Here’s a design challenge for you: make a temperature sensor for any computer. If you’re an exceptionally clever smart ass, you’ll probably write some code to report the CPU temps. Others who take the exercise seriously will probably build something with a 1-wire temp sensor, a microcontroller, and all the hardware required to do that.
[Michael] had a better idea. He did it with just two components. One of those components is a USB connector.
The only reason is project could be created is a rather new part from Microchip, the PIC16F1455. This microcontroller doesn’t require a crystal, can do USB without any additional parts, and has an integrated temperature sensor. [Michael] whipped up a project to set up a USB CDC serial device, read the temperature with the ADC (thanks to a very helpful app note), and sends the temperature to a computer once a second.
Despite being built out of only two components, this could actually be a useful device. The PIC is a USB serial device, and this can be used with any computer made in the past 15 or so years. It would hardly take any code at all to read the temperature with another program, and it’s a very inexpensive build. We have to give style points for soldering a microcontroller directly to a USB connector, too.