The EnvStick is cheap, homemade temperature sensor that plugs into a USB port. It provides a simple way to collect a roomβs ambient temperature. I made it for fun.
EnvStick Features:
β Temp sensor (+/- .5 deg C)
β USB 2.0
β Windows/Linux software
β Poll up to 100 times/minuteβ In-circuit programmingβ Only 11 componentsβ Indicator LED
The EnvStick shows up as a serial port β a COM port on Windows boxes. Here you can see the typical output (on a program like Hyperterminal) β it waits a specified number of seconds, spits out a temperature reading, and starts waiting again. If you press βpβ, 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 βfixesβ.
Hereβs the schematic. Click for a larger version.
For more detail: EnvStick USB Temperature Sensor using PIC12F683