Communication problem Arduino Mega 2560 - PC

Hello,

we have a project where we use an Arduino Mega 2560 for datalogging. The arduino sends
periodically (2s cycle) a string containing different sensor values. On the PC (Windows 7 and Windows XP) we use logview
for visualization (www.logview.info/) which works well for our purposes.
The stringformat
for logview is described here: http://www.logview.info/cms/d_formatbeschreibung.phtml

Our problem is that logview hangs up from time to time. The serial logging stops and logview can't
open the COM-Port anymore. The only solution is to unplug and reconnect the USB-cable to the Arduino. Unfortunately, this
isn't an acceptable solution for us.

What we have tried so far:

  • We removed all sensors/actors from the Arduino Mega 2560 and sent only dummy strings over USB -> logview still hangs up
  • We reduced the baudrate --> it seems, that the device doesn't hangs up so often (but still hangs up)
  • We used shorter USB-cables --> it seems, that the device doesn't hangs up so often (but still hangs up)
  • We used on the PC a simple PC-program writing serial data to a file (instead of logview) --> also hangs up
  • We connected an additional arduino USART/USB converter to the second USART from the Arduino and sent the same strings over both UARTS. On PC we watched both ports with logview and putty -> both hanged up

You have any idea? We think that it could be

  • problem with ground
  • problem with windows

Best regards

I forgot: We tested this also with different PC’s.

Best regards