[libhid-discuss] Still can't interrupt_read() properly

[Peter Stuge]

Marian Aldenhoevel wrote:
> I have since learned that it is available with a simple serial
> interface as well and the vendor choose to USBize it as a HID with
> lots of crud

If this IS indeed a Human Interface Device the vendor has actually
gotten the most difficult part of USB right; namely the device
descriptors! If it is not a HID then the Vendor was likely lazy and
used HID because it behaves a lot like a serial port in Windows.


> instead of just adding a serial-USB-Converter and keeping the API.

This is the worst possible way to introduce USB into a product.
Please don't encourage anyone to use this method.


> Ah, well, what's wrong with days and days of experimenting...

The fact is that USB is not a simple serial signal like RS-232, and
many assume that it is just that simple, but with power, when they
first start looking at USB.

In fact, USB is a bus with several layers of protocol that needs to
be understood properly before a good, standards-compliant,
implementation can be made. It is not a trivial specification but it
is fairly readable, and the protocol is well thought-out.


That said, reverse engineering a misbehaving device is never fun when
you just want to get on with using it.


//Peter