Read nRF52840's MAC address across usb or serial tty?

[Matthew C Clark]

Is there a way to read the mac address from the serial tty of an nRF52840?  I have multiple dongles programmed with the BLE sniffer (nrf_sniffer_for_bluetooth_le_4.1.0) and am trying to map the HW ID of the device to the MAC printed on the dongle:

$ls /dev/serial/by-id/*
lrwxrwxrwx 1 root root 13 Jun 7 12:19 usb-ZEPHYR_nRF_Sniffer_for_Bluetooth_LE_5F88E7362DA8XXXX-if00 -> ../../ttyACM0

lrwxrwxrwx 1 root root 13 Jun 7 12:19 usb-ZEPHYR_nRF_Sniffer_for_Bluetooth_LE_86CA22D6DF10XXXX-if00 -> ../../ttyACM1

I don't have a JLink attached to it, so I can't use nrfjprog to read the memory and nothing under /sys/class/tty/ttyACM[0|1] shows any mac related info.    This is through an Ubuntu 20.04 machine. 

[Kenneth]

Not aware of any way you can do this (or get the mac address), but you may look into using the 'lsbusb -v' command that possibly can help:

lsbusb -v
Bus 001 Device 016: ID 1915:522a Nordic Semiconductor ASA nRF Sniffer for Bluetooth LE
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  idVendor           0x1915 Nordic Semiconductor ASA
  idProduct          0x522a
  bcdDevice            2.04
  iManufacturer           1 ZEPHYR
  iProduct                2 nRF Sniffer for Bluetooth LE
  iSerial                 3 C2E15977A9D11709
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x004b
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xc0
      Self Powered
    MaxPower              100mA
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface         0
      bInterfaceCount         2
      bFunctionClass          2 Communications
      bFunctionSubClass       2 Abstract (modem)
      bFunctionProtocol       0
      iFunction               0
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass      2 Abstract (modem)
      bInterfaceProtocol      0
      iInterface              0
      CDC Header:
        bcdCDC               1.10
      CDC Call Management:
        bmCapabilities       0x02
          use DataInterface
        bDataInterface          1
      CDC ACM:
        bmCapabilities       0x02
          line coding and serial state
      CDC Union:
        bMasterInterface        0
        bSlaveInterface         1
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0010  1x 16 bytes
        bInterval              10
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
Device Status:     0x0001
  Self Powered

Best regards,
Kenneth

[Matthew C Clark]

Sadly, nothing in lsusb shows me the MAC of the device.  I also examined by probing under /sys/class.  I'd be fine if there were a C or Python program I could run that could pull the MAC off the serial connection.

[Kenneth]

I don't think you can find the MAC address no, but can't you use a different identifier to know this is the nRF sniffer dongle?

I don't understand why you need the MAC address in specific, this is a BLE sniffer in any case, so the MAC address of the sniffer should not be important here.

Best regards,
Kenneth

[Matthew C Clark]

The project I'm doing this for has multiple sniffer devices and wants to know which one gets what MAC at what orientation (say left or right).  But unlike the DK, which populates with the HW ID stamped on it, making for easy identification, the dongles have MAC printed, but no HW ID, so there's a disconnect.  It makes it a bit of a pain in the butt and I was hoping for some programatic way of identifying them rather than manually plugging in each dongle and copying the HW ID and its MAC into some spreadsheet.

[Sigurd Hellesvik]

Hi

Kenneth is on vacation, so I will answer this time.

As Kenneth say, you can get a device ID but no MAC from the dongle from the connection, as far as I know.
So the solutions I can think of are:

• Create a spreadsheet as you suggest
• Read the ID from each dongle, and mark them physically, by tape or something.

Regards,
Sigurd Hellesvik

[Matthew C Clark]

Thanks, Sigurd.  That's pretty much what we've been forced to do.