (the max being roughly no more than 1 foot in diamiter) in line with the treble, mid and base,
this would preferably be run from a standard analogue light control unit but if another option is more viable then so be it.

as for the type of valve i am thinking of useing something like a simple quarter turn water stopcock, hob taps are o.k but not enough flow unless i try and modefy in some way

[irving2008]

the problem with an analogue light control unit is that its output is triac controlled AC, they are merely on/off switches. I suppose the gas control valve as used on a boiler could be utilised as that is solenoid driven, but i doubt they'd last very long.

I stil think a radio-control model servo would be a good bet for driving the stopcock and simpler to implement than a stepper motor control...

i think your first experiment is to obtain a suitable valve and find out just how much torque is required to operate it... then we could work out necessary accelerations etc and see what is the best driving technology. The rest, getting analogue signal, frequency splitting it, and converting to a control signal is a seperate issue and maybe an existing analogue light contol could be adapted.

(btw I designed and built an analogue light control chaser for a mobile disco I used to run in the 70's.. it was quite sophisticated for the time, with an 8-channel frequency analyser, each channel controlling either intensity or strobe rate, and a seperate beat follower channel.)