arduino-raspi-puredata-synth

https://youtu.be/tXrLTHSiED0

What you'll need

Assemble all the materials first before starting.

For the Arduino

• Arduino Uno
• Push button
• 1x 12k Ohm resistor
• 3 different coloured wires

For the Raspberry Pi

• Wifi capable Raspberry Pi (e.g. Pi 3+ or Pi Zero W)
• 8GB (or larger) SD Card

Optional sound output

Skip these items if you have one of the larger models of Raspberry Pi with onboard sound output.

• Breadboard
• 2x 0.033 uF capacitors
• 2x 10 uF capacitors
• 2x 270 Ohm resistors
• 2x 150 Ohm resistors
• 1x
• 3x different coloured wires

Other items

• Laptop or computer to program Arduino
• HDMI screen for Pi
• Keyboard + mouse for Pi

Assembling and programming

Arduino

A simulation and diagram of the arduino component is available here.

• Download the Arduino project file and open with the Arduino IDE
• Connect your Arduino to your computer and download the code to the device.
• Connect the button as shown in the Tinkercad link.

Raspberry Pi

• Start by installing NOOBS on the SD card. Follow the instructions on the Raspberry Pi website. Select Raspbian for your operating system.
• Once the installation is complete, we're going to start installing Pure Data. Open a terminal and run the following commands:

sudo apt-get update
sudo apt-get install puredata
sudo apt-get install pd-comport

• Installing the PD_Arduino package is a little trickier. Open the web browser on your Pi and [download the .zip from GitHub]. Once complete, extract the contents to /usr/lib/pd/extra/.

• Enable your new Pure Data packages.

  • Open Pure Data from the Audio tab.
  • Go to File > Preferences > Path ..
  • Select 'New' button and add the paths for your Purde Data packages. They should be /usr/lib/pd/extra/comport and /usr/lib/pd/extra/PD_Arduino.

• Download the .pd file in this repository and put it in your user Home (/home/pi).

• Configure Pure Data to start headless when you boot your Pi.

  • Create a new Bash script called /home/pi/bin/pd_start:

  pd -nogui /home/pi/squarewaver.pd &
  

  • Enable the script to run with /home/pi/bin/pd_start
  • To run the script at startup add the following line to /etc/rc.local:

  /home/pi/bin/pd_start
  

  Starting the synth

  • Unplug your monitor, mouse, keyboard from the Raspberry Pi.
  • Connect the sound output to an appropriate device.
  • Connect the Arduino to your Pi via the USB port.
  • Reboot your Pi.
  • Once the Pi has booted, you should be able to get sound out by pressing the button connected to the Arduino.

Sound output from Raspberry Pi

This is an optional step and is only needed if you have a Pi Zero model. You can find a great tutorial here.