memoryleak
Published © MIT

Visualize sorting algorithms with Arduino and LED strip

Feel confused about sorting algorithms? Use LEDs and Arduino to get better understanding about them!

BeginnerFull instructions provided1 hour2

Things used in this project

Hardware components

Seeeduino V4.2
Seeeduino V4.2
×1
Base Shield V2
Seeed Base Shield V2
×1
Waterproof WS2813 RGB LED Strip Waterproof
Seeed Waterproof WS2813 RGB LED Strip Waterproof
×1

Software apps and online services

Arduino IDE
Arduino IDE

Story

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Schematics

Hardware Schematic

Remember to connect your led strip to the right digital pin!

Code

Bubble sort

Arduino
Remember to set digital pin number and number of leds correctly
#include <FastLED.h>

#include "SparkFunLSM6DS3.h"
#include "Wire.h"
#include "math.h"

// Which pin on the Arduino is connected to the NeoLEDS?
#define NUM_LEDS 30
#define DATA_PIN 6
CRGB leds[NUM_LEDS];

int r, g, b;


void setup() {
  Serial.begin(9600);
  FastLED.addLeds<WS2812, DATA_PIN, RGB>(leds, NUM_LEDS);
  FastLED.setBrightness(100); //init led strip 
}

void loop() {
  bubbleSort(); //call bubbleSort function
  exit(0); //stop loop
}

void bubbleSort()
{ 
  int arr[NUM_LEDS]; //init an array with 30 elements
  for (int j = 0; j < NUM_LEDS; j++) 
  {
    int i = random(NUM_LEDS);
    arr[j] = i;
    setColor(i, j);
  }
  /* 
  give every led a randnom number between (0,30). The number will be used to generate a unique color to represent the value of the number
  */

  for (int m = 0; m < NUM_LEDS - 1; m++) {
    for (int n = 0; n < NUM_LEDS - 1 - m; n++) {
      if (arr[n] > arr[n + 1]) {
        setColor(arr[n + 1], n); // swap the larger number and smaller number
        setColor(arr[n], n + 1);
        int temp = arr[n + 1];
        arr[n + 1] = arr[n];
        arr[n] = temp;
      }
      // bubble sort algorithm
    }
  }
}
void setColor(int color, int led) { 
  // use an int number between (0,30) to determine the color of the specified led 
  if (color < NUM_LEDS / 3) {
    r = 255;
    g = floor(250 * 3 * color / NUM_LEDS);
    b = 0;
  } else if (color < NUM_LEDS / 2) {
    r = floor(750 - color * (250 * 6 / NUM_LEDS));
    g = 255;
    b = 0;
  } else if (color < NUM_LEDS * 2 / 3) {
    r = 0;
    g = 255;
    b = floor(color * (250 * 6 / NUM_LEDS) - 750);
  } else if (color < NUM_LEDS * 5 / 6) {
    r = 0;
    g = floor(1250 - color * (250 * 6 / NUM_LEDS));
    b = 255;
  } else {
    r = floor(150 * color * (6 / NUM_LEDS) - 750);
    g = 0;
    b = 255;
  } 
  leds[led].setRGB(g, r, b);
  FastLED.show(); // This sends the updated piaXel color to the hardware.
  delay(30);
}

Quick sort

Arduino
Remember to set the data pin and number of leds correctly
#include <FastLED.h>

#include "SparkFunLSM6DS3.h"
#include "Wire.h"
#include "math.h"

// Which pin on the Arduino is connected to the NeoLEDS?
// On a Trinket or Gemma we suggest changing this to 1
#define NUM_LEDS 30
#define DATA_PIN 6
CRGB leds[NUM_LEDS];

int r, g, b;

void setup()
{
  Serial.begin(9600);
  FastLED.addLeds<WS2812, DATA_PIN, RGB>(leds, NUM_LEDS);
  FastLED.setBrightness(100); //init the led strip with 100 brightness
}

void loop()
{
  int arr[NUM_LEDS];
  for (int j = 0; j < NUM_LEDS; j++)
  {
    int i = random(NUM_LEDS);
    arr[j] = i;
    setColor(i, j);
  } //set the led strip with 30 random unique color representing different values
  quickSort(arr, 0, 29); // call quicksort function
      exit(0);
}

void quickSort(int num[], int l, int r)
{
  if (l >= r) 
    return;
  int m = l, n = r, x = num[l];
  while (m < n)
  {
    while (m < n && num[n] >= x) 
      n--;
    if (m < n)
    {
      setColor(num[n], m);
      num[m++] = num[n]; 
    }

    while (m < n && num[m] <= x) 
      m++;
    if (m < n)
    {
      setColor(num[m], n);
      num[n--] = num[m];
    }
  }
  num[m] = x;               //put the inital x into m element
  setColor(x, m);
  quickSort(num, l, m - 1); //use m as mid value, use recursive call
  quickSort(num, m + 1, r);
}
void setColor(int color, int led)
{
  if (color < NUM_LEDS / 3)
  {
    r = 255;
    g = floor(250 * 3 * color / NUM_LEDS);
    b = 0;
  }
  else if (color < NUM_LEDS / 2)
  {
    r = floor(750 - color * (250 * 6 / NUM_LEDS));
    g = 255;
    b = 0;
  }
  else if (color < NUM_LEDS * 2 / 3)
  {
    r = 0;
    g = 255;
    b = floor(color * (250 * 6 / NUM_LEDS) - 750);
  }
  else if (color < NUM_LEDS * 5 / 6)
  {
    r = 0;
    g = floor(1250 - color * (250 * 6 / NUM_LEDS));
    b = 255;
  }
  else
  {
    r = floor(150 * color * (6 / NUM_LEDS) - 750);
    g = 0;
    b = 255;
  }
  // convert an int value to rgb array
  leds[led].setRGB(g, r, b);
  FastLED.show(); // This sends the updated piaXel color to the hardware.
  delay(30);
}

Credits

memoryleak

memoryleak

3 projects • 4 followers
A soft and hardware engineer motivated by interest and fun

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