A MEMS chip can be a collection of sensors (temperature, accelerometer (x,y,z), atmospheric pressure, Hall effect sensor (compass), ...) all built into the same chip. In mass production the chip could be relatively inexpensive.
http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/20/35967/01704675.pdf?isnumber=35967&prod=JNL&arnumber=1704675&arSt=+3506&ared=+3508&arAuthor=+Choi%2C+S.%3B++Kim%2C+S.-H.%3B++Yoon%2C+Y.-K.%3B++Allen%2C+M.G. However, an Android shortcut would be to use the GPS sensor and your relative direction of travel to produce a compass bearing over 100 feet of uniform travel. For each model of cell phone the antenna sensitivity changes as you rotate the cell phone about a point. This could potentially be tied in with relative position movement to estimate a compass bearing about a point. But as I said, the lookup table would be different for each model of cell phone. This type of engineering where you take two sensors with low resolution to combine their results to provide greater resolution is called "Sensor Fusion". Basically a cell phone antenna signal does NOT have the same signal profile when you rotate left versus rotate right. This can be capitalized upon to determine the relative bearing of which the compass is facing. Coupled with the cell phone GPS the relative bearing can be referenced to the true bearing. A lookup table can provide a correction factor and thereby produce Magnetic Bearing; vis vi Compass. James Dunn Table of Contents - Similar Insights related to technology applications http://blog.360.yahoo.com/jamesbdunn?p=207 On May 15, 9:23 pm, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: > I have no idea how much a cell phone with a compass costs. I don't see > why it would be expensive if there were enough of a market to micro > machine it like all those tiny mirrors. > Who knows these answers? > > Thanks, > Ed --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Discuss" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/android-discuss?hl=en -~----------~----~----~----~------~----~------~--~---
