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Hi all

We have a cheap and nasty RFID reader to scan some old key fobs (125KHz) which works OK but... the problem with it is that it is a HID device which just splatters any data it reads into any writable field on any screen so if the user has a Word document open and active it can scribble all over it.

We only want one application to use the input.
I don't think it is possible to intercept the USB device and channel it to a specific program although that would be the ideal solution...?
Can I use a USB to serial adaptor and get the data via the COMM port instead?
I cant seem to find a 125KHz RFID that is serial anywhere they all seem to be USB.
If the USB to serial adapters work where would the device get its power from? Currently it draws it from the USB connection but I don't think Serial ports provide power; or do they?

Many thanks

What I have tried:

Searched high and low for a desktop serial RFID reader; they are either 1.3GHz or USB only...
Posted
Updated 19-Oct-17 15:04pm

The USB to serial converters (at least the one I know of) work in the opposite direction (they are USB devices, you need a USB host for your RFID device).


Quote:
Searched high and low for a desktop serial RFID reader; they are either 1.3GHz or USB only
However they could possibly behave better than the one you have (for instance they could have dedicated drivers and libraries).
 
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dnibbo 25-Oct-17 10:59am    
Thanks CPallini
I agree, the serial converters are designed to make serial devices USB not the other way around.
The search for a Serial reader goes on...
You're not going to such an adapter. Your "adapter" would have to be smart enough to know that it's connected to a keyboard HID device and how to translate "keystrokes" to serial data.

Your problem is that you're using a "keyboard wedge" scanner. The scanner exposes itself as a keyboard to the bus. If it's that cheap, chances are good your only option is to accept it as keyboard and plan your code accordingly.

Your only reasonable option, if a keyboard wedge isn't going to work, is to get a different scanner and associated tags that work with it. The new scanner would have to expose its interface as either a serial port (serial over USB really is a thing!) or over Ethernet where you can get the data over TCP/IP.
 
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dnibbo 25-Oct-17 11:03am    
Thanks Dave K

Agree that the device I have is not going to be the solution.
Cant really code around it either as the PC will be multi user / multi tasking and another user may have a word doc open etc. so unable to even guarantee which app will intercept the 'keyboard'.
Still searching for a scanner that connects to the serial port or can do the 'serial over USB thing' .... anyone?

Thanks
Dave Kreskowiak 25-Oct-17 11:31am    
The last ones I used we Ethernet-based and expensive as hell.

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