Recent Posts

21

Parallel Port / ParallelPort.DLL has bad format

« Last post by SpiritualMadMan on March 30, 2023, 02:37:34 pm »

I am just starting to "play" with the parallel port and I downloaded a demo program Parallel Port Control in C# and I am running under Windows 10 and using Visual Studio 2019.

How do I fix this or download a replacement DLL

22

Serial Ports / Re: D Tech DT-5019 is slow

« Last post by Renate on March 20, 2023, 09:21:43 pm »

... set the baud for 115200. It worked, in a way. I am no longer getting errors on the echoed characters but the overall transfer rate is still the same, about 1000 Mbps.

Huh? 115.2 kbps makes sense. I don't know what you mean by 1000 Mbps.

Various serial chips do some buffering before they put a buffer of received data on the USB.
In Linux world there is ioctl TIOCSSERIAL and ASYNC_LOW_LATENCY to use the minimum time.
FTDI chips have custom vendor control transfers:

Code: [Select]

#define FTDI_SET_LATENCY_TIMER 0x09
#define FTDI_GET_LATENCY_TIMER 0x0aThen there's what kind of timeouts you are using in your Windows DCB.

23

USB / Re: Should a modern USB device ever have cls/sub/ver in the device descript?

« Last post by Renate on March 15, 2023, 03:20:17 pm »

The USB IF added iadclasscode_r10.pdf in 2003.
It deals with using ef/02/01 in the device descriptor.
This is a safety measure to prevent the "new" (2003) IAD from wreaking havoc with "legacy" (i.e. older than 2003) OSes.

So when you make your brand new device you could put ef/02/01 in the device descriptor to make sure that there are no problems running on Windows 95.
But I won't.

24

USB / Re: Window Password or Lock

« Last post by Roibert on March 14, 2023, 04:52:30 am »

Thanks very much for your reply.

Roberto

25

USB / Should a modern USB device ever have cls/sub/ver in the device descript?

« Last post by Renate on March 11, 2023, 07:32:30 am »

I was always taught that class/subclass/version in a device descriptor is a hangover from USB 1.0 and that certainly any composite device should have zeroes there as that stuff is defined in the interface descriptors. I've generally put zeroes there even for single interfaces.

But I see a case of a (commercial) composite device that is marked ef/02/01 in the device descriptor, that is, DFU.
Moreover, I see that they are using EP0 with interface class out/in transfers.
But obviously a interface class-specific control transfer needs a class.
And that class should come out of the interface referenced by the wIndex in the control request.
In this case, wIndex is 0 and IF0 is an 01/01/20 Audio control v2.0, not DFU.

Am I missing something or is this just bad usage?

26

USB / Re: Window Password or Lock

« Last post by Renate on March 10, 2023, 02:10:28 pm »

AFAIK, Windows doesn't leak the login status unless you explicitly do it yourself.

Ms. Renate

27

USB / Re: Window Password or Lock

« Last post by Roibert on March 10, 2023, 12:51:48 pm »

Thanks Mr Renate for your reply.

I didnt know it was possible to run a script on this events.

Unluck, this cant help me because means to install this script on any computer ,and, this
could be equivalent at install some other app to the computer, some that is not possible
for me.

Thanks again
Roberto

28

USB / Re: Window Password or Lock

« Last post by Renate on March 10, 2023, 10:03:53 am »

You could have scripts run on Windows logon/logoff.
You'd have to make your own USB protocol to inform your device if you're logged on.
Add a Feature Out Report.

gpedit.msc > User Configuration > Windows Settings > Scripts (Logon/Logoff)

29

USB / Window Password or Lock

« Last post by Roibert on March 10, 2023, 05:57:04 am »

Dear Forum.

Have USB protocol some message that inform a USB device if a user insert or not the Password
(at begin of window).

I noted  time ago (my previous post about Window Ibernation), that USB is full active immidiatly
at end of suspension or ibernation  (the SOF flag was detect in the INTERRUPT of my uC  ).

Thanks
Roberto

30

USB / Re: Display as second monitor

« Last post by Roibert on March 09, 2023, 12:21:44 pm »

Thanks very much for your advice, and for all post reply i get from all.

Roberto