Some time ago I had a problem with availability of the accelerometers for my inertial module. One of key features of my on-board computer is modular construction, allowing to be independent from the sensor availability. If one module is not available, another can be used instead. Problem was, because I had not another inertial module, but had newly acquired ITG-3200 gyroscope and new, not tested yet magnetometer MMC3140.
I decided to build another inertial module based on cheap sensors with digital I2C interface. Added to it LIS302DLH accelerometer. It could be enough, but sensors occupied only small part of area on my standard module, so decided to add some more sensors, all on I2C bus. First was added pressure sensor BMP085 and for comparision with it HP03S and MS5803. Also added accelerometer BMA180. The board start to be full. Most of the sensors are new to me, so always is possibility to make an error on PCB, so this module since begining is experimental. In this version will not be manufactured in volumes higher then initial 10 pcs. Next versions will be reduced to necessary amount of sensors.
There is a view of assembled module. Only MS5803 sensor is not present yet, but soon should be added and tested.
Schematic of the module: http://www.pitlab.com/autopitlot/sch/mod_DigAllinOne00.pdf
I made some tests of the sensors and published it here: Test of pressure sensors