using the DART_MOBO

  • the basic circuit of a DART controller is equipped with 48 INPUT pins and 32 OUTPUT pins
    • INPUT pins are used to connect modifiers: pushbuttons, potentiometers and sensors.
    • OUTPUT pins are used for LEDs.
  • We recommend using Arduino LEONARDO to do these assembly exercises, because it is much faster to use for MIDI projects.

INPUT and OUTPUT pins numbering on the DART_MOBO


INPUT and OUTPUT circuit on a breadboard

  • The DART circuit is based on MUTIPLEXERS (4051), and SHIFTERS (74HC595)
    • Multiplexers – used to enable the 48 INPUT pins.
    • Shifters – used to enable 32 OUTPUT pins.


Basic MODIFIERS: Pots, buttons and LEDs

  • PUSHBUTTONS and POTENTIOMETERS can be  connected to any INPUT pin
  • Pay attention to  DART_MOBO power lines
    • each modifier or LED must be correctly connected to the +5V power line and to the GND line.
    • LEDs are protected by a 220 Ohm resistor. The resistor value can be higher for UltraBright LEDs.


BASIC MODIFIERS on a breadboard

this example on breadboard is for illustrative purposes only. For those who want to create a DART controller, we recommend using a DART_MOBO kit


TESTING and MONITORING the MIDI activity.

  • Upload the DART_SKETCH  onto the Arduino board.
  • Run the DART_EDITOR app and choose the right MIDI in/out ports at startup.
  • Any action on the modifiers connected to the DARTMOBO, can now be monitored on the EDITOR.
    • A BUZZER SOUND is audible anytime a button is pressed or a pot is turned. This sound feedback can be disabled by clicking on SOUND button
    • The MIDI-MONITOR is giving a visual feedback of the MIDI data stream. A NOTE message is received at button pressure. A Control-Change (CC) message is received at potentiomenter motion.


 LEDs react on buttons pressure

  • As a new DART_Sketch is uploaded on the Arduino board, the system will work in AUTODETECT mode, meaning that
    • pushbuttons are automatically detected and set to control NOTE messages.
    • Potentiometers are automatically detected and set to control CC messages.
    • LEDs outputs are linked to pushbutton inputs, according to the input number (example: a button on input 3 controls a LED connected on output 3)
  • the AUTODETECT assigns a different MIDI message to each modifier, in order to avoid duplication and facilitate the immediate use of the newly created device.
  • the modifiers can also be directly attached to the arduino inputs, without using the MULTIPLEXER, as in the case of the DART_VECTOR in which only 3 multiplexers are used.

The AUTODETECT mode is good for very basic projects but to have complete control over all the functions that the DART system provides, we will have to learn how to create our own custom presets, using the DART_EDITOR