NUT USB APC BeagleBone

nospam@example.com (Raymond P. Burkholder) — Sun, 28 Jun 2026 01:10:00 +0000

I have an APC Smart UPS 1500 connected via USB cable to a BeagleBone Green running NUT 2.8.1-5 on Linux 6.18.36-bone40. Even on earlier Linux kernels and versions of NUT, during some sort of UPS transition, I would start to get a log full of the these error messages:

usbhid-ups: nut_libusb_get_report: No such device (it may have been disconnected)

In detail:

kernel: musb-hdrc musb-hdrc.1: Babble
kernel: usb 1-1: USB disconnect, device number 15
kernel: usb 1-1.4: USB disconnect, device number 16
kernel: usb 1-1: new high-speed USB device number 17 using musb-hdrc
kernel: usb 1-1: New USB device found, idVendor=1a40, idProduct=0201, bcdDevice= 1.00
kernel: usb 1-1: New USB device strings: Mfr=0, Product=1, SerialNumber=0
kernel: usb 1-1: Product: USB 2.0 Hub [MTT]
kernel: hub 1-1:1.0: USB hub found
kernel: hub 1-1:1.0: 7 ports detected
kernel: usb 1-1.4: new full-speed USB device number 18 using musb-hdrc
kernel: usb 1-1.4: New USB device found, idVendor=051d, idProduct=0003, bcdDevice= 0.01
kernel: usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
kernel: usb 1-1.4: Product: Smart-UPS_1500 FW:UPS 06.0 / ID=1028
kernel: usb 1-1.4: Manufacturer: American Power Conversion
kernel: usb 1-1.4: SerialNumber: unique_number
kernel: hid-generic 0003:051D:0003.0008: hiddev0,hidraw0: USB HID v1.11 Device [American Power Conversion  Smart-UPS_1500 FW:UPS 06.0 / ID=1028] on usb-musb-hdrc.1-1.4/input0
usbhid-ups[31894]: nut_libusb_get_report: No such device (it may have been disconnected)
usbhid-ups[31894]: nut_libusb_get_report: No such device (it may have been disconnected)

For some reason, USB devices 'disconnect' and reconnect. When the device reconnects, a new DeviceID is assigned to the USB device. This breaks the usbhid-ups drivers supplied by NUT the packages. That is, usbhid-ups no longer sees the APC USB device.

One forum article suggested that there is not enough power in the BeagleBone system to propery power a USB connection. The suggested solution is to add a powered USB hub. I gave that a try with no success in eliminating the problem.

To resolve this, I'm not sure if recent versions of the driver fix this, but I used Debian's udev system to sense the device id change and to restart the NUT USB driver.

In /home/debian, which is the default home directory, I created two files and ran 'chmod +x' on each to make them executable. When a USB 'ADD' state is detected, nut.target is restarted to initiate the detection and connection process. When a removal is detected, the service is stopped. The stop does not seem to be reliable, but the restart appears to be reliable enough to get things started again.

$ cat usb_add.sh
#!/usr/bin/env bash

logger "USB state change detected: $1 $2 $3"
echo "$(date) USB state change detected: $1 $2 $3" >> /home/debian/usb-log.txt
systemctl restart nut.target
exit 0

$ cat usb_remove.sh
#!/usr/bin/env bash

logger "USB state change detected: $1 $2"
echo "$(date) USB state change detected: $1 $2" >> /home/debian/usb-log.txt
#systemctl stop nut.target
exit 0

To determine useful attributes I used the following (the first is a shorter result than the second):

udevadm info --name=/dev/bus/usb/001/017 
udevadm info --name=/dev/bus/usb/001/017 --attribute-walk

The rule which invokes these scripts is:

# cat  /etc/udev/rules.d/89-usb-ups-change.rules
SUBSYSTEM=="usb", MODE="0660", ACTION=="add",    ENV{ID_VENDOR_ID}=="051d", ENV{ID_MODEL_ID}=="0003", RUN+="/home/debian/usb_add.sh add '$env{DEVNAME}' '$env{ID_USB_SERIAL}'"
SUBSYSTEM=="usb", MODE="0660", ACTION=="remove", RUN+="/home/debian/usb_remove.sh remove $env{DEVNAME}"

These command variations were suggested to simulate a cable re-connect but did not reliably work. I resorted to physically disconnecting and reconnecting the cable to perform a proper test for tuning and production (using the major:minor usb device manufacturer code):

# major:minor usb device manufacturer code
usbreset 051d:0003
# dev bus id
udevadm test /dev/bus/usb/001/007

Each rule change test required the following to reload the udev rules:

udevadm control --reload-rules

To see what Nut sees:

# nut-scanner -U
Scanning USB bus.
[nutdev1]
        driver = "apc_modbus"
        port = "auto"
        vendorid = "051D"
        productid = "0003"
        product = "Smart-UPS_1500 FW:UPS 06.0 / ID=1028"
        serial = "unique id"
        vendor = "American Power Conversion"
        bus = "001"
        device = "017"
        busport = "002"
        ###NOTMATCHED-YET###bcdDevice = "0001"

A linux command provides a concise device and manufacturer id:

# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 016: ID 050d:0234 Belkin Components F5U234 USB 2.0 4-Port Hub
Bus 001 Device 017: ID 051d:0003 American Power Conversion UPS

Other troubleshooting commands include:

udevadm monitor
This solution for those who might encounter Update 2.7.4 to 2.8.4 CP UPS driver disconnect (nut_libusb_get_report: No such device)

Linux - Copying file to clipboard

nospam@example.com (Raymond P. Burkholder) — Mon, 25 May 2026 02:25:44 +0000

Install tool:

sudo apt install xclip

Perform the copy:

cat filename.base64 | xclip -rmlastnl -selection clipboard

Installing Citrix Workspace on Debian

nospam@example.com (Raymond P. Burkholder) — Sun, 10 May 2026 00:36:22 +0000

On installation, the Citrix Workspace installer will ask for libwebkit2gtk-4.0-37. However, in the latest Debian, libwebkit2gtk-4.1-0 is installed. That package brings in many other packages so there is no practical way to install an earlier version.

The solution to this give the older Debian Bookworm a try where the package is available for installation.

> apt-cache search libwebkit2gtk
libwebkit2gtk-4.0-37 - Web content engine library for GTK
libwebkit2gtk-4.0-dev - Web content engine library for GTK - development files
libwebkit2gtk-4.0-doc - Web content engine library for GTK - documentation
libwebkit2gtk-4.1-0 - Web content engine library for GTK
libwebkit2gtk-4.1-dev - Web content engine library for GTK - development files

To prep for Citrix installation, install the following:

# apt install libwebkit2gtk-4.0-37 libcurl4 libspeexdsp1

Raymond P. Burkholder - Things I Do - Linux

NUT USB APC BeagleBone

Linux - Copying file to clipboard

Installing Citrix Workspace on Debian