2.Note-Range-LEDs.ino

2.Note-Range-LEDs

This example demonstrates the use of LEDs that respond to incoming MIDI note events. The LEDs are driven by a 74HC595 (or equivalent) shift register.

Boards: 🛈

AVR, AVR USB, Nano Every, Due, Nano 33 IoT, Nano 33 BLE, UNO R4, Pi Pico, Teensy 3.x, ESP32, ESP8266

Connections

• SS: 74HC595 ST_CP
• MOSI: 74HC595 DS
• SCK: 74HC595 SH_CP

Connect eight LEDs (and series resistors) between the outputs of the shift register and ground.

Remember to connect the enable pin of the shift register to ground and the master reset pin to Vcc in order to enable it.

Behavior

If a MIDI Note On event for note 0x3C (C4 or middle C) is sent, the first LED will light up, if a Note Off event for that note is sent, the LED will turn off.
If a MIDI Note On event for note 0x3D (C#4) is sent, the second LED will light up, and so on.
(A Note On event with a velocity of zero also counts as a Note Off event.)

Mapping

Route the MIDI output of a MIDI keyboard to the Arduino's MIDI input. Then play some notes between middle C and middle G on the keyboard. The LEDs should light up when you press the keys.

Written by PieterP, 2019-10-09
https://github.com/tttapa/Control-Surface

 
// Include the library
#include <Control_Surface.h>
 
// Instantiate a MIDI Interface to use
USBMIDI_Interface midi;
 
// Instantiate a shift register as output for the LEDs
SPIShiftRegisterOut<8> sreg {
  SPI,      // SPI interface to use
  10,       // Latch pin (ST_CP)
  MSBFIRST, // Byte order
};
 
// Create a range of LEDs that listens for MIDI Note messages, turning on and off
// the LEDs connected to the eight output pins of the shift register
NoteRangeLEDs<8> leds {sreg.pins(), MIDI_Notes::C[4]};
 
// Initialize the Control Surface
void setup() {
  Control_Surface.begin();
}
 
// Update the Control Surface
void loop() {
  Control_Surface.loop();
}