MIDI - RFduino - WS2812 Neo Pixels

Five Octave MIDI displayed on 60 LED Neo Pixel String

RFduino code MIDI_RFduino_WS2812 MIDI_RFduino_WS2812.ino // MIDI_RFduino_WS2812 // By Thomas Olson // teo20140220.01 // teo20140719.01 Modified for Arduino 1.5.7 // No complicated Pixel Library needed. // Tested with WS2812 6 pin and WS2812B 4 pin versions. // teo20140728.01 Modified for MIDI input // midi in - pin2 // midi out - pin3 const int ws2812pin = 6; const int nPIXELS = 60; const int nLEDs = nPIXELS * 3; uint8_t ledBar[nLEDs]; #define GREEN 0 #define RED 1 #define BLUE 2 #define LOWEST_NOTE 36 // What MIDI note starts the 5 octaves. #define nNOTES 128 // MIDI has 127 notes per MIDI channel uint8_t notes[nNOTES]; // Array of note velocities/LED PWM levels uint8_t midiCommand; uint8_t midiNote; uint8_t midiVelocity; void setup() { pinMode(ws2812pin, OUTPUT); digitalWrite(ws2812pin, LOW); // Initialize the ledBar array - all LEDs OFF. for(int wsOut = 0; wsOut < nLEDs; wsOut++){ ledBar[wsOut] = 0x00; } loadWS2812(); Serial.begin(31250,2,3); // setup midi on pin2,3 } void loop() { if(Serial.available()>2){ midiCommand = Serial.read(); //1st byte is MIDI command midiNote = Serial.read(); //2nd byte is MIDI note midiVelocity = Serial.read(); //3rd byte is note Velocity // uncomment the following to send the MIDI codes to the USB port. // Serial.end(); // Serial.begin(115200); // Serial.print(midiCommand, HEX); // Serial.print(": "); // Serial.print(midiNote, HEX); // Serial.print(": "); // Serial.print(midiVelocity, HEX); // Serial.println(": "); // Serial.end(); // Serial.begin(31250,2,3); switch (midiCommand) { case 128: // Only interested in MIDI Channel 0. notes[midiNote] = 0; break; case 144: // Only interested in MIDI Channel 0. switch(midiVelocity) { case 0: // Alternative to turn off a note notes[midiNote] = 0; break; default: // Turn on note. notes[midiNote] = midiVelocity; break; } break; default: // Ignore all other MIDI commands. break; } midi2bar(); } } // translate NOTE array to LED BAR array. Whatever alogrithm you want. // This one just sends to the blue LEDs on the 60 LED Strip WS2812B. void midi2bar(){ for(int note=LOWEST_NOTE; note < LOWEST_NOTE+60; note++){ ledBar[(note - LOWEST_NOTE)*3 + BLUE] = (notes[note]>>2) & 0xFF; } loadWS2812(); } void loadWS2812(){ noInterrupts(); for(int wsOut = 0; wsOut < nLEDs; wsOut++){ for(int x=7; x>=0; x--){ NRF_GPIO->OUTSET = (1UL << ws2812pin); if(ledBar[wsOut] & (0x01 << x)) { __ASM ( \ " NOP\n\t" \ " NOP\n\t" \ " NOP\n\t" \ " NOP\n\t" \ " NOP\n\t" \ ); NRF_GPIO->OUTCLR = (1UL << ws2812pin); }else{ NRF_GPIO->OUTCLR = (1UL << ws2812pin); __ASM ( \ " NOP\n\t" \ " NOP\n\t" \ " NOP\n\t" \ ); } } } delayMicroseconds(50); // latch and reset WS2812. interrupts(); }