Attitude sensor?

I have a project that's gonna require attitude sensors. I need to sense how much and in what direction the circuit is leaning. Anyone have ideas for inexpensive sensors to accomplish this? I also need to sense motion and direction but that's not as critical as the attitude. I can do the motion with piezo gryo's if necessary although they are not cheap.
Any input would be appreciated.

Joe

Depending on how much deflection from horizontal you need to measure, this could be done as simply as using a joystick upside down with a weight on the end of the shaft. Measure the resistance on the pots, and calculate the attitude. Other alternatives include fluid filled electrolytic sensors that vary resistance between pins, based on how much pin is immersed in the conductive fluid.

Accelerometers (or tilt sensors) can’t tell the difference between motion and tilt as both gravity and motion produce accelerations. Therefore you could probably use something from the Analog Devices range of MEMS range.

Everyone has a different definition of "cheap", although an ADXL311 can be sourced from Digikey for US$8.50 in quantity 1 which seems pretty reasonable. Going this way you could get all your data from a single device.

This is something I will be looking at using shortly but I have not started the final selection process yet, so if you find anything better with lower cost, I'd like to know.

Oh you totally want solid state accelerometers. They don't oscillate, wear out, or have any static threshold errors due to friction. Also light, tiny, and can't get mechanically hung up on other stuff.

ADXL311 is good. ADXL202 is a similar one but also has a digital PWM output which may be easier for your microcontroller to take in.