This circuit changed my life. That's no hyperbole. Let me tell you a story-
When I was a kid I really wanted to understand electronics. I loved taking things apart and circuit boards fascinated me. One year my folks bought me a Radio Shack 200-in-1 Electronics Lab for Christmas. While I had a blast following the direction and building projects, I was a little too young to take it seriously and learn the theories behind them.
Over the years I would periodically decide that it was time to get serious and 'learn electronics'. I'd get a book from the library and start reading, but I was soon lost in a sea of theory and formulas with no real-world application. After a week or two I'd decide that electronics was not for me and return the books.
One day I was reading the Make magazine blog. I saw a post from Colin Cunningham about the Atari Punk Console. This circuit originally appeared in a book by Forrest M. Mims. He called it the stepped tone generator. Some folks built it and noted the similarity between its sound and early video games, so it was dubbed the Atari Punk Generator.
I watched a video of the project and was impressed by how simple it was to build and how cool it sounded. After a quick trip to Radio Shack and an hour or so of really bad soldering I had a cool little sound gizmo. I was hooked. I bought more chips and a breadboard. I bought a variety pack of resistors and capacitors. I looked online for more 555 based audio circuits and tried them out. I bought a heat gun from Harbor Freight and stripped discarded circuit boards. I soon had enough parts to build most of the circuits I found.
Something cool happened. I'd build a circuit and then I'd swap out resistors or capacitors for ones with different values. This had an effect on the sound it produced. Soon, resistors and capacitors began to make sense. This opened the door to transistors, chips, diodes, pots and a bunch of other amazing parts. I was soon building more complex projects that made even more complex sounds. Without really trying, just playing around, electronics started making sense!
Soon, all those baffling formulas and theories started making sense, too. Why didn't those books just show me how build cool things and let me figure out the rest? I had an epiphany- no one wants to 'learn electronics', they want to learn how to do things with electronics. This applies to almost any STEM discipline. Find the interest and work the science in. Like to cook? Let's learn the chemistry behind food and cooking. Like video games? Let's learn to program our own. Want to play music? How about making your own synthesizer, drum machine, amp or effects pedals?
When I was a kid I heard Joseph Campbell's quote about following your bliss and opening doors. I thought it was some feel-good hippie BS. Now it makes perfect sense- only after I 'followed my bliss' (making noise that sometime resembles music) did the 'doors' of understanding electronics begin to open. Now I spend most of my time building electronic musical instruments and having a lot of fun.
Here's my version of the Atari Punk Console. I hope it inspires you the way it inspired me. Who knows? You may end up with a soldering bench and rolling parts cart in your living room, too.
Step 1: Parts
The Atari Punk Console needs the following parts-
1 170 hole breadboard
2 555 timer chips
1 1k resistor
2 330ohm resistors
1 .047uf capacitor
1 .1uf capacitor
1 10uf capacitor
1 9v battery connector
1 plastic base board
You can get all of this at Radio Shack or Fry's, but if you want to save money or create multiple kits you should check out eBay's sellers overseas. I get 100 555 timers for under $10 and 1,000 resistors for a few bucks.
Step 2: Chips and Pots
First we'll install the chips and potentiometers (pots). See the pics above for more details. Chips usually have an indentation in one end. This marks the 'top' of the chip. The pins are numbered starting with the top left and continuing counterclockwise around the edge of the chip.
Step 3: Wiring Up Chip A
Writing out the steps of building a circuit is like writing the score of a Skrillex song. The best way to explain the circuit is visually. See the above pics for the steps involved in building the circuit.
Step 4: Wiring Chip B
Chip B is wired next. Be careful to have the right polarity on the 10uf cap. Electricity can only flow in one direction through a capacitor. Make sure that the side of the 10uf cap with the stripe connects to the empty row where the speaker connects.
Step 5: Connecting the Speaker and Battery Connector
The speaker and battery connector have stranded wires. These are made up of many thin wires. This makes them hard to use on a breadboard. It helps to twist the individual strands together and use a jumper wire to hold them in the hole. See the above pics.
Step 6: Mounting the Breadboard and Battery
The base plate holds everything in place to prevent things from coming loose.
Step 7: Testing the Circuit and Making Noise
Now it's time for the moment of truth. When you plug the battery in, the speaker should make a sound. By turning the two pots the sound should change. If you get no sound go back and check all of your connections. Don't give up!
Turning the right side pot causes individual notes, created in 'steps'. Turning the left side pot controls how close those steps are to each other and how close the pitches are. Twiddling the pots can create various video game-like sound effects.
Now try this- disconnect the right side pot and plug in the photoresistor in it's place, between the jumpers from pins 7&8 of chip A. Now put the Atari Punk Console in a bright spot and wave your hand back and forth over it. The amount of light hitting the photoresistor will now control the pitch of the APC.