accelerometer for tilt sensor

[mruckstuhl]

I am looking to replace a 2-axis accelerometer (from a different vendor) with a 3-axis one, primarily used as an inclinometer. I need 0.1 degree resolution or better between +/- 20 degrees, but the third axis gives me positional flexibility for the unit. I like the resolution advertised for the MMA8451Q and the FXLS8471Q, but aside from I2C vs SPI, I haven't figured out the difference between them.

Does anyone have recommendations for a tilt sensor, including things to look for?

[TomasVaverka · Accepted solution]

Hello,

You are right, the main difference is that the FXLS8471Q includes the SPI interface. There are some additional differences though, for instance the FXLS8471Q incorporates an acceleration vector-magnitude detection function (more info can be found in the AN4692), has a hardware reset pin (RST) and two address selection inputs (SA0 and SA1) that allow assignment of four unique I²C slave addresses.

In terms of noise and temperature performance, both accelerometers are almost identical and meet your resolution requirements. To achieve the highest possible resolution, use the lowest possible ODR and set the LNOISE bit in the CTRL_REG1 register and MODS1 bit in the CTRL_REG2 register.

I hope it helps.

Regards,

Tomas

PS: If my answer solves your question, please mark it as "Correct" or “Helpful”. Thank you.