I've been wanting an Arduino microcontroller for some time and last week I finally broke down and bought one. I've been dicking around with some simple projects, but on of the things that I've been eagerly looking forward to doing is a computer controlled Christmas lights setup. There are some selfish reasons, I'll admit, like winning the company Christmas decorations contest. But, I digress.

To that end, I horked some code from a Taiko no Tatsujin clone I'd been writing a few years ago and tossed the output at the Arduino via serial data. Here's the result:

Code is after the break!

The sketch for this is stupid simple: take the number from serial, make that pin high. Wait a bit, turn it off. Rinse and repeat.

int rxPin = 0;

void setup() {
  Serial.begin(9600); 
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
}

void loop() {
  if (Serial.available() > 0) {
    rxPin = Serial.read();
    digitalWrite(rxPin + 8, HIGH);
    delay(10);
    digitalWrite(rxPin + 8, LOW);
  }
}

All the magic happens in the C# application that funnels the data down to the Arduino. It reads the beatmap (a custom XML format with data scraped from an osu! beatmap) and times the whole thing out.

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO.Ports;
using System.Xml;
using System.Media;

using WMPLib;

namespace ArduinoTalk
{
    class Program
    {

        private class Note
        {
            public int x, type, accuracy;
            public bool active, deployed, hasBeenClosest, closest;
            public long delay;
        }

        // Constants
        private const int EASY = 0;
        private const int NORMAL = 1;
        private const int HARD = 2;
        private const int ONI = 3;
        private const int DON = 0;
        private const int KA = 1;

        private static List<Note> notes = new List<Note>();
        private static string songTitle, songFile;
        private static int bpm, noteSpeed, noteOffset, frameRate, currentNote;
        private static string[] maps = new string[4];
        private static WindowsMediaPlayer player = new WindowsMediaPlayer();
        private static int lastNote = 0;
        private static int prevNote = 0;
        private static int noteRun = 0;

        static void Main(string[] args)
        {

            SerialPort port = new SerialPort("COM5");
            port.Open();
            if (port.IsOpen)
            {
                loadSong("taiko_march");
                port.BaudRate = 9600;
                beginSong(HARD);

                System.Threading.Thread.Sleep(100);

                while (player.controls.currentPosition < player.currentMedia.duration)
                {
                    double positionMilli = Math.Round(player.controls.currentPosition * 1000);
                    if (lastNote < notes.Count && notes[lastNote].delay - positionMilli <= 0)
                    {
                        noteRun = prevNote == notes[lastNote].type ? noteRun + 1 : 0;
                        int type = notes[lastNote].type * 2;
                        type = prevNote == notes[lastNote].type ? type + noteRun % 2 : type;
                        byte[] data = new byte[] { Convert.ToByte(type) };
                        port.Write(data, 0, 1);
                        Console.WriteLine("{0}, {1}, {2}", notes[lastNote].type, type, noteRun);
                        prevNote = notes[lastNote].type;
                        lastNote++;
                    }
                }
                

            }
        }

        private static void loadSong(string patternFile)
        {

            XmlDocument xmlDoc = new XmlDocument();

            // Load and parse the song file
            xmlDoc.Load("maps/" + patternFile + ".xml");
            foreach (XmlNode node in xmlDoc.FirstChild)
            {
                switch (node.Name)
                {
                    case "title":
                        songTitle = node.FirstChild.Value;
                        break;
                    case "bpm":
                        bpm = Convert.ToInt32(node.FirstChild.Value);
                        break;
                    case "file":
                        songFile = node.FirstChild.Value;
                        break;
                    case "maps":
                        foreach (XmlNode xmlMap in node.ChildNodes)
                        {
                            switch (xmlMap.Name)
                            {
                                case "easy":
                                    maps[EASY] = xmlMap.FirstChild.Value;
                                    break;
                                case "normal":
                                    maps[NORMAL] = xmlMap.FirstChild.Value;
                                    break;
                                case "hard":
                                    maps[HARD] = xmlMap.FirstChild.Value;
                                    break;
                                case "oni":
                                    maps[ONI] = xmlMap.FirstChild.Value;
                                    break;
                            }
                        }
                        break;
                }
            }

        }

        public static void beginSong(int difficulty)
        {

            // Load the map
            string[] map = maps[difficulty].Split(',');
            notes.Clear();
            foreach (string note in map)
            {
                Note t = new Note();
                string type = note.Substring(0, 1);
                t.delay = Convert.ToInt32(note.Substring(1, note.Length - 1));
                switch (type)
                {
                    case "d":
                        t.type = DON;
                        break;
                    case "k":
                        t.type = KA;
                        break;
                }
                t.x = 852;
                notes.Add(t);
            }
            currentNote = 0;
            notes.Sort((x, y) => x.delay.CompareTo(y.delay));

            // Play the song and note the start time
            player.URL = "C:\\Users\\Matt\\Documents\\Visual~1\\Projects\\ArduinoTalk\\ArduinoTalk\\bin\\Debug\\maps\\" + songFile;
            player.controls.play();

        }

    }

}