The TFD 500
The TFD500 from ELV Elektronik is the successor of the TFD128. It’s a cheap device to electronically log room-temperature and humidity. In predefined intervals and — if running on batteries — independently from the PC, the small device collects the environmental data. Afterwards, this data can be downloaded to the PC and further processed.
Like many other commercial devices, the logger comes with no support for the Linux operating system. If you want to control the TFD500 with Linux, you can find a python-script in source code section (see Github link) to access the data via command line.
Remark: If the TFD500 is connected to the USB-port, no batteries are required since the device will be powered by the PC. However, note that in this case, the logger will measure slightly higher temperatures as the USB-to-serial controller chip will slightly heat up the device.
If you’re looking for a nice alternative Windows software, please visit Vincenz Dreger’s page.
A tip for those buying the kit instead of the fully assembled device: don’t use your expensive electronics cutter for cutting the battery contacts. The contacts are made of spring steel which is very hard and will most likely ruin the cutter. BTDTGTT. Try finding a wire cutter capable of cutting steel wire.