6.MAX7219-NoteLED.ino

6.MAX7219-NoteLED

This example demonstrates the use of LEDs that respond to incoming MIDI note events. The LEDs are driven by a MAX7219.

Boards: 🛈

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

Connections

• SS: MAX7219 CS
• MOSI: MAX7219 DIN
• SCK: MAX7219 CLK

Behavior

If a MIDI Note On event for note 0x3C (C4 or middle C) is sent, the first LED of the MAX7219 will light up, if a Note Off event for that note is sent, the LED will turn off.
(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 a middle C on the keyboard.

Written by PieterP, 2020-03-24
https://github.com/tttapa/Control-Surface

 
#include <Control_Surface.h> // Include the Control Surface library
 
// Instantiate a MIDI over USB interface.
USBMIDI_Interface midi;
 
// Instantiate a MAX7219 with the SPI slave select pin as latch pin
// There's just 1 MAX7219 in the chain, if you have more of them daisy-chained
// together, you can increase the template argument (between angled brackets)
MAX7219<1> max7219 {SPI, SS};
 
// Instantiate the LED that will light up when middle C is playing
NoteLED led {
  max7219.pin(0),                // First pin of the MAX7219
  {MIDI_Notes::C[4], Channel_1}, // Note C4 on MIDI channel 1
};
 
void setup() {
  Control_Surface.begin(); // Initialize Control Surface
  // No need to initialize the MAX7219 or to set pinModes, all of this
  // is handled by Control Surface.
}
 
void loop() {
  Control_Surface.loop(); // Update the Control Surface
}