Vtech Apple – Demo

Hey guy’s I just created and uploaded a quick video to show off my progress on the Vtech Alphabet Apple. Unfortunately I was having some issues with my portable amplifier so I ran it through the internal speakers but this should still give a good idea of what the bends I’ve completed so far can do. The demo starts off a bit slow but picks up after 1:20 or so. I also get into a really interesting glitch near the end of the video using the voltage starve.

If you want to have a look back at any of the previous posts they can be found here :

VTech Apple Part 1 – Kill Switch and Line Out

Vtech Apple Part 2 – Exploration and Pitch Adjustment

Vtech Apple Part 3 – Voltage Starve

Vtech Apple Part 4 – Body Contacts

Vtech Apple Part 5 – 555 Trigger Oscillator

 

 

VTech Apple Part 5 – 555 Trigger Oscillator

circuit bending, loop trigger, 555

I have to admit for some time I have been stalled with my Vtech Alphabet Apple circuit bending project. I love the toy aesthetically and have always felt like there should be more bends available then what I was able to find. However even after hours of experimenting and dissecting this toy I was left feeling somewhat underwhelmed with the results. Over the weekend though I brought it back out determined to turn it into a more functional instrument, and to do that I needed to create a trigger oscillator.

If you want to get caught up before going forward don’t hesitate to visit my previous posts on this toy:

VTech Apple Part 1 – Kill Switch and Line Out

Vtech Apple Part 2 – Exploration and Pitch Adjustment

Vtech Apple Part 3 – Voltage Starve

Vtech Apple Part 4 – Body Contacts

Since I hadn’t had any luck finding a loop on the board I moved on to less straight forward methods. I decided what I needed was a way to send a signal at repeating intervals to one of the contacts on the button matrix to trick the Vtech Apple into thinking a button was being repeatedly pressed and trigger a repeating sound. By generating this signal independently I could manipulate its frequency and control to suit my needs.

Once I had a clear definition of what I needed to get the job done the solution seemed all to clear, what I needed was a 555 timer. By setting up an astable 555 timer as a trigger oscillator I could route the square wave signal into the button matrix to repeatedly trigger the button (or buttons) of my choosing. Further by using a potentiometer I would be able to adjust the frequency of the square wave and therefore control the time between button presses as needed.

555 astable
This is a simple mock up of the circuit I used. Note that for this to work the positive voltage must be supplied by the toy itself and the ground must be share with the toy as well. This is easily accomplished by running the power from either the positive power connection on the Apple’s circuit board or directly from the kill switch installed in Part 1 . Just ensure it is connected at or past the kill switch so that the kill switch will remove power from the oscillator as well. Similarly the ground can be connected to any ground point on the circuit.

Astable 555 circuit
After testing my plan using a breadboard I put together this small 555 timer circuit on a scrap piece of perf board I had laying around from a previous project. I did my best to keep everything as small and compact as possible as my space inside the toy is somewhat limited. I’ve seen some circuit benders using what is called the “Dead Bug Method” in these situations to further minimize the size of the circuit. When building a dead bug circuit the components and connections are soldered directly to the pins on the IC rather than onto a piece of perf board. This can be an excellent way to shrink the circuit for those really tight fits but also leaves you with a more fragile product so since I could get away with using a board in this toy I did in order to get more stability and durability from the circuit. I will revisit dead bug circuits in a future post but in the interim there are many demonstrations of the method on YouTube if you deem it necessary.

Wiring 555 Oscillator
Once I had my 555  trigger oscillator circuit built the next step was to install it in my Vtech. I started out by planning positions and drilling holes for the potentiometer, switch and LED. Once these were in place I began the process of wiring the leads I had left on the 555 trigger oscillator circuit to their respective locations on the toy. On the diagram below I have marked the approximate paths of each wire upon installation. In planning this mod I did my best to limit the number of wires crossing between the back and front sections of the toy as these wires tend to get put under a lot of stress when the toy is being opened and closed. To achieve this I pulled power from my kill switch and sent ground directly to the negative terminal on the battery box. Since the switch and pot are mounted on the back portion this means only the pulse out wires have to cross over to the front half of the apple.

Wiring Vtech Apple

You may also notice that there are two pulse out wires leading from the switch to the button matrix. I used a 3 position on-off-on switch for this bend which allowed me to send the pulse to two locations based on the switch position (as well as nowhere in the off position) By connecting the opposing sides of the switch to different positions on the key matrix I am able to choose between two different buttons when running the oscillator. If you were so inclined and had the space to work with you could take this even further using a rotary switch or patch bay to allow you to select where the pulse was being sent. If there is a specific key you are after which you are not finding by touching the pulse to the solder points on the matrix try using your probe to connect sets of two points on the matrix together. If you find that this is necessary to get the input you desire this can be done by bridging the two points with a transistor and feeding the pulse into the base (more on that in a future article).

Finished Vtech Apple Loop
Once everything was wired I secured the 555 circuit and LED with hot glue, taped down all the loose wires and closed up the toy. I have to say after playing with it a bit I am really enjoying this modification. I’ve been able to produce a host of strange noises and effects and without having to use a hand to continually press the buttons I feel like I’m finally able to take full advantage of the other bends on this device. I’ve been having particular fun using the power starve to produce glitches in conjunction with the continuous oscillating noise produced by raising the rate of the 555 to high frequencies.

That’s all for today but I hope you guys have fun. Happy soldering!

Arduino – Getting Started

Arduino Midi

When I show off my strange circuit bent devices and synthesizers to musicians and friends of mine I often hear the same thing, “That’s awesome! … But how would you play it live?” This can be a vexing question, Some advanced or complex builds can be played in a live environment but especially as a beginner most of your devices will lack the versatility, reliability or control to be feasible as a live instrument. For this reason many Circuit benders and synth DIY enthusiasts rely on a process of recording and sampling the noises they create and using a sampler or MIDI controller to play them back with a reliable and easy to control interface. This is what I’d like to start exploring today.

Now I want to preface this project by saying that prior to beginning my research and experimentation for this build I had no experience working with the computerized side of music production. I have no background in coding outside of some rudimentary VB and HTML and though with my bands I have gone through the process of recording I have never been responsible for working with recording or mixing programs during this process. But I have an Arduino, and I’ve been led to believe that’s all anyone really needs in this crazy old world.

My goal is to start from the ground up over a series of articles looking at the various parts of this process and developing my own skills with the Arduino, Audio Mixing, MIDI and Recording as always with a strong focus on open source and DIY. Anyone could go out and spend a few grand to set up a recording studio and playback devices but that’s not what I’m about. I want to do it myself, on the cheap and I want to bring you along for the ride. Hopefully by the end we’ll all have a better understanding of how to capture and playback our strange creations.

I’ll still be circuit bending and building DIY synths but keep an eye out for upcoming articles on ways to incorporate the Arduino and software into our music creation process.

 

Speak And Spell 2 – Pitch Bend and Hold

Pitch Bend and HoldAfter a lot of experimentation and some frustration I feel like I am beginning to wrap my head around the Speak and Spell’s operation. This is by far the most complex toy I’ve attempted to bend and as such there has been something of a learning curve as I explored the circuit and began manipulating it. That being said because this is such a popular toy for circuit bending I’ve been able to find a wealth of information to supplement my own experimentation and give me direction as I delve into this project. Today I’ll take you through the addition of a pitch bend up knob and a hold switch to my Speak and Spell.

Pitch Bend

Speak and Spell Pitch BendFor the pitch up bend I actually used three points, I initially found and started experimenting with the pitch bend using the two points on the board above (The 2nd and 4th pins from the right on the synthesizer chip) but found I was able to get a greater range by connecting the third lug on the potentiometer through a resistor to the point shown on the smaller board on the right side. I used a 100K pot and a 15K resistor though I recommend experimenting with different values until you find what works best for you.

Hold

wp-1467656667322.jpgHold and loop functions can be some of the most fun bends on any device as the allow you to create a constant repeating noise from the device which you can modify or play with in all kinds of ways and from my research into the speak and spell I understand it has a number of these type of bends available. Above is shown the first of these bends I was able to locate. If the switch is flipped while the device is making a noise it will continue to make that noise until it is flipped back down. You can then modify the noise output using the pitch bend.

Voltage Divider Tool

Voltage Divider Test Tool Today while trying to sort out the buffers on a voltage divider for one of my circuit bending projects I grew frustrated with the ever growing pile of alligator clips and random resistors/potentiometers piling up on my desk as I experimented with different values. To help alleviate this chaos I spent the last half hour or so putting together a basic tool to help simplify the process.

What this tool allows you to do is attach your voltage in (Vin) to the left screw using an alligator clip. Next attach the center screw to the point the divided voltage is going. Finally you can connect the rightmost screw to ground (Or some other lower reference voltage). You can then adjust the knobs on either side to find the approximate buffer needed for either side of the voltage divider to give you maximum play from the potentiometer you install on your project. This device can also be used as a basic bend tester by attaching your two bend points to the center screw and one of the outside ones to test different resistance values with the bend.

Voltage Divider Testing

You can also play with the potentiometer values or use additional potentiometers to give you an even wider range of values. I would have liked to include a 1 or 2 meg pot and a 10K pot to each side had I had them on hand to give the tool more versatility.

Voltage DividerAbove you can see the schematic for this tool, as you can see it is a fairly simple build. The connectors at the bottom represent the screws for attaching clips on the final project. Please note if you prefer you can use binding posts or banana jacks in place of the screws depending on what is most convenient for you.

Divider WiringHere is the final wiring of the tool

Happy Canada Day

Happy Canada day to my Canadian readers, I will be away over the long weekend but will resume regular updates when I return next week.

Speak And Spell Part 1 – Set-up and First Glitch

Kill Switch, Output, Glitch, Speak And Spell

Today I wanted to show you guys another circuit bending job I’ve been working on that I’m pretty exited about. I found a working Speak And Spell at a local Value Village recently and have begun exploring and cannibalizing its innards for my own amusement. If you’ve so much as googled circuit bending you are likely familiar with the speak and spell and what it’s capable of (not to mention its sister devices the Speak And Read and Speak And Math), These devices can be turned into incredibly effective electronic instruments. I have never worked with one before but I wanted to take you guys along with me for the ride and share with you my victories and mistakes as we turn this device into something awesome.

If your looking for in depth schematics and diagrams of the circuit and possible bends, Casper Electronics offers a lot of great information.

Kill Switch And Output

circuit bending

The first thing I did to prepare the device for bending was to add a kill switch along the power connection and a switched output jack from the speaker connection. As these modifications are identical to what I did on my Vtech Alphabet Apple I will not go into to much detail here. Note the Speak and Spell does feature an on board headphone jack which could be used in place of the output jack it you prefer but I like having 1/4 inch jacks on all of my devices so I added one anyway.

The First Glitch

Speak And Spell - Glitch 1

Next up was to start exploring the circuit, I began triggering sounds from the keypad while touching a pair of probes to different pins on the board. After a little bit of searching I had come up with one which spewed bits of gibberish or random tones when the points were touched. I attached two lengths of wire and experimented with a few different control methods before settling on attaching them with a button.

A Silly Mistake

Speak And Spell - Mistake

Those of you who have worked with Speak And Spells before may have already noticed it but I made rookie error with my first glitch. I am slightly embarrassed about it but wanted to share it as a cautionary tale. When choosing the location of the button I began drilling from the back thinking that I was clear of the keypad, but in my excitement I did not check to see how far clear of it I was. Sadly the hole I drilled damaged the key matrix and has stopped many of the keys on the left side of the keypad from working. Luckily, enough keys still work that I can still turn the device on and trigger lots of noises but it has interrupted normal function of the device. No more scary robot hangman for me…

Salvaging Parts – Sears Clock Radio

sears clock radio - LXIEver since I started working with electronics it seems like I have a never ending flow of random electronics appearing in my workshop. Abandoned stereos and radios, Retro toys, Clocks, Printers, you name it. But what to do with all these broken down wrecks? In some cases if the devices are still in some kind of working order they can be hacked, repaired or circuit bent into usable order (either for their original purpose or some new one) but in the case of a device which is broken beyond usefulness such as this LXI series Sears brand clock radio I turn to salvage.

There are a host of excellent reasons for salvaging parts from old broken electronics. It is an excellent way to fill out your parts library and can often provide you with unique or interesting components you would not normally buy (or even be able to find in some cases). Also it can really help clear out rubble both in your work space and in local landfills. Instead of a shelf full of old stereos you could break them down, remove the casings and reduce them to a box or two of components. Further taking apart a device piece by piece can give you untold insights into how it was manufactured and how it works, you can learn vast amounts and sometimes interesting new tricks.

What to Salvage

Similar to choosing a circuit bending victim the ideal candidates for salvage are made before the year 2000 as generally items made after this point are almost entirely made up of surface mount components. Generally speaking the older the device the better, just make sure you aren’t ripping apart a valuable antique. As far as what types of devices to cannibalize, It really depends on the type of work you are doing. Since most of my projects work with sound synthesis and amplification I typically go after audio equipment like old stereo systems, radios, mixers, amplifiers, guitar pedals and so on. If you have a different focus though other items may be more useful tho. For instance if you are interested in robotics printers have an excellent array of motors and gearboxes ripe for the picking. The more you open things up the better a sense you will get for which devices are going to be rewarding for you and which are best left alone, as with most things the best way to learn is to start opening things up.

Lets Get Started

Make sure before you start tearing anything apart make sure the device is unplugged and all batteries are removed

LXI Sears Clock Radio - Case Removed

Removing the case from a device for the first time is like unwrapping a present, I usually spend some time after doing so to look over the device and see what parts I’m most interested in, already I can see there’s a good sized speaker on the left side, a couple interesting potentiometers and switches, and a host of trim pots, resistors, diodes, transistors and caps. There are also a few stranger radio parts connected to the tuner which have peaked my curiosity.

LXI Sears Clock Radio - Speaker and transformerBefore I get to deep I remove any parts which hang from the board such as the speaker, transformer and any battery clips to free the circuitry entirely from the casing. I discard the casing and begin removing any other mechanical or supplementary parts.

LXI Sears Clock Radio - Cassette Deck and TunerPictured above are the mechanical parts from the tape deck and tuner, I was able to get some good gears and a working motor from the tape deck. I’ve left the pulley system from the tuner intact as I feel I may be able to re purpose it down the road as a fine tuning knob for a potentiometer.

LXI Sears Clock Radio - BoardOnce you’ve got the main circuit board by itself you can begin de-soldering components using a soldering gun and a solder sucker or wick. Typically at this point I will add the circuit board to my “Board Bin” and remove the components as I need them but if you prefer or if there are specific components you are most interested in you can take them off immediately. Remember to test all components before using them elsewhere as sometimes certain parts will breakdown over time or through abuse the device may have taken in it’s lifetime.

5 Tools To Stay Organized

I’m working away on some exiting new projects but until I get them finished I wanted to share some quick ways that I use to keep my workstation organized. With thousands of small parts, endless types and colors of cable and a pile of specialized tools it can be very easy to watch your workstation descend into chaos. Today I’ll go over a few quick tips to help you keep things organized so you can spend less time searching for tools and parts and more time focusing on your builds.

1 – Component Shelves

Component Shelf

Component shelves can be purchased online from amazon or at most major hardware stores and I honestly can’t imagine my work area without them. I’d recommend purchasing a few of these as soon as you start exploring electronics, set up a sorting system and keep to it. This way instead of digging through a pile consisting of every resistor you own you can just reach out and grab it from the corresponding drawer.

2 – Wire Rack

Wire Rack

It doesn’t take long for your spools of wire to start unwinding and trailing around your workstation, the simple solution to this is to set up some kind of wire rack and place the spools onto it, this way you roll and unroll them with ease. There are commercially available wire racks though the one I use is actually an old broken lamp. Paper towel racks are also often very effective.

3 – Bins

Bins

For parts or devices too large for your component drawer I keep a number of bins of various sizes on selves around my workstation, Label each bin and sort items into them as necessary. I have large bins for things like cables, toys and “Devices for Salvage” then there are smaller bins for things like adapters, alligator clips and speakers.

4 – Tool Baskets

Basket

I keep a few baskets around my workstation which are where I store all of the common tools I use on a day to day basis so that they are at hand whenever I need them. In these baskets you can find things like pliers, wire strippers, angle cutters, a few screwdrivers and my solder remover.

5 – Small Containers

Containers

Small containers are great for holding all the hundreds of tiny screws you remove from devices as you take them apart, along with any other small parts that you remove and don’t want to lose. Typically I get these from dollar stores though daily dosage containers from pharmacies are excellent as well.

 

Awesome LEDs

Vtech LEDs

Whether its a circuit bent monstrosity or a simple oscillator, nothing brings a project to life quite like a couple LEDs. Today I wanted to show you an easy trick I picked up from a friend to give the LEDs you add to your projects a clean and professional look without having to spring for fancy lights or sleeves. All you need is some hot glue, a shallow nut or washer and some electric tape.

Start out by drilling a hole where you want the LED to be, This hole should be bigger than the LED itself and around the same size or slightly larger than the hole in your nut or washer. Once the hole is drilled line the washer or nut up with it and place a piece of electric tape over it. Take a moment to ensure the electric tape is taught and smooth over the hole in the nut and that it did not move when you were taping it down (It should still be lined up with the hole in your project).

Next we want to turn over or open up the device and pour a generous amount of hot glue into the hole from the back, allow it to heap up a bit on the inside of your device, before the glue has a chance to solidify push the LED into the hot glue, do your best to stop it just shy of pressing into the tape on the other side so there is still some glue between it and the tape. Once it is in place allow the glue to dry for a few moments, If you would like you can take this opportunity to wire the LED to the circuit (If you haven’t already)

Once the glue has completely dried gently remove the tape, You may need to use an Exacto knife to remove any excess glue leaving a smooth surface filling the hole in the nut. Since the glue is translucent when the light is turned on the entire hot glue plug will glow giving the appearance of a large flat bulb.