WebUSB support

[larsgk]

It could be a nice extension to the USB libs if we could have WebUSB support for direct communication with hosted web apps (in chrome dev for now).

arduino code: https://github.com/webusb/arduino/blob/gh-pages/library/WebUSB/WebUSB.cpp

WebUSB: https://wicg.github.io/webusb/

[ciarmcom]

ARM Internal Ref: IOTMORF-214

[larsgk]

Looking at the USBDevice code after some years, I see that not much has changed in general. Maybe it would be a good idea - besides the WebUSB thing - to consider a few more improvements:

• Getting --usb to work with the mbed-cli build (not working for me atm - (using GCC_ARM/KL25Z), don't know if other setups work bettter)
• Allow setting PnP elements like manufacturer, serial, etc.
• Better support for bulk sending/receiving (uint8_t buffers)
• Solid support for connect/disconnect/reconnect - and no halts/panics if trying to send while nothing is connected
• Allow adding custom USB headers (WebUSB would be one) - for e.g. composite/hybrid USB device functionality.

(I'll make some separate issues for these)

[larsgk]

Any news on this?

[larsgk]

Actually - I just saw this from @devanlai (will try it out): https://developer.mbed.org/users/devanlai/code/USBDevice_STM32F103/