Hi , I am not very familiar with WINCE and so I hope u can help me .. is it possible for the C# application to communicate (through I2C.dll) with any device supporting I2C interface connected to the mini2440 ?? is there any (C#) sample code to do that ?? i know that is possible under "C" , like the code in the link http://www.domodom.fr/spip/Utiliser-le-driver-I2C-dans-une.html?lang=en but what about C# ????? Hope u can help me ... Msallati..
I had the same problem and I made this solution: With visual studio, I created a MFC DLL smart device app in C++, a static DLL. I inserted this C++ code and call this DLL in C# with DllImport function. My program runs, but I dont know how to run i2c better and made my own application.
Thank u so much for this solution!! I am going to try it now :)
I can not write i2c read/write function .so could you send for me i2c c# code regardly sir
Hello, My GPIO driver uses the same driver model that the i2c driver. You can find on my website a c# sample of use of this driver, maybe it will help you... Domodom
Hi,
I have a solution. Please note that I do not print value on any control
form.
Here's the code:
/*
********************************************************************************
**********
* Author: Benoit Papineau
* Date: 27.04.2011
*
* Description: Basic code to read and write on the Eeprom of the Mini2440
*******************************************************************************
*************/
using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
// compile with: /unsafe
namespace TestI2C
{
public partial class Form1 : Form
{
//Invoke methods
[DllImport("coredll.dll", EntryPoint = "DeviceIoControl",
SetLastError = true)]
internal static extern int DeviceIoControlCE(int hDevice, int
dwIoControlCode, byte[] lpInBuffer, int nInBufferSize, byte[] lpOutBuffer,
int nOutBufferSize, ref int lpBytesReturned, IntPtr lpOverlapped);
[DllImport("coredll", SetLastError = true)]
private static extern IntPtr CreateFile(string lpFileName, uint
dwDesiredAccess, uint dwShareMode, IntPtr lpSecurityAttributes, uint
dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile);
[DllImport("coredll.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool CloseHandle(IntPtr hObject);
//Found on pinvoke.net
public const UInt32 GENERIC_ALL = 0x10000000;
public const UInt32 GENERIC_READ = 0x80000000;
public const UInt32 GENERIC_WRITE = 0x40000000;
public const UInt32 GENERIC_EXECUTE = 0x20000000;
public const UInt32 FILE_SHARE_READ = 1;
public const UInt32 FILE_SHARE_WRITE = 2;
public const UInt32 OPEN_EXISTING = 3;
//Found with I2C driver
public const Int32 IOCTL_I2C_READ = 262144;
public const Int32 IOCTL_I2C_WRITE = 262148;
public const Int32 IOCTL_I2C_GET_FASTCALL = 262152;
/// <summary>
/// Struct for I2C driver
/// </summary>
unsafe struct _I2C_IO_DESC {
public UInt32 SlaveAddr; // Target Slave Address
public byte WordAddr; // Starting Slave Word Address
public byte* Data; // pBuffer
public UInt32 Count; // nBytes to read/write
}
/// <summary>
/// I2C Handler
/// </summary>
private static IntPtr _i2cFile;
//Migth be useless
int _rCount = 0;
public Form1()
{
InitializeComponent();
}
private void OpenHandle0()
{
//Open the channel 0
_i2cFile =
CreateFile
("I2C0:",
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
IntPtr.Zero,
OPEN_EXISTING,
0,
IntPtr.Zero
);
}
private void CloseHandle0()
{
CloseHandle(_i2cFile);
}
private void bttnRead_Click(object sender, EventArgs e)
{
unsafe
{
byte[] data = new byte[16];
fixed (byte* p = data) //Make sure that garbage collector
won't move the data
{
_I2C_IO_DESC i2cMsg;
i2cMsg.SlaveAddr = 0xA1; //Eeprom Adress
i2cMsg.WordAddr = 0; //Start Adress
i2cMsg.Count = 16; //Nb of byte to read
i2cMsg.Data = p; //Pointer
byte[] buffer = ObjectToByteArray(i2cMsg);
OpenHandle0();
DeviceIoControlCE((int)_i2cFile, IOCTL_I2C_READ,
buffer, buffer.Length, buffer, 0, ref _rCount, IntPtr.Zero);
CloseHandle0();
_I2C_IO_DESC i2cRead =
ByteArrayToObject<_I2C_IO_DESC>(buffer);
//*****At this point, "data" contains the content of
the eeprom*****
}
}
}
private void bttnWrite_Click(object sender, EventArgs e)
{
//Some data
byte[] data = new byte[16];
data[0] = 48;
data[1] = 48;
data[2] = 48;
data[3] = 48;
data[4] = 48;
data[5] = 48;
data[6] = 48;
data[7] = 48;
data[8] = 48;
data[9] = 48;
data[10] = 48;
data[11] = 48;
data[12] = 48;
data[13] = 48;
data[14] = 48;
data[15] = 48;
unsafe
{
fixed (byte* p = data) //Make sure that garbage collector
won't move the data
{
_I2C_IO_DESC i2cMsg;
i2cMsg.SlaveAddr = 0xA1; //Eeprom Adress
i2cMsg.WordAddr = 0; //Start Adress
i2cMsg.Count = 16; //Nb of byte to read
i2cMsg.Data = p; //Pointer
byte[] buffer = ObjectToByteArray(i2cMsg);
OpenHandle0();
DeviceIoControlCE((int)_i2cFile, IOCTL_I2C_WRITE,
buffer, buffer.Length, buffer, 0, ref _rCount, IntPtr.Zero);
CloseHandle0();
//*****At this point, i2cMsg is sent to the eeprom*****
}
}
}
/// <summary>
/// Convert an object to a byte array. Will not work with dynamic
size object
/// This method is based from an example on codeproject.com
(http://www.codeproject.com/KB/cs/C__Poiter.aspx)
/// </summary>
/// <param name="obj">Object to convert</param>
/// <returns>Array of bytes</returns>
public byte[] ObjectToByteArray(object obj)
{
int Length = Marshal.SizeOf(obj);
byte[] byteArray = new byte[Length];
IntPtr ptr = Marshal.AllocHGlobal(Length);
Marshal.StructureToPtr(obj, ptr, false);
Marshal.Copy(ptr, byteArray, 0, Length);
Marshal.FreeHGlobal(ptr);
return byteArray;
}
/// <summary>
/// Convert a byte array to an object of type T. Will not work with
dynamic size object
/// This method is based from an example on codeproject.com
(http://www.codeproject.com/KB/cs/C__Poiter.aspx)
/// </summary>
/// <typeparam name="T">Type of the returned object</typeparam>
/// <param name="byteArray">Byte array to convert</param>
/// <returns>Object from byte array</returns>
public T ByteArrayToObject<T>(byte[] byteArray)
{
T obj;
int Length = Marshal.SizeOf(typeof(T));
IntPtr ptr = Marshal.AllocHGlobal(Length);
Marshal.Copy(byteArray, 0, ptr, Length);
obj = (T)Marshal.PtrToStructure(ptr, typeof(T));
Marshal.FreeHGlobal(ptr);
return obj;
}
}
}
Hi Bpapineau! 1st of all Thanks for the source code, i am trying to use i2c for my ok6410 board (http://arm9board.net/sel/prddetail.aspx?id=354&pid=200) , i need to ask what parameters do i need to change to use your code, I changed the lpFileName to prefix of my dll, driver loads perfectly the DeviceIoControl works returns no error but i am unable to read and write, the number of bytes returned (lpBytesReturned) is 0. Any clue what could be the issue ? Thanks. regards usama
Thank you Benoit, your code is very helpful! If you're ever in Slovenia I'm buying you a beer :)
To send and read data from Windows and C#, VB.NET IN I2C or SPI, I found that the www.Nusbio.net device is easier to use because all the samples are open source in in C# or VB.NET (and they are a lot of them). The source are implemented in different layer, first how to deal at a high level with an I2C EEPROM, then with a debugger can drill down and look into more detail into the I2C protocol. They support I2C EEPROM, LCD, A lot of the Adafruit I2C Devices. They support all SPI EEPROM (Faster), of 8x8 or 328x LED Matrix based on the MAX7219 chip. It might sabe you time