KB / Mouse echo

[ivof]

Windows (and probably other OS's) support multiple KB and Mouse.

If there was a "Keyboard.listen()" it would be possible to parse the output from the attached keyboard.

I think that it would be very useful to transparently interact with the boards.

Same but probably less useful for "Mouse.read()"

 

[PaulStoffregen]

If there was a "Keyboard.listen()" it would be possible to parse the output from the attached keyboard.

No. USB does not work that way.

Even though it's called universal serial "bus", devices like Teensy do not have any opportunity to observe the device-to-host communication of other devices. Even when connected to the same USB hub, the data transmitted by any device is send only to the host. Other devices can't hear it.

However, the host-to-device communication is broadcast in some cases to all downstream devices. But keyboards and mice are almost always low-speed (1.5 Mbit/sec) devices. With USB 2.0 hubs, the host doesn't communication directly with those devices when they're connected to hubs. Instead the host communicates (at 480 Mbit) with a "transaction translator" inside the hub which does the slow communication with the keyboard on the host's behalf. USB is a complicated protocol....

But the short answer is no, Teensy can't see the communication from other USB devices which happen to be connected to the same USB host.