Circuit bending is the art of creatively short circuiting low voltage hardware to create interesting and unexpected results. It’s generally applied to things like Furbys, old Casio keyboards, or early consoles to create audio and video glitches for artistic effect. It’s often practiced with a random approach, but by bringing in a little knowledge, you can get astounding results. [r20029] decided to apply her knowledge of CD players and RAM to create this glitched out Sony Discman.
We’re all familiar with record-your-own-message greeting cards. Generally they’re little more than a cute gimmick for a friend’s birthday, but [dögenigt] saw that these cards had more potential.
After sourcing a couple of cheap modules from eBay, the first order of business was to replace the watch batteries with a DC power supply. Following the art of circuit bending, he then set about probing contacts on the board. Looking to control the pitch of the recorded message, [dögenigt] found two pads that when touched, changed the speed of playback. Wiring these two points to the ears of a potentiometer allowed the pitch to be varied continously. Not yet satisfied, [dögenigt] wanted to enable looped playback, and found a pin that went low when the message was finished playing. Wiring this back to the play button allowed the recording to loop continuously.
[dögenigt] now has a neat little sampler on his hands for less than $10 in parts. To top it off, he housed it all in a sweet 70s intercom enclosure, using the Call button to activate recording, and even made it light sensitive with an LDR.
Check out the video under the break.
One of the classics of circuit bending is to mess around with the clock chip that drives the CPU in simple noise-making toys. [Goran] took this a step further with his Furby hack. Skip down to the video embedded below if you just want to see the results.
After first experiments modifying the Furby’s clock with a string of resistors (YouTube), [Goran] decided to opt for more control, overriding the clock entirely with a square wave coming out of an Arduino. And then, the world became his oyster.
The Furby’s eyes were replaced with ultrasonic distance sensors, and what looks like a speaker was hot-glued into its mouth. Since this particular Furby only “talks” when you pull its tail, he naturally wired in tail-switch control to boot. As [Goran] suggests, a light show is the obvious next step.
If you haven’t pulled apart an electronic toy and played around with glitching it, you don’t know what you’re missing. We’ve got a classic intro to circuit bending, as well as projects that range from the simple to the ridiculously elaborate. It’s a fun introduction to electronics for the young ones as well. Grab a toy noisemaker and get hacking.
Circuit-bending is tons of fun. The basic idea is that you take parts of any old electronic device, say a cheap toy keyboard, and probe all around with wires and resistors, disturbing its normal functioning and hoping to get something cool. And then you make art or music or whatever out of it. But that’s a lot of work. What you really need is a circuit-bending robot!
Or at least that’s what [Gijs Gieskes] needed, when he took apart a horrible Casio SA-5 and grafted on enough automatic glitching circuitry to turn it into a self-playing musical sculpture. It’s random, but somehow it’s musical. It’s great stuff. Check out the video below to see what we mean.
We also love the way the autonomous glitching circuit is just laid over the top of the original circuitboard. It looks like some parasite out of Aliens. But with blinking LEDs.
For a lot of us some sort of audio circuit was our first endeavor into electronics. Speak and Spell, atari punk console, LM386 in a mint tin, sound familiar? If not, you should do yourself a favor and knock out a couple of those simple projects. For those of us who have done a bit of what the kids are calling circuit bending, [Nickolas Peter] brings us a familiar hack with his Patient Alpha project. You can see a time-lapse video of the build process and a short demo in the video after the break.
[Nickolas] did a few mods to his 2013 Executor key fob; the obligatory potentiometer for resistor swap is always a crowd pleaser. Adding an audio out via 3.5 mm jack is something that some of us wouldn’t have thought to include, but it lets the Executor scream into your serious audio gear for maximum eargasms. It’s worth mentioning that [Nickolas] does a good job with this hack’s finished look, albeit he started with a product in an enclosure he still goes to the trouble of custom fitting all his bits in an aesthetically pleasing way. And then he made a second.
We have covered circuit bent projects aplenty: from an old school take on circuit bending to one with a ratking of wires built on a proper bit of audio kit. Dig out your soldering iron and dig in.
A friend from the newly founded Yeovil Hackerspace introduced me to a device known as “The Kraakdoos” or cracklebox.
The cracklebox is an early electronic instrument produced by STEIM in the 1970s. The instrument consists of a single PCB with a number of copper pads exposed on one side. The player touches the pads and the instrument emits… sounds which can perhaps best be described as squeeze and squeals.
While the cracklebox was original sold as a complete instrument, the device has been reverse engineered, and the schematic documented. What lies inside is quite fascinating.
The heart of the cracklebox is an ancient opamp, the LM709. The LM709 is the predecessor to the famous LM741. Unlike the 741 the 709 had no internal frequency compensation. Frequency compensation is used to intentionally limit the bandwidth of an opamp. As input frequency increases, the phase shift of the opamp also increases. This can result in undesirable oscillation, as the feedback network forms an unintentional phase-shift oscillator.
Most modern opamps have internal frequency compensation, but the 709 doesn’t. Let’s see how this is used in the cracklebox:
Rather than using the frequency compensation pins as intended the cracklebox just routes them out to pads. In fact the cracklebox routes almost all the pins on the opamp out to pads, including the inverting and non-inverting inputs. A single 1MOhm feedback resistor is used in a non-inverting configuration. However reports suggest the instrument can work without a feedback resistor at all!
Circuit bending is the process of taking a small electronic toy or musical instrument, soldering wires to pads on the PCB, and hoping the sounds it produces will be cool. It’s not a science by any means, and any good, weird sounds you’ll get out of a Speak ‘N Spell or old MIDI keyboard are made entirely by accident or hours and hours of experimentation.
[Alpha Charlie]’s entry for the Hackaday Prize is the most technologically advanced circuit bending you’ll ever see. He’s using an old digital beat box, the Roland TR-626, with computer-controlled wires between random pads on the PCB.
Until now, you could tell how technically adept a circuit bender was simply by how many switches were on the circuit-bent instrument. [Alpha Charlie] doesn’t need switches. Instead, he’s using a few crosspoint switch ICs to connect different pins and pads on the TR-626’s PCB with an Arduino. All of this is controlled by a touchscreen display, and experimenting with the circuit is as simple as pushing a few buttons. Each ‘bend’ is computer controlled, and can be saved and recalled at will.
Of course, circuit bending doesn’t do anyone any good if it sounds like crap. [Alpha Charlie] doesn’t have to worry there. In the video below, he’s getting some very unique sounds that sound like a choir of angels to dorks like myself that listen to Nintendo music.