Well… I’ve been spending some quality time with the .NET Micro Framework the last couple weeks. I’ve been always interested in electronics and the inner parts of devices. I even bought some Atmel AVR microcontrollers and a handful of components last year to get started with microcontrollers, but it didn’t work out (so many hobby projects, so less time…).
In May/June I discovered NETMF and I just had to try it. Embedded devices driven by C# code is just a dream come true.
So after some surfing I ordered a GHI Electronics EMX Development System to get started. Since I’m not that good at time management (and it’s holiday season with lots of social obligations) I didn’t come as far as I hoped to be. BUT… I would like to share some piece of code, though.
While working on a secret project called “BeerGuard” I created a small class to use the SparkFun SerLCD (16×2 and 20×4) with NETMF. I’m probably not the only one who has written such a class, but I’ll dump it on the Internet anyway.
Be aware that this is a quick implementation to get me started real quick. Not everything is tested and there is probably a lot of code improvement possible. I hope this might be a starting point for some people. Please don’t start bashing my coding style and please… post improvements and corrections!
using System;
using System.IO.Ports;
namespace LXIT.Hardware
{
public sealed class SerLCD
{
public enum Direction { Left, Right }
public enum DisplayType { C16L2, C16L4, C20L2, C20L4 }
public enum Status { On, Off }
private readonly SerialPort _serialPort;
private readonly DisplayType _displayType;
public SerLCD(string portName) : this(portName, DisplayType.C16L2)
{}
public SerLCD(string portName, DisplayType displayType)
{
// Defaults for SerialPort are the same as the settings for the LCD, but I'll set them explicitly
_serialPort = new SerialPort(portName, 9600, Parity.None, 8, StopBits.One);
_displayType = displayType;
}
public void ClearDisplay()
{
Write(new byte[] { 0xFE, 0x01 });
}
public void MoveCursor(Direction direction)
{
MoveCursor(direction, 1);
}
public void MoveCursor(Direction direction, int times)
{
byte command;
switch (direction)
{
case Direction.Left: command = 0x10; break;
case Direction.Right: command = 0x14; break;
default: return;
}
for (int i = 0; i < times; i++)
{
Write(new byte[] { 0xFE, command });
}
}
public void Open()
{
if (!_serialPort.IsOpen)
_serialPort.Open();
}
public void SaveAsSplashScreen()
{
Write(new byte[] { 0x7C, 0x0A });
}
public void Scroll(Direction direction)
{
Scroll(direction, 1);
}
public void Scroll(Direction direction, int times)
{
byte command;
switch (direction)
{
case Direction.Left: command = 0x18; break;
case Direction.Right: command = 0x1C; break;
default: return;
}
for (int i = 0; i < times; i++)
{
Write(new byte[] { 0xFE, command });
}
}
public void SetBlinkingBoxCursor(Status status)
{
byte command;
switch (status)
{
case Status.On: command = 0x0D; break;
case Status.Off: command = 0x0C; break;
default: return;
}
Write(new byte[] { 0xFE, command });
}
public void SetBrightness(int brightness)
{
if (brightness < 128 || brightness > 157)
throw new ArgumentOutOfRangeException("brightness", "Value of brightness must be between 128-157.");
Write(new byte[] { 0x7C, (byte)brightness });
}
public void SetCursorPosition(int line, int column)
{
if ((_displayType == DisplayType.C16L2 || _displayType == DisplayType.C16L4) && (column < 1 || column > 16))
throw new ArgumentOutOfRangeException("column", "Column number must be between 1 and 16.");
if ((_displayType == DisplayType.C20L2 || _displayType == DisplayType.C20L4) && (column < 1 || column > 20))
throw new ArgumentOutOfRangeException("column", "Column number must be between 1 and 20.");
if ((_displayType == DisplayType.C16L2 || _displayType == DisplayType.C20L2) && (line < 1 || line > 2))
throw new ArgumentOutOfRangeException("line", "Line number must be 1 or 2.");
if ((_displayType == DisplayType.C16L4 || _displayType == DisplayType.C20L4) && (line < 1 || line > 4))
throw new ArgumentOutOfRangeException("line", "Line number must be between 1 and 4.");
int[] startPos16 = { 0, 64, 16, 80 };
int[] startPos20 = { 0, 64, 20, 84 };
int charPos;
switch (_displayType)
{
case DisplayType.C16L2:
case DisplayType.C16L4:
charPos = startPos16[line - 1] + (column - 1);
break;
case DisplayType.C20L2:
case DisplayType.C20L4:
charPos = startPos20[line - 1] + (column - 1);
break;
default:
return;
}
Write(new byte[] { 0xFE, (byte)(charPos + 0x80) });
}
public void SetDisplay(Status status)
{
byte command;
switch (status)
{
case Status.On: command = 0x0C; break;
case Status.Off: command = 0x08; break;
default: return;
}
Write(new byte[] { 0xFE, command });
}
public void SetDisplayType(DisplayType displayType)
{
switch (displayType)
{
case DisplayType.C16L2:
Write(new byte[]{0x7C, 0x04}); // 16 characters
Write(new byte[]{0x7C, 0x06}); // 2 lines
break;
case DisplayType.C16L4:
Write(new byte[]{0x7C, 0x04}); // 16 characters
Write(new byte[]{0x7C, 0x05}); // 4 lines
break;
case DisplayType.C20L2:
Write(new byte[]{0x7C, 0x03}); // 20 characters
Write(new byte[]{0x7C, 0x06}); // 2 lines
break;
case DisplayType.C20L4:
Write(new byte[]{0x7C, 0x03}); // 20 characters
Write(new byte[]{0x7C, 0x05}); // 4 lines
break;
}
}
public void SetUnderlineCursor(Status status)
{
byte command;
switch (status)
{
case Status.On: command = 0x0E; break;
case Status.Off: command = 0x0C; break;
default: return;
}
Write(new byte[] { 0xFE, command });
}
public void ToggleSplashScreen()
{
Write(new byte[] { 0x7C, 0x09 });
}
public void Write(byte buffer)
{
Write(new[] { buffer });
}
public void Write(byte[] buffer)
{
Open();
_serialPort.Write(buffer, 0, buffer.Length);
}
public void Write(char character)
{
Write((byte)character);
}
public void Write(string text)
{
byte[] buffer = new byte[text.Length];
for (int i = 0; i < text.Length; i++)
{
buffer[i] = (byte)text[i];
}
Write(buffer);
}
}
}