There are many libraries (C, Python) out there for reading the TEMPer family of thermometer and hygrometer devices.
Since I own only one device with USB ID 413d:2107 and wanted just simple JSON output, I
wrote yet another program to read from this kind of USB device.
It uses the HIDAPI library as dependency.
On Debian (based):
sudo apt install libhidapi-hidraw0
On Arch:
sudo pacman -S hidapi
Example dmesg output:
[35813.492854] usb 2-1.3: new full-speed USB device number 25 using ehci-pci
[35813.591045] usb 2-1.3: New USB device found, idVendor=413d, idProduct=2107, bcdDevice= 0.00
[35813.591053] usb 2-1.3: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[35813.603164] input: HID 413d:2107 as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.3/2-1.3:1.0/0003:413D:2107.0027/input/input39
[35813.660537] hid-generic 0003:413D:2107.0027: input,hidraw0: USB HID v1.11 Keyboard [HID 413d:2107] on usb-0000:00:1d.0-1.3/input0
[35813.662589] hid-generic 0003:413D:2107.0028: hiddev1,hidraw1: USB HID v1.10 Device [HID 413d:2107] on usb-0000:00:1d.0-1.3/input1
Example lsusb -d 413d:2107 output:
Bus 002 Device 025: ID 413d:2107
Photo of my TEMPer device:
The program is licensed under GPLv3 (local copy).