Deutsch
English
Menu
Kits / Starter Kit: Weather Station / Projects / Show Statistics with Button Control / Using C# to show different Weather Statistics

Using C# to show different Weather Statistics

For this project we are assuming, that you have a C# development environment set up and that you have a rudimentary understanding of the C# language.

If you are totally new to C# itself you should start here. If you are new to the Tinkerforge API, you should start here.

Goals

The LCD Bricklet is equipped with four buttons which should be used in this project to switch between different weather statistics:

  • standard weather measurement,
  • 24h min/max/average,
  • 24h graph and
  • time and date.

This project is based on the Using C# to write to LCD 20x4 Bricklet project. In the following we will show step-by-step how the above mentioned functions can be implemented. We will describe the general concept, so the program can be easily understood.

Step 1: Retrieving data

The structure of the program is exactly the same as in the Display environment measurements on LCD project.

We get the data over callbacks with a 1s interval. But this time we just save the measurements:

static void IlluminanceCB(BrickletAmbientLight sender, int illuminance)
{
    latestIlluminance = illuminance/10.0;
}

static void HumidityCB(BrickletHumidity sender, int humidity)
{
    latestHumidity = humidity/10.0;
}

static void AirPressureCB(BrickletBarometer sender, int airPressure)
{
    latestAirPressure = airPressure/1000.0;

    int temperature = sender.GetChipTemperature();
    latestTemperature = temperature/100.0;
}

To use the latest measurements we start a 1s timer

Timer timer = new Timer(Update, null, TimeSpan.Zero, TimeSpan.FromSeconds(1));

and put the measurements in a queue so we can later analyze them:

static private void Update(object state)
{
    // The measurements are initialized with NaN
    if(Double.IsNaN(latestIlluminance) ||
       Double.IsNaN(latestHumidity) ||
       Double.IsNaN(latestAirPressure) ||
       Double.IsNaN(latestTemperature))
    {
        return;
    }

    illuminanceQueue.Enqueue(latestIlluminance);
    if(illuminanceQueue.Count > 60*60*24) // Save max one day worth of measurements
    {
        illuminanceQueue.Dequeue();
    }

    humidityQueue.Enqueue(latestHumidity);
    if(humidityQueue.Count > 60*60*24)
    {
        humidityQueue.Dequeue();
    }

    airPressureQueue.Enqueue(latestAirPressure);
    if(airPressureQueue.Count > 60*60*24)
    {
        airPressureQueue.Dequeue();
    }

    temperatureQueue.Enqueue(latestTemperature);
    if(temperatureQueue.Count > 60*60*24)
    {
        temperatureQueue.Dequeue();
    }

    UpdateSwitch();
}

At a first glance this approach seems convoluted. Why can't we just call the Getter methods in the Update function or put the measurements in the queue during the callbacks?

There are two reasons why the utilized approach makes sense:

  1. The callbacks only get called in 1s intervals if the actual callback value changed. That means, if a measurement doesn't change for 10s, the callback will only be triggered after this 10s. This is good since it saves bandwidth, but we want to have a measurement every second, so we can use the data for statistics.
  2. By using callbacks with a 1s interval and a separate timer with a 1s interval, we can easily overcome short connection losses or similar. For example: If the Weather Station is controlled over Wi-Fi and the Wi-Fi connection is lost for 30s, we will just use the latest value that was retrieved for these 30s. If we would be using Getters for this, we would have to handle a timeout for each of the measurements. Since the standard timeout time of 2.5s is longer then our 1s interval, a timeout would actually distort the measurements.

Step 2: Button Control

For the button control, we have to add the ButtonPressed callback during the initialization:

brickletLCD.ButtonPressed += PressedCB;

In the callback we save the actual button that was pressed and we also increase a counter for the specific button, if the same button was pressed before. This allows us to cycle between different views in a specific mode (e.g. 24h graph).

private static byte buttonPressed = 0;
private static int[] buttonPressedCounter = {0, 0, 0, 0};

// [...]

static void PressedCB(BrickletLCD20x4 sender, byte button)
{
    if(button == buttonPressed)
    {
        buttonPressedCounter[button]++;
    }
    else
    {
        buttonPressed = button;
    }

    brickletLCD.ClearDisplay();
    UpdateSwitch();
}

To give instant feedback, we directly clear the display and call UpdateSwitch.

The UpdateSwitch method switches between the four different modes:

static private void UpdateSwitch()
{
    switch(buttonPressed)
    {
        case UPDATE_TYPE_STANDARD: UpdateStandard(); break;
        case UPDATE_TYPE_GRAPH: UpdateGraph(); break;
        case UPDATE_TYPE_MIN_MAX_AVG: UpdateMinMaxAvg(); break;
        case UPDATE_TYPE_TIME: UpdateTime(); break;
    }
}

The four modes are:

  • Standard: Displays all 4 measurements.
  • Graph: Displays a 24h graph of one measurement. It is possible to cycle through the different measurements with repeated presses of the button.
  • MinMaxAvg: Displays the minimum, maximum and average values of a measurement. It is also possible to cycle through the different measurements with repeated presses of the button.
  • Time: Displays current time and date.

Step 3: Show four modes on display

The implementation of the four modes:

Standard Mode

In standard mode we just show the measurements:

static private void UpdateStandard()
{
    string text = string.Format("Illuminanc {0,6:###.00} lx", latestIlluminance);
    brickletLCD.WriteLine(0, 0, text);

    text = string.Format("Humidity   {0,6:###.00} %", latestHumidity);
    brickletLCD.WriteLine(1, 0, text);

    text = string.Format("Air Press {0,7:####.00} mb", latestAirPressure);
    brickletLCD.WriteLine(2, 0, text);

    text = string.Format("Temperature {0,5:##.00} {1}C", latestTemperature, (char)0xDF);
    brickletLCD.WriteLine(3, 0, text);
}
Standard Mode

Graph Mode

In graph mode we show a bar graph of the last 24 hours:

static private void UpdateGraph()
{
    double barSumMin;
    double barSumMax;

    switch(buttonPressedCounter[1] % 4)
    {
        case MODE_ILLUMINANCE:
            UpdateGraphWriteBars(illuminanceQueue, out barSumMin, out barSumMax);
            UpdateGraphWriteTitle("I: ", barSumMin, barSumMax, illuminanceQueue.Count);
            break;

        case MODE_HUMIDITY:
            UpdateGraphWriteBars(humidityQueue, out barSumMin, out barSumMax);
            UpdateGraphWriteTitle("H: ", barSumMin, barSumMax, humidityQueue.Count);
            break;

        case MODE_AIR_PRESSURE:
            UpdateGraphWriteBars(airPressureQueue, out barSumMin, out barSumMax);
            UpdateGraphWriteTitle("A: ", barSumMin, barSumMax, airPressureQueue.Count);
            break;

        case MODE_TEMPERATURE:
            UpdateGraphWriteBars(temperatureQueue, out barSumMin, out barSumMax);
            UpdateGraphWriteTitle("T: ", barSumMin, barSumMax, temperatureQueue.Count);
            break;
    }
}

We don't go into detail here. The exact method how the bars are calculated can be seen in the final program. For the bar graph we have to configure some custom characters during the initialization:

static private void ConfigureCustomChars(BrickletLCD20x4 lcd)
{
    byte[][] c = new byte[8][];
    c[0] = new byte[8] {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff};
    c[1] = new byte[8] {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff};
    c[2] = new byte[8] {0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff};
    c[3] = new byte[8] {0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff};
    c[4] = new byte[8] {0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff};
    c[5] = new byte[8] {0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
    c[6] = new byte[8] {0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
    c[7] = new byte[8] {0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

    for(byte i = 0; i < c.Length; i++)
    {
        lcd.SetCustomCharacter(i, c[i]);
    }
}

This configures the eight available custom characters to bars with height one to eight.

Graph Mode

MinMaxAvg Mode

In MinMaxAvg mode we show minimum, maximum and average values of the last 24 hours:

static private void UpdateMinMaxAvg()
{
    switch(buttonPressedCounter[2] % 4)
    {
        case MODE_ILLUMINANCE:
            UpdateMinMaxAvgWrite("Illuminance    " + TimeFromSeconds(illuminanceQueue.Count),
                                 "Lux",
                                 GetMinMaxAvg(illuminanceQueue));
            break;

        case MODE_HUMIDITY:
            UpdateMinMaxAvgWrite("Humidity       " + TimeFromSeconds(humidityQueue.Count),
                                 "%RH",
                                 GetMinMaxAvg(humidityQueue));
            break;

        case MODE_AIR_PRESSURE:
            UpdateMinMaxAvgWrite("Air Pressure   " + TimeFromSeconds(airPressureQueue.Count),
                                 "hPa",
                                 GetMinMaxAvg(airPressureQueue));
            break;

        case MODE_TEMPERATURE:
            UpdateMinMaxAvgWrite("Temperature    " + TimeFromSeconds(temperatureQueue.Count),
                                 ((char)0xDF) + "C",
                                 GetMinMaxAvg(temperatureQueue));
            break;
    }
}

The values are written in 4 lines, whereby the first line is a title that shows the names of the measurements:

static private void UpdateMinMaxAvgWrite(string title, string unit, double[] values)
{
    String min = string.Format("Min: {0,2:##.00} {1}", values[0], unit);
    String max = string.Format("Max: {0,2:##.00} {1}", values[1], unit);
    String avg = string.Format("Avg: {0,2:##.00} {1}", values[2], unit);
    brickletLCD.WriteLine(0, 0, title);
    brickletLCD.WriteLine(1, 0, min);
    brickletLCD.WriteLine(2, 0, avg);
    brickletLCD.WriteLine(3, 0, max);
}
MinMaxAvg Mode

Time Mode

In time mode we show the current time and date:

static private void UpdateTime()
{
    string line0 = DateTime.Now.ToString("HH:MM:ss");
    string line1 = DateTime.Now.ToString("dddd");
    string line2 = DateTime.Now.ToString("D");
    brickletLCD.WriteLine((byte)0, (byte)((LINE_LENGTH-line0.Length)/2), line0);
    brickletLCD.WriteLine((byte)1, (byte)((LINE_LENGTH-line1.Length)/2), UTF16ToKS0066U(line1));
    brickletLCD.WriteLine((byte)2, (byte)((LINE_LENGTH-line2.Length)/2), UTF16ToKS0066U(line2));
}

The UTF16ToKS0066U method encodes umlauts to the LCD charset (ä, ö, ü, etc). This is needed, since C# gives the dates in the current operating system language.

Time Mode

Step 4: Everything put together

That's it! Now we have a Weather Station with four different modes that can be controlled with the LCD 20x4 Bricklet buttons.

This is of course still very elementary. There is lots of room for improvement. For example it would be possible to show the unit in graph mode whenever the shown values are not too big. Or perhaps it would be better to show the top and bottom values of the graph on the left side of the graph instead of the top.

All of the above put together (download):

using Tinkerforge;
using System;
using System.Collections;
using System.Threading;

class WeatherStation
{
    private static string HOST = "localhost";
    private static int PORT = 4223;

    private const byte UPDATE_TYPE_STANDARD = 0;
    private const byte UPDATE_TYPE_GRAPH = 1;
    private const byte UPDATE_TYPE_MIN_MAX_AVG = 2;
    private const byte UPDATE_TYPE_TIME = 3;

    private const int LINE_LENGTH = 20;
    private const int CUSTOM_CHAR_START = 8;
    private const int CUSTOM_CHAR_END = 15;
    private const int BAR_HEIGHT = 24;

    private const int MODE_ILLUMINANCE = 0;
    private const int MODE_HUMIDITY = 1;
    private const int MODE_AIR_PRESSURE = 2;
    private const int MODE_TEMPERATURE = 3;

    private static IPConnection ipcon = null;
    private static BrickletLCD20x4 brickletLCD = null;
    private static BrickletAmbientLight brickletAmbientLight = null;
    private static BrickletAmbientLightV2 brickletAmbientLightV2 = null;
    private static BrickletAmbientLightV3 brickletAmbientLightV3 = null;
    private static BrickletHumidity brickletHumidity = null;
    private static BrickletHumidityV2 brickletHumidityV2 = null;
    private static BrickletBarometer brickletBarometer = null;
    private static BrickletBarometerV2 brickletBarometerV2 = null;

    private static double latestIlluminance = Double.NaN;
    private static double latestHumidity = Double.NaN;
    private static double latestAirPressure = Double.NaN;
    private static double latestTemperature = Double.NaN;

    private static Queue illuminanceQueue = new Queue();
    private static Queue humidityQueue = new Queue();
    private static Queue airPressureQueue = new Queue();
    private static Queue temperatureQueue = new Queue();

    private static byte buttonPressed = 0;
    private static int[] buttonPressedCounter = {0, 0, 0, 0};

    private static Timer timer;

    static void IlluminanceCB(BrickletAmbientLight sender, int illuminance)
    {
        latestIlluminance = illuminance/10.0;
    }

    static void IlluminanceV2CB(BrickletAmbientLightV2 sender, long illuminance)
    {
        latestIlluminance = illuminance/100.0;
    }

    static void IlluminanceV3CB(BrickletAmbientLightV3 sender, long illuminance)
    {
        latestIlluminance = illuminance/100.0;
    }

    static void HumidityCB(BrickletHumidity sender, int humidity)
    {
        latestHumidity = humidity/10.0;
    }

    static void HumidityV2CB(BrickletHumidityV2 sender, int humidity)
    {
        latestHumidity = humidity/100.0;
    }

    static void AirPressureCB(BrickletBarometer sender, int airPressure)
    {
        latestAirPressure = airPressure/1000.0;

        int temperature = sender.GetChipTemperature();
        latestTemperature = temperature/100.0;
    }

    static void AirPressureV2CB(BrickletBarometerV2 sender, int airPressure)
    {
        latestAirPressure = airPressure/1000.0;

        int temperature = sender.GetTemperature();
        latestTemperature = temperature/100.0;
    }

    static void PressedCB(BrickletLCD20x4 sender, byte button)
    {
        if(button == buttonPressed)
        {
            buttonPressedCounter[button]++;
        }
        else
        {
            buttonPressed = button;
        }

        brickletLCD.ClearDisplay();
        UpdateSwitch();
    }

    static void EnumerateCB(object sender, string UID, string connectedUID, char position,
                            short[] hardwareVersion, short[] firmwareVersion,
                            int deviceIdentifier, short enumerationType)
    {
        if(enumerationType == IPConnection.ENUMERATION_TYPE_CONNECTED ||
           enumerationType == IPConnection.ENUMERATION_TYPE_AVAILABLE)
        {
            if(deviceIdentifier == BrickletLCD20x4.DEVICE_IDENTIFIER)
            {
                try
                {
                    brickletLCD = new BrickletLCD20x4(UID, ipcon);
                    brickletLCD.ClearDisplay();
                    brickletLCD.BacklightOn();
                    ConfigureCustomChars(brickletLCD);
                    brickletLCD.ButtonPressed += PressedCB;
                    System.Console.WriteLine("LCD 20x4 initialized");
                }
                catch(TinkerforgeException e)
                {
                    System.Console.WriteLine("LCD 20x4 init failed: " + e.Message);
                    brickletLCD = null;
                }
            }
            else if(deviceIdentifier == BrickletAmbientLight.DEVICE_IDENTIFIER)
            {
                try
                {
                    brickletAmbientLight = new BrickletAmbientLight(UID, ipcon);
                    brickletAmbientLight.SetIlluminanceCallbackPeriod(1000);
                    brickletAmbientLight.Illuminance += IlluminanceCB;
                    System.Console.WriteLine("Ambient Light initialized");
                }
                catch(TinkerforgeException e)
                {
                    System.Console.WriteLine("Ambient Light init failed: " + e.Message);
                    brickletAmbientLight = null;
                }
            }
            else if(deviceIdentifier == BrickletAmbientLightV2.DEVICE_IDENTIFIER)
            {
                try
                {
                    brickletAmbientLightV2 = new BrickletAmbientLightV2(UID, ipcon);
                    brickletAmbientLightV2.SetConfiguration(BrickletAmbientLightV2.ILLUMINANCE_RANGE_64000LUX,
                                                            BrickletAmbientLightV2.INTEGRATION_TIME_200MS);
                    brickletAmbientLightV2.SetIlluminanceCallbackPeriod(1000);
                    brickletAmbientLightV2.Illuminance += IlluminanceV2CB;
                    System.Console.WriteLine("Ambient Light 2.0 initialized");
                }
                catch(TinkerforgeException e)
                {
                    System.Console.WriteLine("Ambient Light 2.0 init failed: " + e.Message);
                    brickletAmbientLightV2 = null;
                }
            }
            else if(deviceIdentifier == BrickletAmbientLightV3.DEVICE_IDENTIFIER)
            {
                try
                {
                    brickletAmbientLightV3 = new BrickletAmbientLightV3(UID, ipcon);
                    brickletAmbientLightV3.SetConfiguration(BrickletAmbientLightV3.ILLUMINANCE_RANGE_64000LUX,
                                                            BrickletAmbientLightV3.INTEGRATION_TIME_200MS);
                    brickletAmbientLightV3.SetIlluminanceCallbackConfiguration(1000, false, 'x', 0, 0);
                    brickletAmbientLightV3.IlluminanceCallback += IlluminanceV3CB;
                    System.Console.WriteLine("Ambient Light 3.0 initialized");
                }
                catch(TinkerforgeException e)
                {
                    System.Console.WriteLine("Ambient Light 3.0 init failed: " + e.Message);
                    brickletAmbientLightV3 = null;
                }
            }
            else if(deviceIdentifier == BrickletHumidity.DEVICE_IDENTIFIER)
            {
                try
                {
                    brickletHumidity = new BrickletHumidity(UID, ipcon);
                    brickletHumidity.SetHumidityCallbackPeriod(1000);
                    brickletHumidity.Humidity += HumidityCB;
                    System.Console.WriteLine("Humidity initialized");
                }
                catch(TinkerforgeException e)
                {
                    System.Console.WriteLine("Humidity init failed: " + e.Message);
                    brickletHumidity = null;
                }
            }
            else if(deviceIdentifier == BrickletHumidityV2.DEVICE_IDENTIFIER)
            {
                try
                {
                    brickletHumidityV2 = new BrickletHumidityV2(UID, ipcon);
                    brickletHumidityV2.SetHumidityCallbackConfiguration(1000, true, 'x', 0, 0);
                    brickletHumidityV2.HumidityCallback += HumidityV2CB;
                    System.Console.WriteLine("Humidity 2.0 initialized");
                }
                catch(TinkerforgeException e)
                {
                    System.Console.WriteLine("Humidity 2.0 init failed: " + e.Message);
                    brickletHumidityV2 = null;
                }
            }
            else if(deviceIdentifier == BrickletBarometer.DEVICE_IDENTIFIER)
            {
                try
                {
                    brickletBarometer = new BrickletBarometer(UID, ipcon);
                    brickletBarometer.SetAirPressureCallbackPeriod(1000);
                    brickletBarometer.AirPressure += AirPressureCB;
                    System.Console.WriteLine("Barometer initialized");
                }
                catch(TinkerforgeException e)
                {
                    System.Console.WriteLine("Barometer init failed: " + e.Message);
                    brickletBarometer = null;
                }
            }
            else if(deviceIdentifier == BrickletBarometerV2.DEVICE_IDENTIFIER)
            {
                try
                {
                    brickletBarometerV2 = new BrickletBarometerV2(UID, ipcon);
                    brickletBarometerV2.SetAirPressureCallbackConfiguration(1000, false, 'x', 0, 0);
                    brickletBarometerV2.AirPressureCallback += AirPressureV2CB;
                    System.Console.WriteLine("Barometer 2.0 initialized");
                }
                catch(TinkerforgeException e)
                {
                    System.Console.WriteLine("Barometer 2.0 init failed: " + e.Message);
                    brickletBarometer = null;
                }
            }
        }
    }

    static void ConnectedCB(object sender, short connectedReason)
    {
        if(connectedReason == IPConnection.CONNECT_REASON_AUTO_RECONNECT)
        {
            System.Console.WriteLine("Auto Reconnect");

            while(true)
            {
                try
                {
                    ipcon.Enumerate();
                    break;
                }
                catch(NotConnectedException e)
                {
                    System.Console.WriteLine("Enumeration Error: " + e.Message);
                    System.Threading.Thread.Sleep(1000);
                }
            }
        }
    }

    static private void ConfigureCustomChars(BrickletLCD20x4 lcd)
    {
        byte[][] c = new byte[8][];
        c[0] = new byte[8] {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff};
        c[1] = new byte[8] {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff};
        c[2] = new byte[8] {0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff};
        c[3] = new byte[8] {0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff};
        c[4] = new byte[8] {0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff};
        c[5] = new byte[8] {0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
        c[6] = new byte[8] {0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
        c[7] = new byte[8] {0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

        for(byte i = 0; i < c.Length; i++)
        {
            lcd.SetCustomCharacter(i, c[i]);
        }
    }

    static private string TimeFromSeconds(int s)
    {
        string str = "(";
        int m = s/60;
        int h = m/60;

        if(h > 0)
        {
            str += h + "h)";
        }
        else
        {
            if(m == 0)
            {
                m = 1;
            }
            str += m + "m)";
        }

        if(str.Length == 4)
        {
            return " " + str;
        }

        return str;
    }

    // From http://www.tinkerforge.com/en/doc/Software/Bricklets/LCD20x4_Bricklet_CSharp.html#unicode
    // Maps a normal UTF-16 encoded string to the LCD charset
    static string UTF16ToKS0066U(string utf16)
    {
        string ks0066u = "";
        char c;

        for (int i = 0; i < utf16.Length; i++)
        {
            int codePoint = Char.ConvertToUtf32(utf16, i);

            if (Char.IsSurrogate(utf16, i))
            {
                // Skip low surrogate
                i++;
            }

            // ASCII subset from JIS X 0201
            if (codePoint >= 0x0020 && codePoint <= 0x007e)
            {
                // The LCD charset doesn't include '\' and '~', use similar characters instead
                switch (codePoint)
                {
                    case 0x005c: c = (char)0xa4; break; // REVERSE SOLIDUS maps to IDEOGRAPHIC COMMA
                    case 0x007e: c = (char)0x2d; break; // TILDE maps to HYPHEN-MINUS
                    default: c = (char)codePoint; break;
                }
            }
            // Katakana subset from JIS X 0201
            else if (codePoint >= 0xff61 && codePoint <= 0xff9f)
            {
                c = (char)(codePoint - 0xfec0);
            }
            // Special characters
            else
            {
                switch (codePoint)
                {
                    case 0x00a5: c = (char)0x5c; break; // YEN SIGN
                    case 0x2192: c = (char)0x7e; break; // RIGHTWARDS ARROW
                    case 0x2190: c = (char)0x7f; break; // LEFTWARDS ARROW
                    case 0x00b0: c = (char)0xdf; break; // DEGREE SIGN maps to KATAKANA SEMI-VOICED SOUND MARK
                    case 0x03b1: c = (char)0xe0; break; // GREEK SMALL LETTER ALPHA
                    case 0x00c4: c = (char)0xe1; break; // LATIN CAPITAL LETTER A WITH DIAERESIS
                    case 0x00e4: c = (char)0xe1; break; // LATIN SMALL LETTER A WITH DIAERESIS
                    case 0x00df: c = (char)0xe2; break; // LATIN SMALL LETTER SHARP S
                    case 0x03b5: c = (char)0xe3; break; // GREEK SMALL LETTER EPSILON
                    case 0x00b5: c = (char)0xe4; break; // MICRO SIGN
                    case 0x03bc: c = (char)0xe4; break; // GREEK SMALL LETTER MU
                    case 0x03c2: c = (char)0xe5; break; // GREEK SMALL LETTER FINAL SIGMA
                    case 0x03c1: c = (char)0xe6; break; // GREEK SMALL LETTER RHO
                    case 0x221a: c = (char)0xe8; break; // SQUARE ROOT
                    case 0x00b9: c = (char)0xe9; break; // SUPERSCRIPT ONE maps to SUPERSCRIPT (minus) ONE
                    case 0x00a4: c = (char)0xeb; break; // CURRENCY SIGN
                    case 0x00a2: c = (char)0xec; break; // CENT SIGN
                    case 0x2c60: c = (char)0xed; break; // LATIN CAPITAL LETTER L WITH DOUBLE BAR
                    case 0x00f1: c = (char)0xee; break; // LATIN SMALL LETTER N WITH TILDE
                    case 0x00d6: c = (char)0xef; break; // LATIN CAPITAL LETTER O WITH DIAERESIS
                    case 0x00f6: c = (char)0xef; break; // LATIN SMALL LETTER O WITH DIAERESIS
                    case 0x03f4: c = (char)0xf2; break; // GREEK CAPITAL THETA SYMBOL
                    case 0x221e: c = (char)0xf3; break; // INFINITY
                    case 0x03a9: c = (char)0xf4; break; // GREEK CAPITAL LETTER OMEGA
                    case 0x00dc: c = (char)0xf5; break; // LATIN CAPITAL LETTER U WITH DIAERESIS
                    case 0x00fc: c = (char)0xf5; break; // LATIN SMALL LETTER U WITH DIAERESIS
                    case 0x03a3: c = (char)0xf6; break; // GREEK CAPITAL LETTER SIGMA
                    case 0x03c0: c = (char)0xf7; break; // GREEK SMALL LETTER PI
                    case 0x0304: c = (char)0xf8; break; // COMBINING MACRON
                    case 0x00f7: c = (char)0xfd; break; // DIVISION SIGN

                    default:
                    case 0x25a0: c = (char)0xff; break; // BLACK SQUARE
                }
            }

            // Special handling for 'x' followed by COMBINING MACRON
            if (c == (char)0xf8)
            {
                if (!ks0066u.EndsWith("x"))
                {
                    c = (char)0xff; // BLACK SQUARE
                }

                if (ks0066u.Length > 0)
                {
                    ks0066u = ks0066u.Remove(ks0066u.Length - 1, 1);
                }
            }

            ks0066u += c;
        }

        return ks0066u;
    }

    static private double[] GetMinMaxAvg(Queue q)
    {
        if(q.Count == 0)
        {
            return new double[] {0.0, 0.0, 0.0};
        }

        double min = 10000.0;
        double max = -10000.0;
        double avg = 0.0;

        foreach(double v in q)
        {
            if(v < min)
            {
                min = v;
            }

            if(v > max)
            {
                max = v;
            }

            avg += v;
        }

        avg /= q.Count;

        return new double[] {min, max, avg};
    }

    static private void UpdateStandard()
    {
        string text = string.Format("Illumina {0,8:###.00} lx", latestIlluminance);
        brickletLCD.WriteLine(0, 0, text);

        text = string.Format("Humidity   {0,6:###.00} %", latestHumidity);
        brickletLCD.WriteLine(1, 0, text);

        text = string.Format("Air Press {0,7:####.00} mb", latestAirPressure);
        brickletLCD.WriteLine(2, 0, text);

        text = string.Format("Temperature {0,5:##.00} {1}C", latestTemperature, (char)0xDF);
        brickletLCD.WriteLine(3, 0, text);
    }

    static private void UpdateGraph()
    {
        double barSumMin;
        double barSumMax;

        switch(buttonPressedCounter[1] % 4)
        {
            case MODE_ILLUMINANCE:
                UpdateGraphWriteBars(illuminanceQueue, out barSumMin, out barSumMax);
                UpdateGraphWriteTitle("I: ", barSumMin, barSumMax, illuminanceQueue.Count);
                break;

            case MODE_HUMIDITY:
                UpdateGraphWriteBars(humidityQueue, out barSumMin, out barSumMax);
                UpdateGraphWriteTitle("H: ", barSumMin, barSumMax, humidityQueue.Count);
                break;

            case MODE_AIR_PRESSURE:
                UpdateGraphWriteBars(airPressureQueue, out barSumMin, out barSumMax);
                UpdateGraphWriteTitle("A: ", barSumMin, barSumMax, airPressureQueue.Count);
                break;

            case MODE_TEMPERATURE:
                UpdateGraphWriteBars(temperatureQueue, out barSumMin, out barSumMax);
                UpdateGraphWriteTitle("T: ", barSumMin, barSumMax, temperatureQueue.Count);
                break;
        }
    }

    static private void UpdateGraphWriteTitle(string s, double barSumMin, double barSumMax, int count)
    {
        string line0 = s + (int)barSumMin + " - " + (int)(barSumMax+1.0);
        string time = TimeFromSeconds(count);

        int numSpaces = LINE_LENGTH - line0.Length - time.Length;
        for(int i = 0; i < numSpaces; i++)
        {
            line0 += " ";
        }

        brickletLCD.WriteLine(0, 0, line0 + time);
    }

    static private void UpdateGraphWriteBars(Queue q, out double barSumMin, out double barSumMax)
    {
        barSumMin = 10000.0;
        barSumMax = -10000.0;

        int count = q.Count;

        int countBars = count/LINE_LENGTH;
        if(countBars == 0)
        {
            countBars = 1;
        }

        double[] barSum = {0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,
                           0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0};
        int i = 0;
        foreach(double v in q)
        {
            barSum[i/countBars] += v;
            i++;
            if(i == LINE_LENGTH*countBars)
            {
                break;
            }
        }

        for(i = 0; i < barSum.Length; i++)
        {
            barSum[i] /= countBars;
            if(barSum[i] < barSumMin)
            {
                barSumMin = barSum[i];
            }
            if(barSum[i] > barSumMax)
            {
                barSumMax = barSum[i];
            }
        }

        double scale = (BAR_HEIGHT-1)/(barSumMax - barSumMin);
        double offset = barSumMin * scale - 1;

        int[] barHeight = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
        for(i = 0; i < barSum.Length; i++)
        {
            barHeight[i] = (int)Math.Round(barSum[i] * scale - offset, 0);
        }

        char[][] lines = new char[4][];
        lines[1] = new char[LINE_LENGTH] {' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
                                          ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '};
        lines[2] = new char[LINE_LENGTH] {' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
                                          ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '};
        lines[3] = new char[LINE_LENGTH] {' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
                                          ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '};

        for(i = 0; i < barHeight.Length; i++)
        {
            int barLength = barHeight[i]/8;
            int j = 0;
            for(j = 0; j < barLength; j++)
            {
                lines[j+1][i] = (char)CUSTOM_CHAR_END;
            }
            if(j < 3)
            {
                lines[j+1][i] = (char)((barHeight[i]-1)/3 + CUSTOM_CHAR_START);
            }
        }

        for(byte line = 1; line < 4; line++)
        {
            brickletLCD.WriteLine((byte)(4-line), 0, new string(lines[line]));
        }
    }

    static private void UpdateMinMaxAvg()
    {
        switch(buttonPressedCounter[2] % 4)
        {
            case MODE_ILLUMINANCE:
                UpdateMinMaxAvgWrite("Illuminance    " + TimeFromSeconds(illuminanceQueue.Count),
                                     "lx",
                                     GetMinMaxAvg(illuminanceQueue));
                break;

            case MODE_HUMIDITY:
                UpdateMinMaxAvgWrite("Humidity       " + TimeFromSeconds(humidityQueue.Count),
                                     "%RH",
                                     GetMinMaxAvg(humidityQueue));
                break;

            case MODE_AIR_PRESSURE:
                UpdateMinMaxAvgWrite("Air Pressure   " + TimeFromSeconds(airPressureQueue.Count),
                                     "hPa",
                                     GetMinMaxAvg(airPressureQueue));
                break;

            case MODE_TEMPERATURE:
                UpdateMinMaxAvgWrite("Temperature    " + TimeFromSeconds(temperatureQueue.Count),
                                     ((char)0xDF) + "C",
                                     GetMinMaxAvg(temperatureQueue));
                break;
        }
    }

    static private void UpdateMinMaxAvgWrite(string title, string unit, double[] values)
    {
        String min = string.Format("Min: {0,2:##.00} {1}", values[0], unit);
        String max = string.Format("Max: {0,2:##.00} {1}", values[1], unit);
        String avg = string.Format("Avg: {0,2:##.00} {1}", values[2], unit);
        brickletLCD.WriteLine(0, 0, title);
        brickletLCD.WriteLine(1, 0, min);
        brickletLCD.WriteLine(2, 0, avg);
        brickletLCD.WriteLine(3, 0, max);
    }

    static private void UpdateTime()
    {
        string line0 = DateTime.Now.ToString("HH:mm:ss");
        string line1 = DateTime.Now.ToString("dddd");
        string line2 = DateTime.Now.ToString("D");
        brickletLCD.WriteLine((byte)0, (byte)((LINE_LENGTH-line0.Length)/2), line0);
        brickletLCD.WriteLine((byte)1, (byte)((LINE_LENGTH-line1.Length)/2), UTF16ToKS0066U(line1));
        brickletLCD.WriteLine((byte)2, (byte)((LINE_LENGTH-line2.Length)/2), UTF16ToKS0066U(line2));
    }

    static private void UpdateSwitch()
    {
        switch(buttonPressed)
        {
            case UPDATE_TYPE_STANDARD: UpdateStandard(); break;
            case UPDATE_TYPE_GRAPH: UpdateGraph(); break;
            case UPDATE_TYPE_MIN_MAX_AVG: UpdateMinMaxAvg(); break;
            case UPDATE_TYPE_TIME: UpdateTime(); break;
        }
    }

    static private void Update(object state)
    {
        if(Double.IsNaN(latestIlluminance) ||
           Double.IsNaN(latestHumidity) ||
           Double.IsNaN(latestAirPressure) ||
           Double.IsNaN(latestTemperature))
        {
            return;
        }

        illuminanceQueue.Enqueue(latestIlluminance);
        if(illuminanceQueue.Count > 60*60*24)
        {
            illuminanceQueue.Dequeue();
        }

        humidityQueue.Enqueue(latestHumidity);
        if(humidityQueue.Count > 60*60*24)
        {
            humidityQueue.Dequeue();
        }

        airPressureQueue.Enqueue(latestAirPressure);
        if(airPressureQueue.Count > 60*60*24)
        {
            airPressureQueue.Dequeue();
        }

        temperatureQueue.Enqueue(latestTemperature);
        if(temperatureQueue.Count > 60*60*24)
        {
            temperatureQueue.Dequeue();
        }

        UpdateSwitch();
    }

    static void Main()
    {
        ipcon = new IPConnection();
        while(true)
        {
            try
            {
                ipcon.Connect(HOST, PORT);
                break;
            }
            catch(System.Net.Sockets.SocketException e)
            {
                System.Console.WriteLine("Connection Error: " + e.Message);
                System.Threading.Thread.Sleep(1000);
            }
        }

        ipcon.EnumerateCallback += EnumerateCB;
        ipcon.Connected += ConnectedCB;

        while(true)
        {
            try
            {
                ipcon.Enumerate();
                break;
            }
            catch(NotConnectedException e)
            {
                System.Console.WriteLine("Enumeration Error: " + e.Message);
                System.Threading.Thread.Sleep(1000);
            }
        }

        timer = new Timer(Update, null, TimeSpan.Zero, TimeSpan.FromSeconds(1));

        System.Console.WriteLine("Press enter to exit");
        System.Console.ReadLine();
        ipcon.Disconnect();
    }
}