I have been working with my mbed LPC1768 development board on my Windows Vista Entreprise (SP2) 32bit system, and all was working OK.

Till yesterday, when my serial communication, strangly enough, didn't work anymore. Then I saw in device manager an '!' with the mbed serial port. (This looks like this problem: http://mbed.org/forum/mbed/topic/243/?page=1#comment-1108 )

I couldn't get it working so what I did was uninstalling the mbed driver and reinstall the driver again. However, now problems increased. If I now have a look in my device manager I see no mbed port appear anymore but only an 'mbed composite device' in the 'other devices' category. (This looks somewhat similar to this problem: http://mbed.org/forum/bugs-suggestions/topic/1186/?page=1#comment-6034 )

Windows keeps bugging me about installing the proper driver. And I de-installed and re-installed a few times (with and without rebooting) but all this doesn't seem to help.

Please advice in how to get things up and running again?

Thanks!

p.s. I am not sure but in my vague memory I have some doubt about Windows installing some updates yesterday. So this is different between the last time I used mbed and the first time problems occured. Probably it is not related but to be sure, how can I check this? I have no stored point to let windows recover to.

Hi,

It is always a good idea to remove all ghosted devices together with the one with the exclamation mark.

I wrote a tool for it at http://ghostbuster.codeplex.com

After that (and maybe a reboot) plug in the device once more and it should run ok.

Thre should be no need to uninstall drivers unless you updated them (in which case the rollback option in the device properties is better).

Wim

Dear Wim,

Thank you for proposing a solution to my problem. I did what you suggested, using your software tool. Unfortunately this does not provide a solution to my problem. I still remain with the following:

1. plug in the mbed to a USB port of my computer 2. windows starts asking me to install the drivers for the device, this obviously doesn't work out as it can not find the correct ones(I know I have to use the driver as provided by mbed (see my first post)). 3. I end up with a 'mbed composite device' in device manager in the category of 'other devices'. So no mbed port available in the category 'Ports (COM & LPT)'.

I have read everything I could find on the forum and the mbed website about serial communication, windows & drivers etcetera but none of the problems or suggested actions relates to my problem (to my best knowledge).

Can somebody please provide me with ideas or fixes I could try?

Thank you again!

Hi,

Did you check the drivers are present in the windows drivers directory (c:\windows\system32\drivers). There should be two drivers called mbedComposite.sys and mbedSerial.sys (or with a _x64 suffix if your running a windows x64 version).

You might try to remove the device AND remove the two drivers. Then re-install the drivers with the installer (mbedWinSerial_16466.exe or something alike) Then plugin the device.

If you want to remove even more you can also delete the oem*.inf file from c:\windwows\inf (you have to search the oem*.inf files and delete the one(s) containing mbed stuff (and also delete the compiled inf file with the same name but a *.pnf extension).

The exclamation problems are btw hard to solve. Windows just tells the device is not functioning.

For some devices it sometimes works to disable the device in the device manager and re-enable it (when disabled it should display a red cross).

Removing the device, shutdown the pc, plug the device in and start the pc is also a cure sometimes.

Wim

Wim,

removing the device AND the two drivers AND removing the corresponding oem*.inf and .pnf files worked! After doing so, and a reboot, I was able to install the mbed driver correctly again. After this the device manager nicely showed my mbed board in the ports category. However, an exclamation sign was present again (but I got rid of the 'mbed composite device' issue so that's step one.

The exclamation sign I solved by setting the com port to another number and after this disabling and enabling it again. Now the exclamation mark dissappeared.

So the initially described problem seems solved here. However, my mbed board still doesn't respond to simple serial commands I sent, as it used to do before problems occured. But it might be better to have a more thorough look on this myself first (or if you can relate it to the problem please let me know).

Thanks

And also the communication is up and running again after an additional reboot!!

So the solution as proposed by Wim worked for me! Thanks.

Hi

Ghosted serial devices still block the reuse of com ports.

You see it when remapping a serial.

The list of available ports is then showing less ports then expected.

Removing the ghost frees the port jfor remapping.