I recently tried to connect a temperature sensor (http://www.adafruit.com/product/381) to my RasPi via the GPIO, with a 4.7k (2Watt) resistor connecting the power and data (Source: http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/temperature/) as shown below:
I followed the instructions on the Cambridge link, but to no avail (I used the alternative temperature sensor listed on the website). When I type:
It does not show a the temperature sensor, but it merely shows:
Gah! The Pi Cobbler I use is for the Model B, not B+, but the first 26 pins are identical so it works (in case that's relevant).
Thanks for trying to help!
EDIT I also tried connecting a 3V LED to the 3V3 pin (and ground) but it didn't light up!