just to close things off, the solution was to use the right resistor values.

did not know about having to use certain ohms depending on the capacitance of the bus.

When I was using one device, I had the right resistance and it worked.

using two devices, the capacitance changed, but the resistance stayed the same, which did not let the bus function properly.

the more devices you have, the less resistance you need.

Hope this will help someone who got stuck like i did

Hi Paolo,

Thanks for doing the hard yards.

I have got the following NFC board http://www.aliexpres...2038722238.html

Have configured it to use I2C, but not having any luck communicating with it.

Using 2.2KOhm pull up resistors and have tried both 3.3V and 5V.

The Execute in I2CWrite fails with write = 0

Any idea on what it could be?

PN532 is a specific chip from one company only, right?

I have an I2c lux meter and that works fine.

NP2

FW 4.3.1

Have you looked at this for multiple devices on the I2C bus?
http://forums.netdui...e-i2cbus-class/

Thanks for the reply and sorry for the late response.

I am using something similar to the second post in the link.

do you have the 2 devices on the same I2C address, thats the first thing you have to tackle.

Thanks for the reply.

the PH sensor has addr 0x4D and the Lux sensor has 0x23

the thing i do not understand is that even though the second sensor is not even initialized, the reading of the first one fails.

the app is setup to only read the Lux sensor and by just adding the second hardware to the bus, reading of the firs one fails.

Hi,

If I use one device, all is good.

If I connect a second one, without even communicating with it, I cannot get any more readings.

My base class creates only one I2CDevice and for a read, the configuration is assigned and then the "Execute" is called inside a lock of the device.

Have found a post of someone using a similar technique: http://forums.netdui...bus/#entry41552

Only difference I have, is that I create the array inside the function and throw an exception in case of an error.

I have no idea where I am going wrong.

Would be great, if someone has an idea or comment.

Thanks

Martin

Netduino Plus 2, firmware 4.3.1

I2C Lux sensor

I2C PH meter

Not a nice workaround, but It seems all good now.

have changed

m_oWriteFile.Flush();

to

VolumeInfo.GetVolumes()[0].FlushAll();

and the app has been running at least twice as long as before.

will see if it still runs after hours.

Hi,

I have updated my NP2 to 4.3.1 about 3 weeks ago and also upgraded my app to .NET 4.3.

Now I am noticing that the file write seems to kill the whole app.

The app is multi threaded, reading different sensors, which write the data to a file.

i am using the file as a buffer, as the network may be cut, but the app should not miss any readings.

The write is inside a lock, so the threads will not be able to use the same file obj at the same time.

I open the file once in a singleton obj and use it to write and flush the data to file.

Since there is a lot of data going into the file, I do not want to open, wite, flush and close it all the time.

The app can log dozens of readings per sec.

Below is the line where the file gets opened and below that how the data get written to the file.

The last log that is printed is "WriteToFile lock" and after that the whole app just dies.

All thread seem to get blocked.

I would expect multiple "WriteToFile begin" lines, until all thread are stuck at the "WriteToFile begin"

e.g.

WriteToFile begin

WriteToFile lock

WriteToFile begin

WriteToFile begin

WriteToFile begin

WriteToFile begin

m_oWriteFile = new FileStream(m_sLogFileName, FileMode.OpenOrCreate, FileAccess.Write);

   protected void WriteToFile(byte[] a_sData)
   {
      Debug.Print("WriteToFile begin");
      lock (m_oFileLock)
      {
         Debug.Print("WriteToFile lock");
         try
         {
            if (m_oWriteFile != null)
            {
               m_oWriteFile.Write(a_sData, 0, a_sData.Length);
               m_oWriteFile.Flush();
            }
         }
         catch (Exception ex)
         {
            Debug.Print("EXCEPTION: CSdCard:WriteToFile - " + (ex.InnerException == null ? ex.Message : ex.InnerException.Message));
         }
      }
      Debug.Print("WriteToFile end");
   }

With an older firmware version the code above worked fine.

Has anyone got an idea what this could be?

Bug in 4.3.1?