Electronic Micro Projects by John Talbert
  • © 2021 jmt 0

Stacks Image 12
Projects with Arduino Boards

Here is what the Arduino site at www.arduino.cc says about its product:

Arduino is an open-source electronics platform based on easy-to-use hardware and software. It's intended for anyone making interactive projects.

Arduino senses the environment by receiving inputs from many sensors, and affects its surroundings by controlling lights, motors, and other actuators.

You can tell your Arduino what to do by writing code in the Arduino programming language and using the Arduino development environment.


Sensors with the Pro Micro

Sixteen sensor boxes with USB MIDI or USB Serial connections. Built with the Arduino Pro Micro board, one of Arduino's smallest boards, and the TeeOnArdu software package. These are simple devices for direct connection to a computer via USB for use with programs such as Max/MSP. Sensor specs and Arduino code are included in the PDF.

  • Accelerometer
  • Foot Pedals
  • Flex Sensor
  • Force Sensing Resistor
  • Gesture
  • Joystick
  • Light sensors
  • PIR
  • SoftPot
  • Sound Detector
  • Switch Box
  • Tilt
  • 9 DOF
  • Ultrasonic Distance sensor

Reprogramming these boards can be difficult. The serial lines used for MIDI must be interrupted somehow to let a new program be uploaded over the same lines. After hitting the LOAD button in the Arduino IDE app wait for the Compile to finish and then momentarily ground the RESET pin before the LOAD starts. The timing of this is critical and may take several attempts.

Music Keyboard on the Pro Micro

This 3-Octave music keyboard can accurately produce two notes at a time. An Arduino Micro is used to scan 12 chromatic note switches and three octave buses.

There are three outputs: a USB serial output (also used to power and program the keyboard), a MIDI output, and a squarewave audio output.

Pro Micro Synthesizer

A 4-voice Pro Micro Arduino Synthesizer from 4 output pins producing squarewaves combined into one output using NOR Gate and Mixer circuitry. Programmed to use the Arduino tone() function and routines that toggle the pin outputs at multiples of the main program loop() speed.

One program uses pots to control 4 voice frequencies. Another uses MIDI Input to record and playback 3 polyphonic voices.

Includes a unique analog Fuzz box circuit on one of the voices that uses an Arduino output to enhance the distortion.

SID Radio with Pro Micro

The SID Majestic Radio is basically a classic Commodore game synthesizer chip, the SID6581, controlled by an Arduino Pro Micro microprocessor combined with a "Radio Music" Euro Module.

An Arduino Template program provides all the functions needed to access the chip's 29 registers that control the 3 Pulse/Triangle/Sawtooth synthesizer voices and modulation patching.

A forth modulating voice is added from the Arduino. Several switches, pots, and soft pots can be programmed as controllers.

Teletalk with Uno

The AY Teletalk box is basically a classic 1970's arcade game synthesizer chip, the AY-3-8912, controlled by an Arduino Uno microprocessor.

An Arduino Template program provides all the functions needed to access the chip's 14 registers that control the AY's 3 squarewave/noise voices.

A forth voice comes from the Arduino. Each voice has a volume pot and modulation capabilities. Three switches and slide pots can be programmed as controllers.

AYSID with the Mega

The classic SID Commodore game synthesizer chip is combined with the 70's AY-3-8912 arcade game sound chip and placed inside an old Teletalk office intercom box.

An Arduino Mega provides programmable access to all the synth parameters of both chips along with a full complement of controllers to twiddle those paramenters.

The controllers include MIDI I/O, 6 sliders, 6 light sensors, 4 switches, a soft pot, and volume controls for the voice outputs.

Euro Mega

The Euro Mega Controller is a programmable interface built in the Euro Rack format. All its devices are connected to an Arduino Mega 2560 microcontroller.

It can generate and read audio signals, pulse signals, analog synthesizer control voltages, and MIDI. As such it is an ideal interface between a programmable Arduino and an Analog Synth.

It includes 6 Pulse Inputs, 6 Pulse Outputs, 6 Control Voltage Inputs, 6 Control Voltage Outputs, One 8-bit DAC, MIDI I/O, 5-Input Diode Modulation Gate.

DSP on the MKR-Zero

The MKR_Zero is a SAM D21-based 32-bit microcomputer board with greatly expanded capabilities in speed and memory space over older Arduino boards. With an SD card slot and both a 12 bit ADC and 10 bit DAC it is the first Arduino to approach Digital Signal Processing capabilities.

This box was built as a platform to explore audio and MIDI processing. To accomplish this the MKR_Zero was expanded to include an upgraded 16-bit DAC, a MIDI Input and Output interface, several programmable switches and slide pots, and an audio mixer with pulse wave inputs, modulation, and feedback .