JBtek Electronic Compass (3-axis Magnetic Field Sensor) GY-271

Arrived on time. Seems to work as intended but I've only had it for a couple days. 4 stars because it is a hard to mount without any brackets on boardData sheet: http://www.adafruit.com/datasheets/HMC5883L_3-Axis_Digital_Compass_IC.pdfArduino Guide: http://www.meccanismocomplesso.org/en/arduino-magnetic-magnetic-magnetometer-hmc5883l/Raspberry Pi Guide : http://blog.bitify.co.uk/2013/11/connecting-and-calibrating-hmc5883l.htmlThe Arduino Guide is written in Wiring while the Raspberry Pi guide is written for PythonGood luck, and keep it simple.

Works as intended and comes with both straight and right-angle pins. The only reason I didn't give it 5 stars is that it does not include the datasheet or example programs mentioned in the description.

does just what is expected

I'm an engineer so accuracy and repeat-ability are the first two things I look for coming out of a sensor. This one is very repeatable. It thinks 050 is 360 every time. But it also thinks around 140 is 180 every time too. It seems too sensitive to movement between its 0 and 180 and way less sensitive to movement between it's 180 degrees and 360 degrees. It's span between 180 and 360 actually cover about 220+ real world degrees.Guess I will go look for something better.

Does not include the promised documentation. I have no idea what to do with this thing. I'd return it but at $6 it's not worth the bother.

Great little package, almost as pictured.....almost....mine has a nice little blank spot with only solder pads where the compass chip SHOULD be! Guess I should have read the reviews.....