On Tue, Dec 20, 2022 at 02:50:17PM +0000, dima.pasechnik@xxxxxxxxxxx wrote: > See https://tech.microbit.org/hardware/ > (choose V2.2X there) > I have nRF52833-QDAA (there is also a different option) Under the "USB Communications" section, that page says: USB classes supported Mass Storage Class (MSC) Communications Device Class (CDC) CMSIS-DAP HID & WinUSB WebUSB CMSIS-DAP HID You already know about the MSC and CDC classes. The other two appear to be versions of a CMSIS-DAP HID protocol, which is clearly not a serial communications protocol since it is HID. So it looks like you aren't missing anything. > here is "details" on the board itself (describing firmware, I suppose) > > # DAPLink Firmware - see https://daplink.io > Build ID: alpha9-189-g5dd23001 (gcc) > Unique ID: 9905360200052833525e24a702a68552000000006e052820 > HIC ID: 6e052820 > Auto Reset: 1 > Automation allowed: 0 > Overflow detection: 0 > Incompatible image detection: 1 > Page erasing: 0 > Daplink Mode: Interface > Interface Version: 0256 > Bootloader Version: 0256 > Git SHA: 5dd23001a7a3199d74870790049d6686e183316c > Local Mods: 0 > USB Interfaces: MSD, CDC, HID, WebUSB Which agrees with the information on the web site. I have no idea what WebUSB is supposed to be. In the lsusb output it doesn't have any resources -- in particular, no endpoints -- so all of its communications must occur over endpoint 0. > Bootloader CRC: 0xa60a7780 > Interface CRC: 0x0bac75fa > Remount count: 0 > URL: https://microbit.org/device/?id=9905&v=0256 The dmesg log in your original message showed you were trying to bind the usb-serial generic driver to interfaces 4 and 5. But interface 4 is the WebUSB thing which, whatever it is, certainly isn't a serial interface. And interface 5 is another HID interface; it calls itself CMSIS-DAP v2. It sounds like an updated form of the other CMSIS-DAP HID interface. It probably would have bound to the HID driver if you hadn't told the usb-serial driver to control it. In short, there's no reason at all to expect the micro:bit board to give rise to a ttyUSB device. Alan Stern
