I wasn't able to attend Maker Faire Milwaukee last year because I was (literally) exhausted after TEDx UWMilwaukee and the talk I gave there. I really regret missing it - so this year I wanted to do something special as part of the event.
I decided on hosting a workshop, and that I'd feature the ATTINY85 chip. I've used it in a few projects - it is inexpensive and quite versatile, with 3 analog pins and two pwn pins. It can also run without much additional hardware - and on a 3v coin cell battery!
I decided, rather than traditional breadboarding, I'd take inspiration from Jie Qi and use copper foil tape on paper. Below full build instructions for the project - I am hosting it here both for people who attended the workshop, but also for anyone else interested in making a paperSynth circuit.
If you attended this workshop, and are interested in my other projects, please visit
Step One: Aquire Materials
BILL OF MATERIALS:
For building the paperSynth:
1.) Force Resist Sensor: $6.00 from Digikey, here.
2.) Piezo Speaker: $0.60 from Digikey, here.
3.) ATTINY85 Chip: $1.50 from Digikey, here.
4.) 8-pin IC Socket: $0.17 from Digikey, here.
5.) Potentiometer: $6.40 from Amazon, here.
5.) 3mm LED: $0.23 from Digikey, here.
6.) 200 Ohm Resistor: $0.021 from Digikey, here.
7.) 1k Ohm Resistor: $0.10 from Digikey, here.
8.) Coin Cell Battery: $8.45 from Amazon, here.
9.) 1/8 Inch Copper Foil Tape: From Amazon, here.
9.) 1 Binder clip
10.) Craft Board or Card Stock
11.) paperSynth Schematic/Template: See below
12:) Spray Mount: $9.41 from Amazon here.
13.) Super Glue: $5.56 from Amazon, here.
1.) soldering iron and solder
2.) scissors or x-acto knife
And if you havent programmed an ATTINY85 before, you might need these:
1.) Arduino Uno Board: $21.00 from Amazon, here.
2.) Breadboard: $4.66 from Amazon, here.
2.) Jumper Cables: $7.50 from Amazon, here.
3.) 10UF Electrolytic Capacitor, $1.05 from Digikey here.
1.) Arduino 1.0.1 (Newer versions don't support the ATTINY core we'll be using):
2.) paperSynth files (ATTINY board profile, and the paperSynth code):
3.) paperSynth Template:
For the IC socket, I am using the "Squashed bug" technique. You'll want to bend the pins on the socket to roughly match the template.
Step Two: Assemble Template:
Using spray mount, mount the template to craft board or card stock. Be sure you spray in a well-ventilated area!
Trim with scissors or x-acto knife.
Use a narrow blunt object to score the fold lines - this will make it much easier to fold precisely later on. I used the head of a small nail - alternatively you could use a folded paperclip or a ballpoint pen tip.
Step Three: Create Copper Traces
Next, place copper foil traces along the light grey paths on the template.
After applying the tape, use a credit card or the back of your thumb nail to smooth the tape down:
Be sure to overlap the corners of each trace - this will make soldering easier.
This is the most time consuming part of the project - it took me around 30 minutes to trace each path with tape - though I took my time so it would look pretty :)
Step Four: Solder Traces
Next, join the overlapping traces on the corners with solder.
Step Five: Populate!
Before any glueing or soldering, lay the components out on the circuit and make sure you understand where each goes. They are each labeled on the template (available above).
I like to first mount my components to the board with super glue. Krazy Glue with the brush applicator is my all-time favorite. This makes soldering easier, but also helps hold the components to the board so we're not just relying on solder alone when we use it.
Once your components are tacked down, solder them!
Step Six: Programming the ATTINY
I learned to program an ATTINY using an Arduino Uno as an in-system programmer from a tutorial by High Low Tech.
I discovered the ATTINY85 core that includes the tone library here.
I am going to include my own instructions here, however.
To use an Arduino UNO as an ISP, create the above circuit on a bread board.
***When it comes time to program the chip, you'll need to put a capacitor between reset and ground to keep the UNO from resetting after upload. For now, leave that component out.
Unarchive the paperSynth_v1_files.zip. Then, launch Arduino 1.0.1
Open the Arduino ISP example.
You'll need to make a slight change to the code... find the heartbeat() function and change delay(40); to delay(20);
Before uploading the ArduinoISP code, be sure to select Arduino Uno as your board.
Now that we have transformed our Arduino Uno into an ISP, it is time to load our code and board profile for the ATTINY85 chip...
First, set the paperSynth_v1_files folder as the Sketchbook location in Arduino. Then restart arduino.
Next, select the PaperSynth_simple sketch from the Sketchbook menu.
And select "Arduino as ISP" from the Programmer menu.
Now we can set our board to ATtiny85. (It should show up as an option after we set the sketchbook directory ealier). Be sure to select "ATtiny85 @ 8MHz (internal oscillator).
***At this point, add the capacitor between the RESET and GND pins.
Before we upload the paperSynth code to the ATTINY85, we need to burn the bootloader for the 8MHz setup. You only need to do this step once (per chip).
Now it is time to program the tiny! Select "Upload Using Programmer" from the File menu.
You may see this error during the bootloader burn or uploading the sketch. It is okay, you can ignore it! If it says "Done uploading" you should be good to go!
Congratulations! You have Programmed your ATTINY85.
Insert the ATTINY85 chip into the socket. Be sure to orient the chip so that the little "notch" faces upward.
Finally, place a 3v coin cell battery negative-lead-down on the template, and fold the corner down over it.
Place your binder clip over the corner to ensure contact between the copper foil leads and the battery terminals.
You've done it. Enjoy your paperSynth Circuit!
Step Seven: Jam Session
Step Eight: Custom CodeNow that you've built the circuit, you may be interested in creating your own code. I, myself, would like to create a version that limits tones to a pentatonic or chromatic scale so that I can actually play alongside other instruments. When I create this (hopefully in the near future), I'll upload it here.
This ATTINY85 diagram might help when writing code for this circuit:
Thanks for reading, and hopefully you are now in the middle of an intense paperSynth jam session!