3

I was following the Coral Dev Board get started guide - Get started with the Dev Board (https://coral.withgoogle.com/docs/dev-board/get-started/). Everything worked fine until to the step - Connect to the board's shell via MDT. I've waited about 5 minutes until the flashing to complete, and the terminal prompt returned to me, then I tried the command:

mdt devices

The terminal returns nothing. Unlike the guide says it supposes to return my board hostname and IP address. I've checked the USB-C OTG and USB-C power cable, they are all connected well.

I've also tried this solution: https://superuser.com/questions/1452786/coral-dev-board-not-recongized-on-mdt-shell. I went to Network under System Preferences, and clicked "+" icon, but I couldn't find the mendel device.

I'm using Macbook Pro running on macOS Catalina. The fastboot and mdt commands are both working.

Novus
  • 791
  • 8
  • 13

5 Answers5

6

I just found a solution:

Just plug micro-B USB cable, then run:

screen /dev/cu.SLAB_USBtoUART 115200

If it shows blank, wait a couple seconds, then plug usb-c power cable, the system of the dev board will start loading, the login prompt will come out. After I logged in, I plugged the usb-c cable into data port(keep the micro-B USB cable in at the same time), then run:

mdt devices or mdt shell

This solution works for me only when I have turned on the wifi of the dev board and connect it to the same wifi network. If you want to turn on the wifi network of coral dev board, run the command on screen terminal:

nmtui

The Network Manager TUI prompt will come out then you can connect to your wifi network.

Novus
  • 791
  • 8
  • 13
4

It's a problem on macOS Catalina. It doesn't "see" USB connection as a network connection and as such it is impossible to connect to Coral Dev Board. I have the same issue, but I tried with another MAC with older macOS and it worked just fine. Now, I don't have yet the solution, but at least we all know the problem ;-) Regards, Rui

Rui Bras Fernandes
  • 77
  • 7
  • Hi Rui, thanks for keeping other up to date with this issue, we are still looking for a solution for the new MAC update. – Nam Vu Oct 28 '19 at 13:47
  • btw, have you tried what is suggested by Novus below? – Nam Vu Oct 29 '19 at 15:34
  • the bellow solution didn't work for me ... I can connect to console with no issues, I just can't get mdt devices to work in Catalina OS. – Rui Bras Fernandes Nov 28 '19 at 07:45
  • Any movement on getting this to work with Catalina? I tried connecting the ethernet cable and the mdt device command showed the device and an IP address. Followed by the message "it looks like you are connecting to a device that is not connected via USB. Cowardly refusing to attempt to push key to a public machine". Thinking about connecting to a linux workstation instead of MacOS Catalina. – JerryKur Apr 10 '20 at 23:26
4

First check the that the device is detected by running dmesg command. Normally you should see something like this

$ dmesg
...
[107834.681816] usb 2-3: new high-speed USB device number 3 using xhci_hcd
[107834.845073] usb 2-3: New USB device found, idVendor=18d1, idProduct=9304, bcdDevice= 4.19
[107834.845077] usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[107834.845079] usb 2-3: Product: Mendel
[107834.845081] usb 2-3: Manufacturer: Google,LLC
[107834.845083] usb 2-3: SerialNumber: bored-horse
[107834.985296] cdc_acm 2-3:1.0: ttyACM0: USB ACM device
[107834.986069] usbcore: registered new interface driver cdc_acm
[107834.986070] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
[107835.005045] cdc_ether 2-3:1.2 usb0: register 'cdc_ether' at usb-0000:06:00.3-3, CDC Ethernet Device, aa:9f:04:54:dc:45
[107835.005124] usbcore: registered new interface driver cdc_ether
[107835.019787] cdc_ether 2-3:1.2 enxaa9f0454dc45: renamed from usb0
[107897.336866] IPv6: MLD: clamping QRV from 1 to 2!
[107956.344960] usb 2-3: USB disconnect, device number 3
[107956.345357] cdc_ether 2-3:1.2 enxaa9f0454dc45: unregister 'cdc_ether' usb-0000:06:00.3-3, CDC Ethernet Device
...

After that, check your network interfaces using ip command

$ ip link

Then look for the one with the one with the same MAC address as the one that appears in the logs of dmesg. Once you find it, run this command to assign an IP address

$ sudo dhclient <name of the network interface of coral dev board>

Now you should see an IP assigned to the interface.

$ ip a

After that, run mdt devices and you should see the dev board connected.

$ mdt devices
bored-horse             (192.168.100.2)
pythops
  • 41
  • 1
  • This worked great. Seems like poor documentation on Google's part to not include something like this in the troubleshooting steps... – Alex Wulff Jan 26 '22 at 01:51
0

I had the same problem in Debian (Buster). I was able to follow all the steps to connect and flash the device until 'mdt shell' and I would receive a 'Unable to find any devices on your local network segment' message.

Opening the network settings and enabling 'USB' as a network interface worked for me.

After connecting to the Coral Dev Board the first time and exchanging private keys, I unplugged the USB cable. After that, my computer was offline until I re-enabled the ethernet connection. It seems that enabling the USB network disabled the ethernet. At that point, mdt shell was able to connect via the ethernet network.

Josh
  • 1
  • 2
0

So I've just spent most of the afternoon with this issue. After I downgraded the OS to Chef it seemed to work fine as the USB device (OTG port) would initialize on boot and then the SSH key could be pushed through. However, with the latest OS (Eagle) this was not the case.

The fix was simple:

  • Remove the USB C OTG port cable from the board
  • Reboot the Coral board
  • Wait for boot sequence to complete
  • Connect the USB C OTG port cable to the board
  • Run "mdt shell"

key is pushed through!

Now I can set up the WiFi or connect Ethernet and remove that cable once again and now I can freely call mdt shell and it connects every time.

Cameron H
  • 1