Hi,
I bought some DS1631Z thermo sensors, but I have big troble to communicate through I2C (using one per netduino),
I think I try every example I found through google, but nothing work for me 
If you know about any working code, please let me know, or
if itās not very difficult, my config is all A pins grounded for someone who know I2C and can write code example fo me.
Thanks so much, after third day of trying, I think itās impossibleā¦
@ cyberh0me - Hi, thanks for quick reply, I try this example too, but this ends with unexpected error and program exit without more info.
You may need pullup resistors (2.2k) on the SDA/SCL lines (if you are using a Netduino). I am pretty sure the Netduino does not have them.
@ munderhill - Hello, thank, I have it.
All three A pins grounded, ground grounded, vcc I try with 3,3 and 5V too, no change and SD and SC are connected to 3,3/5V through 2,2/4,7K resistor.
Post your code
@ munderhill - at last, I try ithis code:
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;
namespace NetduinoApplication2
{
public class Program
{
public static void Main()
{
//create I2C object
//note that the netmf i2cdevice configuration requires a 7-bit address! It set the 8th R/W bit automatically.
I2CDevice.Configuration con = new I2CDevice.Configuration(0xAA, 400);
I2CDevice MyI2C = new I2CDevice(con);
// Create transactions
// We need 2 in this example, we are reading from the device
// First transaction is writing the "read command"
// Second transaction is reading the data
I2CDevice.I2CTransaction[] xActions = new I2CDevice.I2CTransaction[2];
// create write buffer (we need one byte)
byte[] RegisterNum = new byte[1] { 2 };
xActions[0] = I2CDevice.CreateWriteTransaction(RegisterNum);
// create read buffer to read the register
byte[] RegisterValue = new byte[1];
xActions[1] = I2CDevice.CreateReadTransaction(RegisterValue);
// Now we access the I2C bus using a timeout of one second
// if the execute command returns zero, the transaction failed (this
// is a good check to make sure that you are communicating with the device correctly
// and don't have a wiring issue or other problem with the I2C device)
if (MyI2C.Execute(xActions, 1000) == 0)
{
Debug.Print("Failed to perform I2C transaction");
}
else
{
Debug.Print("Register value: " + RegisterValue[0].ToString());
}
}
}
}
before:
Dim config As I2CDevice.Configuration = New I2CDevice.Configuration(1, 100)
Dim i2c As I2CDevice = New I2CDevice(config)
Dim write As Byte = ""
Dim read As byte = new byte[1]
' create I2C write and read transaction
Dim i2cTx As I2CDevice.I2CTransaction = New I2CDevice.I2CTransaction(1)
i2cTx(0) = I2CDevice.CreateWriteTransaction(write)
i2cTx(1) = I2CDevice.CreateReadTransaction(read)
' execution
i2c.Execute(i2cTx, I2C_TIMEOUT)
and before I found some libraries, but nothing with good result.
If I am reading the datasheet correctly, I think the address starts at 0x48 and goes through 0x4F, so with all the address lines tied to ground the would be 0x48.
@ munderhill - app still exit, but now i pause it at end and see, there was a debug message: āFailed to perform I2C transactionā
I think itās because iām not sending proper ācodeā
If iām right, I must write ā0x51ā and then read ā0xAAā? and if yes, then I donāt know where I must enter values, can you help me?
(sorry for maybe basic question, but i never meet i2c before)
Thanks
Try this.
var xActions = new I2CDevice.I2CTransaction[1];
// START Conversions
xActions[0] = I2CDevice.CreateWriteTransaction(new byte[] { 0x51 });
I2C.Execute(xActions, 1000);
Thread.Sleep(5);
// READ Temp
xActions[0] = I2CDevice.CreateWriteTransaction(new byte[] { 0xAA });
I2C.Execute(xActions, 1000);
Thread.Sleep(5);
var data = new byte[2];
xActions[0] = I2CDevice.CreateReadTransaction(data);
I2C.Execute(xActions, 1000);
Thread.Sleep(5);
// STOP Conversions
xActions[0] = I2CDevice.CreateWriteTransaction(new byte[] { 0x22 });
I2C.Execute(xActions, 1000);
Thread.Sleep(5);
@ munderhill - Iām happy for your code, it looks like what I need, but I still have no answer from sensor
iām using this code, but if I break code at last debug print, data[0] and data[1] is still 0x00:
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;
namespace NetduinoApplication3
{
public class Program
{
public static void Main()
{
// write your code here
I2CDevice.Configuration con = new I2CDevice.Configuration(0x48, 400);
I2CDevice I2C = new I2CDevice(con);
//I2CDevice.I2CTransaction[] xActions = new I2CDevice.I2CTransaction[2];
var xActions = new I2CDevice.I2CTransaction[1];
// START Conversions
xActions[0] = I2CDevice.CreateWriteTransaction(new byte[] { 0x51 });
I2C.Execute(xActions, 1000);
Thread.Sleep(5);
// READ Temp
xActions[0] = I2CDevice.CreateWriteTransaction(new byte[] { 0xAA });
I2C.Execute(xActions, 1000);
Thread.Sleep(5);
var data = new byte[2];
xActions[0] = I2CDevice.CreateReadTransaction(data);
I2C.Execute(xActions, 1000);
Thread.Sleep(5);
// STOP Conversions
xActions[0] = I2CDevice.CreateWriteTransaction(new byte[] { 0x22 });
I2C.Execute(xActions, 1000);
Thread.Sleep(5);
Debug.Print(data[0].ToString());
Debug.Print(data[1].ToString()); // breakpoint here
//byte[] RegisterNum = new byte[1] { 2 };
//xActions[0] = I2CDevice.CreateWriteTransaction(RegisterNum);
//byte[] RegisterValue = new byte[1];
//xActions[1] = I2CDevice.CreateReadTransaction(RegisterValue);
//if (I2C.Execute(xActions, 1000) == 0)
//{
// Debug.Print("Failed to perform I2C transaction");
//}
//else
//{
// Debug.Print("Register value: " + RegisterValue[0].ToString());
//}
Thread.Sleep(10000000);
}
}
}
@ munderhill - Dear Munderhill, now sensor works perfectly,
last trobles are my mistake, I have switched SC pin with SD.
Thank you very very very very very much for your help and time, youāre great 
Peter
Glad to help!