Windows 10, STM32L15X - VIRTUAL COM PORT - Problems

geraldloh · ‎2015-08-05

Posted on August 05, 2015 at 21:53

Hi,

(Sorry, translated by ...)

I have questions about which I am not find anything on the Internet.

I have with examples and advice from the web a virtual com port for STM32LXX MD and HD devices created.

This works in your own applications under XP, Win7, Win 8, Win 8.1 as x32 and x86 machines with no problems. Send and receive, hot-plug, data rates up to 400 kB, there are no problems.

Windows side, I have the STM drivers 1.3.1 or 1.4.0 can use as trouble-free.

My Windows programs use GetDefaultCommConfig, CreateFile, SetCommState, GetCommState, WaitForSingleObject ... ... to manage the ComPorts. Other virtual com ports (eg CP210 devices) I can speak without problems with my software under Windows 10.

Under Windows 10 but does my created virtual Com port no longer!

The STM drivers can be good and error-free installation, the status code is OK = 0x0. Connected devices are immediately recognized and duly incorporated as a COM device COMXX. Everything looks good.

I can sign by the PC to send and receive them on the microcontroller via USB.

But, mark returned but do not come to the PC. No character comes back. Windows 10 only.

Has anyone had similar experiences of you?

Have any of you STM CDC Examples under Windows 10 brought to work?

Is a modified Windows 10 functionality to blame? (A note would be that eg FTDI on 28/07/2015 new drivers brought out.)

If STM implement new drivers for Windows 10?

Could my PC (and other virtual machines) be guilty despite an OK from the driver?

If other STM-CDC examples run under Windows 10, where I would have to begin to repair?

Thanks for any information I can get.

Best regards

Gerald Loh

#vcp #stm32 #usb #cdc #windows10

geraldloh · ‎2015-08-10

Posted on August 10, 2015 at 20:26

I have

solved the problem

for the time being

.

Under

Windows

10

(

and

only on Windows

10

)

suggests

to me

the PC side

the

Microsoft

function

ReadFile

fails

, it returns

the

p

ermanent

''

GetLastWin32Error

''

ErrorIOPending

''

.

In fact,

does this

function

until

this

error message

.

The

sign

,

which

you

must

read aloud

ClearCommError

/

ComStat.InQue

(

ie

the

ReadCount

)

are

,

nevertheless

transferred successfully

despite the error message

in

the buffer

.

If

I ignore

the error message

,

I can

again

communicate

via

VCP

.

Uses the

class

Serial Port

(

.NET

System.IO.Ports

)

one seems

to be working

to communicate

well

.

(

This

I have tested

only

a few

bytes

)

.

Whether

the fault

the

''

standard

device classes

''

or

''

my

controller

functionality

''

is now

attributed to

the future

will probably

show

...

fenyvesr · ‎2015-11-07

Posted on November 07, 2015 at 22:49

Hi Gerald!

How exactly did you solve this problem. because I have the same problem?

Best regards, Robert

yymo1019 · ‎2016-05-11

Posted on May 12, 2016 at 08:24

Hello.. Gerald

We have the similar problem in Win10.

When we disconnected the usb port, Windows CPU load goes up suddenly. and there are so many errors.

We want to know how did ignore the error?

Could you be more specific? or Would you mind sharing your code?

AvaTar · ‎2016-05-12

Posted on May 12, 2016 at 09:57

The original post is more than 8 month old, and obviously auto-translated into english.

That would suggest that the OP is not monitoring the forum.

>We want to know how did ignore the error?

The function/method names he mentioned are part of the Win API, so it seems he was speaking about a Windows based tool using the VCP.

Trying to interpret the auto-translated text, he suggests to clear the COM error with

ClearCommError

(), and read out the received character(s) anyway.

That would not be helpful on Desktop /GUI level.