Circuit-bending workshop at the British Science Festival

On Sunday the 19th of September I’m running three 1-hour circuit-bending workshops as part of the It’s a Geek’s World event, 10-4 at Aston University’s Students’ Guild Hall. (geeks_world on Twitter.)

Toy mp3 player, soon to be more with light and sound than the manufacturer anticipated...

Toy mp3 player, soon to be more with light and sound than the manufacturer anticipated!

We’ll be converting one of these toy mp3 players so that the sound it makes is controlled and distorted by light.

Circuit bend for It’s a Geek’s World. from nikkipugh on Vimeo.

The mod is pretty simple – so don’t worry if you’ve never soldered before – and as you can see from the video above the results are very engrossing. The kits come with earphones, so you can even play with them for as long as you like without risking familial discord! Alternatively… there’ll be another workshop where you can make your own audio amp. Yeah!

We'll switch over a couple of components to make the toy sensitive to light.

We'll switch over a couple of components to make the toy sensitive to light.

The workshop costs £3.50 and at the end of it you’ll have your very own bleepy chirpy tinkly thing to keep.
To reserve your place in advance you need to register on the It’s a Geek’s World website and then you can sign up for the different activities. There will also be a few places available to snap up on the day. My workshop runs at 10:15, 12:15 and 3:15.

The website is mostly booking system and doesn’t really show much of what will be going on, but take it from me: if you like gadgets, robots, and/or electronic noise then this is the place to be.

There are several workshops on offer throughout the day, ranging from learning to solder through to making a Beat Box sequencer with Mr Underwood. Something for everyone!

Nottinghack will be there with Drawdio kits. We had a fab evening when they came to fizzPOP for a Drawdio workshop, so that’s also tried, tested and approved!

We’re not neglecting the blinky light side of things either – there will be workshops for making these colour-changing boxes and a few other LED treats too.

Colour-changing light box

Colour-changing light box

As well as the workshops there will be people from Curious Minds (they of the Star Wars Force Trainer), oomlout, RobotBits and others. Expect interesting things to see, touch and interact with.

Others from fizzPOP will of course be there too, so come along and say hi – we’ll say hi back if we can hear you over all the bleeping noises!

Circuit-bent furby makes an appearance

Small-child-and-circuit-bent-furby win. from nikkipugh on Vimeo.

See, it’s all about the performance for one.

circuitbent easy button

After Jimmie Rodgers described his use of it for circuit-bending workshops, I thought I’d investigate a simple hack of the Staples easy button.

Prototyping with a breadboard

Prototyping with a breadboard

I swapped out the clock(?) resistor on the circuitboard for a light dependent resistor and here are the results:

circuitbent easy button from nikkipugh on Vimeo.

Except, that’s not all the results!

There’s not a lot to this thing: you vary the amount of light getting to the light dependent resistor and it affects the speed at which the “that was easy” sample is played back. It’s highly addictive though. It’s just the right size and weight to go in your hand and there are so many different effects you can get from it. There’s even a noticeable change in behaviour depending on what time of day you play with it.

Not that I’ve been playing with it instead of getting on with some work, you understand…

Circuit-bending a Funky Furby #7: performance for one

Since I started this circuit-bent Furby project, people have been nudging me to do some sort of a performance with it.

I struggle with this idea, I think for two main reasons.

The first is that I’ve never been to a performance that even remotely indicates to me what a circuit-bent Furby gig might be like. What might a circuit-bent Furby gig be like?

The second is that, as Danny started to get close to with his questioning of how I relate to the Furby as I’m messing with its circuits, the interesting thing about this kind of object for me is how people interact with it.

Furby & Thingamagoop by Katchooo on Flickr

'Furby & Thingamagoop' by Katchooo on Flickr

Fiona asked me to bring the Furby along to her recent birthday party. Brilliant! A chance to see how other people play with it!

It was great to just sit back and watch as different people responded to the thing in different ways. Also good was how people responded when the Furby failed to respond …and the different ways in which frustration, anger and dominance were expressed! This is the stage where I start to find out what it is that I have made. Up until then, it’s just been a learning project as I try and improve my electronics skills. It starts to come alive only once I put it into the hands of other people.

So, the idea of a performance and therefore of an audience is quite an alien one for me. I’m more interested in participants; in audiences of one.

Here’s Pete figuring out Furby-Thingamagoop interaction:

Performance for Furby and Thingamagoop from nikkipugh on Vimeo.

Would you like a circuit-bent Furby?

I’m unlikely to part with this one (still needs a name, by the way), but I’d like to know if people would be interested in commissioning their very own circuit-bent Furby?

well-funky furby

well-funky furby

It looks like Funky Furbies (like the one above, video here) are going on ebay for about £20, so let’s say that after they’ve been circuit-bent and had extra components put in etc etc you’re looking of a starting price of around £50.

furbile from nikkipugh on Vimeo.

It might be possible to get a smaller one, like the above, on ebay for less, maybe even £5, but that depends on how the auctions play out…

Anyway, if you’re interested in commissioning your own unique little ear-wiggling bleepy thing please contact me and we can arrange a design brief and a budget to work to.

Circuit-bending a Funky Furby #6: new ears

Furby Ears from nikkipugh on Vimeo.

I replaced the LEDs from the last round of modifications with 4 white LEDs (in parallel) and a 1k ohm resistor per ear. Much better!

Circuit-bending a Funky Furby #5: switches

Working directly on the circuitboards to find glitches was very difficult, especially since most actions involve, well, action and the Furby kept moving around.

Not a particularly effective solution...

Not a particularly effective solution...

Removing the feet again allows the Furby to stand fairly steadily on the base of the battery compartment without the leg cams reaching the surface it’s on to make the body move. However, this also means you have to down tools and pick the Furby up each time you need to turn him onandoffagain. With all the exposed mechanics and electronics, finding a safe place to pick him up by is a challenge in itself.

On-off switch

The on-off switch doesn’t appear to be directly connected to the battery compartment as in simpler electronic toys I’ve worked with, instead 3 wires come out from the back of the switch and join onto the circuitboard.

snipped wires from on-off switch

snipped wires from on-off switch

I just snipped the yellow, red and green wires about an inch away from the switch (enough to leave me room to solder back onto the wires going into the switch, if needed) and then extended the wires connected to the circuitboard and soldered a SPDT toggle switch onto the other ends.

Extensions to the on-off switch wires

Extensions to the on-off switch wires

Tickle me

I also wanted to add remote switches to the belly, mouth and back of the Furby. All these plug into the circuitboard and, thanks to the coloured wires, are reasonably easy to identify.

Wires from switches; old and new

These are actually connections for LEDs (see later) but the principle is the same for the switches

It’s also pretty straightforward to solder a couple of extra wires onto the leads of the plugs where they come out onto the front of the circuitboard. I’m just using some momentary push-to-make switches to trigger the Furby. It’s nice to have a few actions that are not in response to voice commands.

Audio jack, glitch switch and back trigger

Audio jack, glitch switch and push buttons for belly and back

I also tried to use a push-to-make switch to control the sound glitch, but found I was killing a lot of switches in the process. At first I thought I was over-heating them at the soldering stage and messing up some of the internal contacts, but I eventually noticed (with the help of my multimeter) that it was after a few pushes that the switch stopped working. I thought that the current might be too high for the switches and so added in a 10ohm resistor, but was still getting sketchy results.

Increasing the resistance had the effect of speeding up the sound (not particularly desirable) so rather than increase the resistance I eventually abandoned the push-to-make switches in favour of a chunkier toggle switch (also with 10 ohm resistor).

At one stage I tried a large latching push-to-make switch, but I struggled with this because it was never clear whether it was on or off. If you’re going to go down this route, I suggest maybe using one with an indicator LED…

All-in-all there’s now a significant number of wires coming off the Furby and the solder points are quite delicate – particularly those ones that connect directly to the circuitboard. In order to add some protection against accidental pulls, I tied a piece of nylon cord to some of the plastic structure of the Furby and added a few polymorph figure-of-eights. I then looped each wire through the figure-of-eights before then taking it to the switch box. The nylon is slightly shorter than the length of the wires and tied off inside the switch box so it should hopefully take the brunt of any excess force.

Cord stay to protect wires from being pulled off

Cord stay to protect wires from being pulled off

The switch box: main on-off switch and audio jack, glitch toggle switch and 3 buttons for belly, mouth and back triggers

The switch box: main on-off switch and audio jack, glitch toggle switch and 3 buttons for belly, mouth and back triggers

Flashy lights

I’ve also attached a few LEDs to various points on the circuitboard (again, the solder points on the other side to where plugs attach). These were initially soldered straight onto the board, but have now been added onto wires in series with a 1k ohm resistor.

Initial (temporary) location of LEDs

Initial (temporary) location of LEDs

As I write this, the LEDs have made it to the ends of his ears and mohican spikey thing, but I’m not quite satisfied with the result. More tinkering required – perhaps either to add more LEDs down the length of the ears, or to add some sort of translucent cover.

I need a name from nikkipugh on Vimeo.

Circuit-bending a Funky Furby #4: audio jack

As I mentioned in the last post, I found some sound bends on the Funky Furby I’m circuit-bending.

The next step was to add an audio jack so I could play the Furby’s sound through a mini amp.

This is only the second project I’ve ever added an audio output to, so I’m still kind of fumbling my way through.

To cut a long story short, through a combination of peering at Alfonso‘s innards and section 7 of this circuit bending faq, I arrived at the following:

Wiring of the audio jack, including a 10 ohm resistor between points a and c

Wiring of the audio jack, including a 10 ohm resistor between points a and c

I’m using a 3.5mm enclosed chassis mount jack socket from RS, (part number 106-874), which has quite an open structure, so it’s pretty easy to see which bit is which.

Basically the two bottom connectors are the signals, and the one coming off the side is the ground.

Here’s a diagram of the wiring and how it connects up to the circuitboard and the speaker:

Diagram showing the wiring arrangement I ended up with for the audio jack

Diagram showing the wiring arrangement I ended up with for the audio jack

It’s ever so slightly different from what’s described on the oscillateur faq page, since I’m connecting c to b, rather than c to the ground of the speaker. I did try that, but got no sound.

The other thing I’m finding is that I still get sound from the Furby’s speaker when I plug the amp in. This doesn’t happen when the resistor is omitted, but the sound quality isn’t so nice, so I think I’ll put up with that.

I’m still not really convinced I’m doing this right, but I’ve not yet found any other combination of wiring that works. Maybe I’ve got my positive and negative terminals on the speaker mixed up?

If anyone can point me in the direction of a solution then I’d be most grateful, because this is something that’s going to keep coming up and I’d quite like to learn how to do it properly!

Update!
I had wrongly identified which were the positive and negative terminals on the speaker. After changing that starting point, the audio jack now works as expected with the following wiring:

Correct (I think!) wiring for the audio jack. Without an amp plugged in, the Furby's internal speaker is used. When the amp is plugged in, the internal speaker cuts out.

Correct (I think!) wiring for the audio jack. Without an amp plugged in, the Furby's internal speaker is used. When the amp is plugged in, the internal speaker cuts out.

Circuit-bending a Funky Furby #3: sound chip

Today I found a stable bend point on the Funky Furby I’m trying to circuit-bend!

On a whim I started exploring the small chip behind his left ear and I found this:

Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.

Connecting a few different pins (with a wire, to short circuit them) gives the same effect. I’ve marked them in the photo below…

Pink lines show where to short across the pins to get the effect in the recording. There are 4 different wiring options shown here - just choose one!

Pink lines show where to short across the pins to get the effect in the recording. There are 4 different wiring options shown here - just choose one!

These bends don’t affect movement at all. Though I’m happy to have found these ones – and think they’ll sound great when amplified – it’d be nice to have some movement loops too…

Update: Pete Ashton has set the above sound file to music

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Circuit-bending a Funky Furby #2: looking for bends

I’ve not really got organised properly with this yet, but did stumble across a short-circuit yesterday that locked some of the motor stuff into a loop.

Motor glitch from nikkipugh on Vimeo.

Another furby bend point. Possibly. from nikkipugh on Vimeo.

Talking to the furby or pressing the belly or back switches doesn’t break the loop, so at the moment it looks like the only way to interrrupt the cycle is to turnitonandoffagain.



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