NeoTrellis Setup

The Live Launcher consists of two pieces of software:

  • Neotrellis firmware written in the Arduino IDE
  • Live Launcher device plugin for Ableton Live

Download & install the Arduino IDE if you haven't already and add support for Adafruit boards via instructions here.

Assemble the NeoTrellis M4

Follow the instructions in this guide to assemble and test your NeoTrellis M4. Once you've got it up and running, you can move on to programming.

Install the Adafruit NeoTrellis M4 library

Open Arduino, go to Sketch -> Include Library -> Manage Libraries … and type NeoTrellis in the search field of the window that appears. Install the Adafruit NeoTrellis M4 Library that appears in the search results.

Create the Live Launcher sketch

Create a new sketch and delete the default template code which appears within it. Copy the code below, paste it into that new sketch, and save it as Live_Launcher (or whatever name you see fit).

/* Live Launcher - Ableton Live controller for Adafruit Neotrellis M4
    by Collin Cunningham for Adafruit Industries
    https://www.adafruit.com/product/3938
*/

#include <Adafruit_NeoTrellisM4.h>

#define WIDTH      8
#define HEIGHT     4
#define N_BUTTONS  WIDTH*HEIGHT
#define NEO_PIN 10
#define NUM_KEYS 32
#define SERIAL_TIMEOUT 1000  //time before giving up on incoming serial data
#define COLOR_DATA_LENGTH 98   //number of total bytes to expect in incoming color data 
//4 bytes per color * 32 buttons = 128 bytes + 2 header bytes = 130 bytes total
#define BUTTON_DATA_LENGTH 5  //clip playing status message for each button
#define PULSE_DURATION 350  //length of 'now playing' pulse

unsigned long readTime; //time we start reading serial buffer
unsigned long lastPulseTime;
bool pulseOn = false;
uint8_t packetbuffer[COLOR_DATA_LENGTH]; //store incoming serial data
uint8_t colors[96];

Adafruit_NeoTrellisM4 trellis = Adafruit_NeoTrellisM4();

const byte ROWS = HEIGHT; // four rows
const byte COLS = WIDTH; // eight columns
byte trellisKeys[ROWS][COLS] = {  //define the symbols on the buttons of the keypads
  {1,  2,  3,  4,  5,  6,  7,  8},
  {9,  10, 11, 12, 13, 14, 15, 16},
  {17, 18, 19, 20, 21, 22, 23, 24},
  {25, 26, 27, 28, 29, 30, 31, 32}
};
byte rowPins[ROWS] = {14, 15, 16, 17}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {2, 3, 4, 5, 6, 7, 8, 9}; //connect to the column pinouts of the keypad
Adafruit_Keypad customKeypad = Adafruit_Keypad( makeKeymap(trellisKeys), rowPins, colPins, ROWS, COLS); //initialize keypad
extern const uint8_t gamma8[];

boolean pressed[N_BUTTONS] = {false};        // Pressed state for each button
uint8_t playing[N_BUTTONS] = {0};        // Playing state for each button

void setup() {
  Serial.begin(57600);
  //  while (!Serial) {}

  trellis.begin();
  trellis.setBrightness(255);
  trellis.fill(0);
}


void loop() {
  unsigned long startTime = millis();

  if (Serial.available() >= BUTTON_DATA_LENGTH) {
    parseData();
  }

  //send press events to Live via serial
  trellis.tick();
  while (trellis.available()) {
    keypadEvent e = trellis.read();
    uint8_t i = e.bit.KEY;
    if (e.bit.EVENT == KEY_JUST_PRESSED) {
      pressed[i] = true;
      Serial.write(i);
    }
    else if (e.bit.EVENT == KEY_JUST_RELEASED) {
      pressed[i] = false;
    }
  }

  if ((startTime - lastPulseTime) >= PULSE_DURATION) {

    //flash any clip which is playing
    if (pulseOn) {
      for (uint8_t i = 0; i < N_BUTTONS; i++) {
          setPixelWithColorsIndex(i, false);
      }
    }
    else {
      for (uint8_t i = 0; i < N_BUTTONS; i++) {
        if (playing[i]) {
          setPixelWithColorsIndex(i, true);
        }
        else setPixelWithColorsIndex(i, false);
      }
    }
    pulseOn = !pulseOn;
    lastPulseTime = millis();
  }
}

void parseData() {

  //check for ! start char
  if (Serial.read() == '!') {
    uint8_t id = Serial.read();

    //check for Color data
    if (id == 'C') {
      for (int i = 0; i < 96; i++) {
        colors[i] = Serial.read();
      }

      //color button leds
      for (int i = 0; i < N_BUTTONS; i++) {
        setPixelWithColorsIndex(i, false);
      }
    }

    //check for clip status data
    else if (id == 'B') {
      uint8_t x = Serial.read();
      uint8_t state = Serial.read();
      uint8_t y = Serial.read();

      if (state == 0) { //if state is 0, all clips in track are stopped
        for (int i = 0; i < HEIGHT; i++) {
          uint8_t index = i * WIDTH + x;
          playing[index] = state;
        }
      }

      else {  //all other clips in track should stop
        for (int i = 0; i < HEIGHT; i++) {
          uint8_t index = i * WIDTH + x;
          playing[index] = 0;
        }
        //save playing state
        uint8_t index = y * WIDTH + x;
        playing[index] = state;
      }
    }
  }
}

void setPixelWithColorsIndex(int i, bool dimmed) {

  uint8_t red = colors[i * 3];
  uint8_t green = colors[i * 3 + 1];
  uint8_t blue = colors[i * 3 + 2];
  if (dimmed) {
    setPixelWithGamma(i, red / 2, green / 2, blue / 2);
  }
  else {
    setPixelWithGamma(i, red, green, blue);
  }

}

void setPixelWithGamma(int pixelNumber, uint8_t red, uint8_t green, uint8_t blue) {

  uint32_t color = trellis.Color(
                     pgm_read_byte(&gamma8[red]),
                     pgm_read_byte(&gamma8[green]),
                     pgm_read_byte(&gamma8[blue]));

  trellis.setPixelColor(pixelNumber, color);
}

const uint8_t PROGMEM gamma8[] = {
  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  1,  1,
  1,  1,  1,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  2,  2,  2,
  2,  3,  3,  3,  3,  3,  3,  3,  4,  4,  4,  4,  4,  5,  5,  5,
  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  9,  9,  9, 10,
  10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16,
  17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 24, 24, 25,
  25, 26, 27, 27, 28, 29, 29, 30, 31, 32, 32, 33, 34, 35, 35, 36,
  37, 38, 39, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 50,
  51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68,
  69, 70, 72, 73, 74, 75, 77, 78, 79, 81, 82, 83, 85, 86, 87, 89,
  90, 92, 93, 95, 96, 98, 99, 101, 102, 104, 105, 107, 109, 110, 112, 114,
  115, 117, 119, 120, 122, 124, 126, 127, 129, 131, 133, 135, 137, 138, 140, 142,
  144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 167, 169, 171, 173, 175,
  177, 180, 182, 184, 186, 189, 191, 193, 196, 198, 200, 203, 205, 208, 210, 213,
  215, 218, 220, 223, 225, 228, 231, 233, 236, 239, 241, 244, 247, 249, 252, 255
};

Upload the code

Now, just a few more steps in the Arduino IDE and you'll have the NeoTrellis ready for communication with Ableton Live:

  1. Reset your NeoTrellis by double-clicking the recessed reset button on the back. NeoTrellis is ready to be programmed when the rear LED turns green.
  2. Go to Tools -> Board and select Adafruit Trellis M4 (SAMD51) from the list.
  3. Go to Tools -> Port and select the port which name contains Adafruit Trellis M4 in the name.
  4. Upload the sketch by clicking Sketch -> Upload.
This guide was first published on Dec 27, 2018. It was last updated on Dec 27, 2018. This page (NeoTrellis Setup) was last updated on Oct 21, 2019.