The EnvStick is cheap, homemade temperature sensor that plugs into a USB port. It provides a simple way to collect a room’s ambient temperature. I made it for fun.
- Temp sensor (+/- .5 deg C)
- USB 2.0
- Windows/Linux software
- Poll up to 100 times/minute- In-circuit programming- Only 11 components- Indicator LED
|The EnvStick shows up as a serial port – a COM port on Windows boxes. Here you can see the typical output (on a program like Hyperterminal) – it waits a specified number of seconds, spits out a temperature reading, and starts waiting again. If you press “p”, you can set the number of seconds in between each temperature reading.|
|On the right are some of the initial EnvStick attempts. It took me a couple tries to get a board that worked without lots of manual “fixes”.|
|Here’s the schematic. Click for a larger version.|
|I got these boards made by Batchpcb.com. They are my first boards with SMD components on both sides. Click for larger versions.
|Thanks to the FT232RL USB<->Serial chip, the EnvStick only needs 11 components:
Plus, the board costs about a buck from batchpcb.com. What a deal!
|A pictures of the first working EnvStick:|
|Here are the Eagle and Gerber files, if you want to make your own boards: