Overview

Driver for Freescale MPL115A1 and MPL115A2 pressure sensors.

Resources

All correct at time of writing, but as always, manufacturers love to move things around on their website.

Web page

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPL115A

Datasheet

MPL115A1 (PDF)
MPL115A2 (PDF)

Test hardware

This code has been tested using a SparkFun MPL115A1 breakout:

https://www.sparkfun.com/products/9721

This was wired to a CoreProto and plugged into a SenseCore:

http://soldercore.com/products/sensecore/

And finally installed on a SolderCore:

http://soldercore.com/products/soldercore/

Notes

The polynomial used for pressure compensation is based on the Revision 6 LPC115A1 datasheet, published 10/2011:

• Pcomp = a0 + (b1 + c12 × Tadc) × Padc + b2 × Tadc

The Revision 4 MPL115A1 datasheet, published 03/2010, uses a slightly different method with additional coefficients:

• Pcomp = a0 + (b1 + c11×Padc + c12×Tadc) × Padc + (b2 + c22×Tadc) × Tadc

Freescale note that c11 and c22 were always set to zero in MPL115A devices and, therefore, the Revision 6 calculation is preferred (and equivalent in practice).

API Summary

Macros
MPL115A2_I2C_ADDRESS	MPL115A2 8-bit I2C address
Initialization
mpl115a_initialize_i2c	Initialize sensor on I2C bus
mpl115a_initialize_spi	Initialize sensor on SPI interface