I have a 3.3VCC M.2 nRF52840 device connected to the USB lines on the M.2 B-key interface.
USB2_HOST2_DM << >> HOST_DM1
USB2_HOST2_DP << >> HOST_DP1
However it doesn’t show up on the E25. I also have a the same device laid on a PCB with USB A footprint that does show up as ttyACM0 when plugged into to the full size USB port.
rock@radxa-e25:~$ sudo journalctl -f
Feb 20 12:01:37 radxa-e25 kernel: usb 5-1: new full-speed USB device number 2 using xhci-hcd
Feb 20 12:01:37 radxa-e25 kernel: usb 5-1: New USB device found, idVendor=cafe, idProduct=4001, bcdDevice= 1.00
Feb 20 12:01:37 radxa-e25 kernel: usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Feb 20 12:01:37 radxa-e25 kernel: usb 5-1: Product: MynRfDevice
Feb 20 12:01:37 radxa-e25 kernel: usb 5-1: Manufacturer: ForumUser
Feb 20 12:01:37 radxa-e25 kernel: usb 5-1: SerialNumber: 12345678
Feb 20 12:01:37 radxa-e25 kernel: cdc_acm 5-1:1.0: ttyACM0: USB ACM device
Feb 20 12:01:37 radxa-e25 kernel: usbcore: registered new interface driver cdc_acm
Feb 20 12:01:37 radxa-e25 kernel: cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
rock@radxa-e25:~$ lsusb
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 002: ID cafe:4001 MyRfDevice << pluged in to the USB A port
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Any suggestions welcome.
Thanks