The delayStick

After going thru’ tutorials, I realised that I wasn’t really that interested with synthesis sound as created with sine and sawtooth waves but more interested in manipulating existing sound. As in a previous post, I remember seeing a guy visiting iDAT who had this bag of gas that you squeezed to produce sound and he wanted to do the same but use live street sounds which I thought was pretty cool. In the patch I used delays primarily because that was the effect that I understood fairly quickly. The patch might not look particularly sophisticated but by waving and twisting the stick, you get some interesting effects.

The delayStick has 5 tilt switches at one end of a tube arranged at different angles to form an array. Because the tilt switches activate at an angle of 10 degress from rest, by having them like that allows them to activate at different times when the tube is moved around. The tilt switches are connected to a circuit board from an old PS/2 keyboard and generate a keypress when tilted. The ascii value of the keypress is then used to calculate the amount of delay to put onto the audio feed.

Download Max/MSP patch file

Download source text file

Watch Quicktime movie of delayStick in action (3MB)

Constructing the stick 2

So after after a bit of a rest to recharge the batteries (that’s the soldering iron, not me!), I connected up the last tilt switch to the keyboard matrix, did a quick test with my patch and I was ready to get it into the pipe. I dropped some string thru the hole and down the pipe, tied it round the end of the PS/2 connector and pulled it up. Unfortunately, the cable wouldn’t bend enough for me to pull it thru the hole and the pipe was too narrow for me to get my hand up to try and force it to bend. I had a cardboard tube which at the time I thought was too short, so I retrieved it from the “stuff to go to the recycle” pile and slapped some paint on. Whilst it was drying, I sprayed the matrix and my soldering with a thin layer of plastic sealant to try and protect it when it would be pulled thru the tube.

After a couple of hours, the paint was dry. I cut 4 slits in one end to hold the card which the array of tilt switches were stuck to and a small chunk at the other for the cable to feed out of. Then I started to feed the cable, followed by the matrix which was then followed by the array into the tube. A couple wires snapped which needed a quick repair with solder and insulating tape but other than that no major casualties. I trimmed the card, put some tape round to help to hold them in place and popped the covers on the ends of the tube. After a quick test it looks as though the delayStick is ready to rock.

Constructing the stick 1

Finally got my soldering iron out and started connecting tilt switches up to the keyboard matrix. Everytime I connected one up, I quickly tested it with my patch and each one generated the values that I expected which was a bit of a relief. As with putting the Simontron together, my soldering iron needed recharging right at the crucial moment which in this case was putting the last tilt switch circuit together. Still, at least it let me start work on the pipe.

Thanks to the combined efforts of Mr Black and Mr Decker, I managed to drill a hole in the pipe for the cable to feed thru without splitting it. I then cellotaped the tilt switches to some paper to workout the best positions for them. Not a roaring success but then paper isn’t the most inflexible material around. It did give some readings but 2 seemed to dominate the proceedings so a rethink on the order is likely to be needed. It has highlighted a problem that I had first thought about when I came up with concept but had shoved to the back of my mind – how do I fix the array inside the pipe? I’m thinking something along the lines of a couple of small holes, cocktail sticks and some superglue but that’ll have to wait ’til tomorrow. In case you were wondering, the post-its are so I know which switch generates what signal.

That was close

Had a bit of a scarey moment today with getting live audio into a mac. I took my Griffin in, rigged it up with my iPod and knocked up a simple patch just to make sure that it all works. Once I eventually managed to get a mac to “play” via a mixer, I then tried to get the iPod/Griffin combo to work. Nothing. Swapped usbs, played about with settings but still no joy. Got Benji involved and after a good half hour he was no further ahead than me. He said that some people had the same problem last year and overcame it by plugging straight into the input socket on the back of the G5. That’s fine by me, don’t really care just as long as I can get live audio into the mac somehow.

On the subject of live audio, the road outside of Babbage is pretty quiet so I’m wondering if I’ll get any good street sounds when I come to demo it. I might just ask for someone to volunteer to plug their iPod in. I could ask for them to speak into the mic but I don’t think I’ll get many takers 🙂

My patch is pretty much done. Following on from deconstructing other patches and a couple tutorials that came with Max, I’ve gone with the delay and testing with a normal keyboard produced some pretty good effects. Even managed to extend a Killers track by 3 minutes – no most Killers tracks are not 3 minutes longer than they should be either! So anyway, pretty much on course although I’ve still to cut and drill my pipe and solder up my switches.