hippo joy

hippo joy from nikkipugh on Vimeo.

I’m liking this circuit-bending stuff. It’s making me do things I don’t want to do.

The particular comfort zone edges I’ve noticed are:

• Restraining myself from immediately unscrewing the back and tinkering with the innards without having properly explored what the ‘normal’ behaviour is first. I must make more of an effort to document this too.
• Choosing the 3 or 4 bends from several that I’ll try and work with. This is usually a balance between the “awesome!” and the practicality of getting wires and soldering irons where they need to get to. I ‘lost’ a really nice bend in the hippo – the behaviour changed when I soldered the switch wires onto the board. I’m starting to get into the habit of making audio recordings of the initial noodling noises. [audio:http://npugh.co.uk/media/hippo.mp3]
• Revising the previous decisions, based on what switches you can accommodate in the shell.
• Making the first incision. Usually my electric drill is hilariously large compared to the toy I’m working on: one of these days the toy’s just going to disintegrate. It’s also a very definite point of no return.
• I’m slowly getting better at drilling holes a few sizes too slow and then taking them up to size with a file. Neater results, but there’s still room for a lot more improvement. I’ve also started thinking a bit more about the feel of the switches – adding in rubber o-rings to cushion body contact points etc.
• Similarly for the first solder, but given extra edge by the memory of all the circuit boards I’ve managed to kill in the past.
• I’ve circuit-bent a few toys now, all with similar push-to-make switches and body contacts. An important edge is coming up where I’ll have to learn new stuff. With the hippo bend I made myself repurpose the existing switches. It’s a bit of a bodge, but it was worth the brain-wracking to come up with a (hopefully more than temporary) solution that a) works and b) is satisfying in the way that it looks and touches.

A Flickr set of images showing the hippo’s internal gubbins is at http://www.flickr.com/photos/nikki_pugh/sets/72157622183430094/detail/

First steps in circuit-bending

I’ve been trying my hand at hacking some kids’ toys ahead of the “noobs attempt circuit bending” event I’m holding at my place next weekend.

A quick trawl of the charity shops in King’s Heath gave me 3 things to work on: a cow, a stereo and a keyboardy thing. 2 days in and I’ve already killed the cow and the stereo.

The cow was the first to go due to careless random shorting of points on the circuit-board upstream of (or possibly across) resistors. Even without a voice though, the cow is all sorts of awesome, so I’m sure it will house some sort of project in the near future.

2nd-up was a little orange boombox with the usual assortment of play and fast-forward buttons, but also a neat little contrivance where putting different plastic ‘CDs’ in the tray would push different combinations of switches and change the playlist of songs. (Is it wrong to get excited about a switch?!)

Noodling around on the circuit-board was quite disappointing until I tried the lick’n’press method. Behold! Wibbling a damp finger over R1 gives a nice Theremin style distortion of your nursery rhymes! That’ll do.

[audio:http://npugh.co.uk/media/bitbent.mp3]

I soldered a couple of wires to each end of the resistor and then connected the other ends of these to some split pins mounted on the top of the plastic casing.

I could now control the degree of distortion by varying how far apart the contacts with my body were (the body acts as a resistor: one thumb bridging the contacts < two fingers on same hand bridging the contacts < a finger from each hand bridging the contacts). Using a wet thumb would not provide enough resistance and the chip would short out and stop playing music - so I added a push-to-break reset switch between the batteries and the circuit board so I didn't have to keep taking the batteries out each time I needed to restart.

I also added 3 slide switches so I could change the track selection without having to change CDs.

After reassembling the stereo and finally figuring out where the left-over piece went, I spent a long time exploring different combinations and effects. ***bliss!*** [and coming from someone who considers themself to have negligible musical ability, that’s some pretty powerful bleeping to hold my attention for long enough that it was probably starting to really annoy the neighbours!]

So anyway, all was good until I noticed the demo button wasn’t working because one of the wires I’d added was running between it and the circuit board. In moving the wire I managed to detach it from the board and then in trying to reattach it I managed to ping the resistor off the board too.

R1 is a tiny-beyond-description surface mount jobby located right next to the black dot where all the magic happens. Needless to say I managed to bork everything in trying to make the simple repair. Cue much frustration and swearing!

Oh well, I’ve learned a lot in the process, made some sweet, sweet, music …and also become hopelessly addicted to circuit-bending. Guess I’m off to the car boot sale tomorrow morning to pick up some more things to break!