Hologram Nova U201 RP4B Reboot Issues

Hello,

I am having some issues with getting the Hologram Nova to function after a system reboot. I am using the Hologram Nova U201 with a Raspberry Pi 4 with a 3A power supply.

When I plug the device into the Pi after it has been booted, everything works fine. Running sudo hologram network connect works and brings up ppp0, and I see U-Blox AG LISA-U2 after running lsusb

If I reboot the pi, either by running sudo reboot or by physically power cycling the device, running sudo hologram network connect returns ERROR: Modem not detected and it also the usb device doesn’t come up after running lsusb

Unplugging and replugging the Nova into the Pi will correct the error, and everything will come up.

I am searching into methods to cycle the power on the usb port or refresh it in some way, but haven’t had much luck on this front yet.

Any help here would be much appreciated. I have done extensive searching online and most of the time these issues come down to a power problem, but with the power supply I am using I just think that isn’t the case, especially since it works every time after I unplug and replug the device.

Just following up on my original post. I found a solution. Still having inconsistency with the usb device appearing on bootup. I found that waiting to call the connect command helped but did not work 100% of the time.

After boot and before calling the connect command, the USB hub of the Pi 4 can be reset. To do this I used the usbreset C program located here: https://gist.github.com/x2q/5124616

To compile: gcc -o usbreset usbreset.c
To set permissions: chmod +x usbreset
To use the program to reset hub: sudo usbreset 001/002

Hope this helps anyone having similar issues.

T

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