I just finished developing my USB temperature logger and shot a video showing how it works. Here are the key figures:
- Up to two months of logging with a single coin cell battery.
- 30 000 timestamped temperature measurements.
- Logging period from every 5 seconds to every 24 hours.
- 0.5°C accuracy, 0.06°C resolution.
- No driver, no software and no admin rights needed!
- Compatible with any computer with USB port.
- Automatic time synchronization with the computer.
- Low cost design.
When plugged to a computer’s USB port, the logger appears as a normal USB drive. The temperature logging period is changed by editing a config.txt file. When this file is saved, the logger reads the periodicity (in seconds), synchronizes its clock to the computer’s date and time and starts to flash the LED to indicate it’s ready to log. Once removed from USB, the logging is started by pushing the button (the LED blinks three times). For every temperature measurement, the LED flashes.
Once plugged back to USB, the file DATA.CSV will contain all the temperature measurements and the corresponding date and time, TAB separated.
A future development could include a Li-Ion USB rechargeable battery, battery life monitoring, low power – long period logging mode.
If you’re interested by this project, don’t hesitate to contact me. Share if you like it!