04.) Firmware

It is time to load the PaperSynth firmware I created onto the ATTINY85 chip.  Of course, you could always create your own Arduino sketch and load it on as well.  Either way, you'll need to get the code from your computer onto the chip - here's how:

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.

Download and unarchive this paperSynth_v2_files.zip.  

Then, launch Arduino 1.0.1 (newer versions do not support the tone library.) You can download that here.

Open the Arduino ISP example.

You'll need to make a slight change to the code... find the heartbeat() function and change delay(40); todelay(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_v2_files folder as the Sketchbook location in Arduino.  Then restart Arduino.

Next, select the paperSynth_V2 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 circular "notch" faces upward.

The last step in building your synth is adding a battery to power it!