Published July 27, 2020 © CC BY-NC-SA

So I Fixed a Broken Hasbro Lightsaber

Refit a 2004 Hasbro lightsaber toy with Arduino Nano, NeoPixel, ADXL335 and a DFPlayer Mini.

IntermediateShowcase (no instructions)7,054

Things used in this project

Hardware components

Arduino Nano R3

Adafruit NeoPixel Ring: WS2812 5050 RGB LED

DFRobot DFPlayer - A Mini MP3 Player

Adafruit Analog Accelerometer: ADXL335

Software apps and online services

Arduino IDE

Story

A while ago I was sorting some old Star Wars toys that my brothers and I got during SW fan years (before and during the prequel trilogy). I found this 2004 lightsaber in a box and load batteries in it. Nope - it was broken. Sad.

I thought about throwing it away, then I got an idea.

Since this lightsaber is a "color changing" version, the blade is white (or transparent). You can make it light up as any kind of colors with RGB LEDs. So I tear it open, break down some inner wall structures and put it various components:

Arduino Nano
9 NeoPixel (WS2812b) LEDs (8 in a ring and an additional one in the center - I linked them together)
ADXL335 3-axis acceleration analog sensor
DFPlayer Mini MP3 Player (see docs)

I downloaded a bunch of lightsaber sound effects and put them into a mini SD card in the MP3 player. I added a few movie quotes and soundtrack music as well.

Also, two parts in the lightsaber are kept as part of the system (I cut and soldered their wires to jumper wires):

The side button
The speaker

As it happens, a small 5V power bank (which I used for my first project here) can be fitted into the original battery compartment.

I use jumper wires since I wasn't sure if these will work or fit.

Arduino Nano with the ADXL335 clued at the side of the mini breadboard

The DFPlayer mini, the speaker (under the wires) and the side button

Right now the saber functions as follows:

When you press the side button, the saber would "activate" with a random activation sound and a random color (red, green, blue, yellow, cyan, purple, white).
Play a random humming sound.
When the saber is activated, pressing the button and release quickly would shut it down (also playing a random shut down sound).
However, if you press the button a bit longer or long enough, it would play a random movie quote or soundtrack music,
While playing a quote or music, pressing it again quickly would return it to the humming mode.
While in humming mode, moving the saber fast enough would make it play a random whooshing sound.

I decided not to put in clashing sounds and the corresponding motion detection, since it would be tricky to detect different motions, and I don't want to smash this thing around and break it again.

I also don't want to use rainbow colors...it's meaningless here and the effect looks less effective in the plastic tube.

Probably someday I'll make it a Spaceball parody version, just maybe.

Refitted Hasbro lightsaber

#include "Arduino.h"
#include "SoftwareSerial.h"
#include "DFRobotDFPlayerMini.h" // https://github.com/DFRobot/DFRobotDFPlayerMini
#include <Adafruit_NeoPixel.h> // https://github.com/adafruit/Adafruit_NeoPixel
#include "ADXL335.h" // https://github.com/Seeed-Studio/Accelerometer_ADXL335

#define BUTTON_PIN 2
#define NEOPIXEL_PIN 3
#define MP3_BUSY_PIN 4
#define MP3_RX_PIN 5
#define MP3_TX_PIN 6

#define ACCEL_TRIGGER_RATIO 0.06

#define NEOPIXEL_NUM 9
#define BUTTON_LONGPRESS_1 750
#define BUTTON_LONGPRESS_2 1500

#define SABER_ON 1
#define SABER_HUM 2
#define SABER_MOVE 3
#define SABER_OFF 4
#define SABER_QUOTE 5
#define SABER_MUSIC 6

#define SABER_ON_START 1
#define SABER_ON_END 15
#define SABER_HUM_START 16
#define SABER_HUM_END 25
#define SABER_MOVE_START 26
#define SABER_MOVE_END 50
#define SABER_OFF_START 51
#define SABER_OFF_END 58
#define SABER_QUOTE_START 59
#define SABER_QUOTE_END 72
#define SABER_MUSIC_START 73
#define SABER_MUSIC_END 81

#define SABER_ON_VOLUME 25
#define SABER_HUM_VOLUME 20
#define SABER_MOVE_VOLUME 22
#define SABER_OFF_VOLUME 25
#define SABER_QUOTE_VOLUME 20
#define SABER_MUSIC_VOLUME 22

SoftwareSerial softSerial(MP3_RX_PIN, MP3_TX_PIN);
DFRobotDFPlayerMini mp3;

ADXL335 accel;
int x, y, z, button_start, button_end, hum_index;
float last_accel_data, current_accel_data, accel_diff;
bool r, g, b, musicMode;

Adafruit_NeoPixel leds(NEOPIXEL_NUM, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);

void setup() {

  Serial.begin(9600);
  softSerial.begin(9600);

  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(MP3_BUSY_PIN, INPUT_PULLUP);

  leds.begin();
  accel.begin();

  mp3.begin(softSerial);
  delay(50);
  mp3.EQ(DFPLAYER_EQ_ROCK);
  musicMode = false;
  delay(200);

  clearLEDs();

}

void loop() {

  randomSeed(analogRead(A5) + analogRead(A6) + analogRead(A7));

  while (!buttonPressed());
  clearLEDs();
  chooseRGB();
  playMp3(SABER_ON);
  delay(50);
  for (int i = 0; i < 255; i++) {
    setLEDs(r * i, g * i, b * i);
    delay(1);
  }
  while (mp3IsBusy());
  while (buttonPressed());
  delay(200);
  chooseHum();
  getAccel();

  while (true) {

    last_accel_data = current_accel_data;
    getAccel();
    accel_diff = (current_accel_data - last_accel_data) / last_accel_data;

    if (!mp3IsBusy()) {
      musicMode = false;
      loopHum();
    }

    if (!musicMode && accel_diff >= ACCEL_TRIGGER_RATIO) {
      playMp3(SABER_MOVE);
      while (!mp3IsBusy());
      while (mp3IsBusy());
      delay(200);
    }

    if (buttonPressed()) {
      button_start = millis();
      while (buttonPressed());
      button_end = millis();
      if (button_end - button_start >= BUTTON_LONGPRESS_2) {
        musicMode = true;
        playMp3(SABER_MUSIC);
      } else if (button_end - button_start >= BUTTON_LONGPRESS_1) {
        musicMode = true;
        playMp3(SABER_QUOTE);
      } else {
        if (musicMode) {
          musicMode = false;
          mp3.pause();
          delay(200);
        } else {
          break;
        }
      }
    }
    delay(50);
  }

  delay(50);
  playMp3(SABER_OFF);
  delay(150);
  for (int i = 255; i >= 0; i--) {
    setLEDs(r * i, g * i, b * i);
    delay(2);
  }
  while (mp3IsBusy());
  while (!buttonPressed());
  delay(200);

}

bool buttonPressed() {
  return !digitalRead(BUTTON_PIN);
}

bool mp3IsBusy() {
  return !digitalRead(MP3_BUSY_PIN);
}

void playMp3(int soundType) {
  int startIndex, endIndex, selectedVolume;
  switch (soundType) {
    case SABER_ON:
      startIndex = SABER_ON_START;
      endIndex = SABER_ON_END;
      selectedVolume = SABER_ON_VOLUME;
      break;
    case SABER_HUM:
      startIndex = SABER_HUM_START;
      endIndex = SABER_HUM_END;
      selectedVolume = SABER_HUM_VOLUME;
      break;
    case SABER_MOVE:
      startIndex = SABER_MOVE_START;
      endIndex = SABER_MOVE_END;
      selectedVolume = SABER_MOVE_VOLUME;
      break;
    case SABER_OFF:
      startIndex = SABER_OFF_START;
      endIndex = SABER_OFF_END;
      selectedVolume = SABER_OFF_VOLUME;
      break;
    case SABER_QUOTE:
      startIndex = SABER_QUOTE_START;
      endIndex = SABER_QUOTE_END;
      selectedVolume = SABER_QUOTE_VOLUME;
      break;
    case SABER_MUSIC:
      startIndex = SABER_MUSIC_START;
      endIndex = SABER_MUSIC_END;
      selectedVolume = SABER_MUSIC_VOLUME;
      break;
    default:
      startIndex = 0;
      endIndex = 0;
      selectedVolume = SABER_HUM_VOLUME;
  }
  mp3.volume(selectedVolume);
  delay(50);
  mp3.play(random(startIndex, endIndex + 1));
  delay(200);
}

void chooseHum() {
  hum_index = random(SABER_HUM_START, SABER_HUM_END + 1);
}

void loopHum() {
  mp3.volume(SABER_HUM_VOLUME);
  delay(50);
  mp3.play(hum_index);
  delay(200);
}

void chooseRGB() {
  r = random(0, 2);
  g = random(0, 2);
  b = (r || g) ? random(0, 2) : true;
}

void clearLEDs() {
  leds.clear();
  leds.show();
}

void setLEDs(int rc, int gc, int bc) {
  for (int i = 0; i < NEOPIXEL_NUM; i++) {
    leds.setPixelColor(i, leds.Color(rc, gc, bc));
  }
  leds.show();
}

void getAccel() {
  accel.getXYZ(&x, &y, &z);
  current_accel_data = x + y + z;
}