SparkFun Forums

[Red Sand]

Hey Groovy People (& you too Shawn H - ha, j/k),

My students will be creating two or more autonomous vehicles capable of completing a course based on the Annual SparkFun Autonomous Vehicle Competition.

After reviewing success stories from Colorado and Ohio events, we have chosen to use dead reckoning as our method of successfully completing the course.

With a very limited budget we'll be using an r/c car for this challenge, and probably using the SparkFun Wheel Encoder Kit to determine distance - unless someone suggests something better and we can afford it

For calculating direction, which, if any, of the following would be better suited for our needs:

* SparkFun Triple Axis Magnetometer Breakout - HMC5883L
SEN-10530 https://www.sparkfun.com/products/10530

* SparkFun Triple Axis Magnetometer Breakout - MAG3110
SEN-12670 https://www.sparkfun.com/products/12670

* SparkFun 6 Degrees of Freedom Breakout - LSM303C
BOB-13303 https://www.sparkfun.com/products/13303


I'm planning on using a 3.3V regulator to control power to whichever one of these items we use

If anyone suggests another device which will be a better choice, then I will appreciate the input

Thank you very much,

RS

[Red Sand]

Here are two photos of a wheel encoder installation - for testing purposes

[jremington]

I've used two of three you cite (HMC5883L and the LSM303C) plus a couple of others, and functionally they are pretty much the same. I doubt there is much difference in sensitivity or accuracy between any of the current generation of magnetometers, so pick one you like.

All magnetometers MUST be calibrated in their final resting place, as the motor magnets and nearby iron will substantially distort the local magnetic field. The best procedure (IMO) is this one: http://sailboatinstruments.blogspot.com ... ation.html

[Red Sand]

Thank you

[Red Sand]

Liz from SparkFun suggested I get the SparkFun 6 Degrees of Freedom Breakout - LSM303C, BOB-13303

So that's what we'll start out with for direction information

Woo hoo!