Tilt measurement

[georgek]

Hi,

Right now I have been working on another application with the MMA8451Q. I want to get tilt with resolution up to 0.02 degree using only one axis. This accelerometer counts up to 4096 when 1g. But the problem is the maximum speed I could get is about 800 samples per second and make an average of those samples I only could use 10 or 11 of stables bits (bits not affected by noise). It is not good.

Thanks in advance for any advice,

George

[TomasVaverka · Accepted solution]

Hi George,

Did you try to set the LNOISE bit in the CTRL_REG1 register and MODS1 bit in the CTRL_REG2 register to achieve the best results? Both Low Noise and High Resolution modes can be used at the same time for the best noise performance of the data as you can see in Table 4 on page 7 of the AN4075.

There you can also notice that to get the best resolution, you need to have the largest oversampling rate and thus the lowest ODR.

I would also recommend to use at least two axes to get better resolution.

I hope it helps.

Regards,

Tomas

[georgek]

Thank you for these tips Tomas, now it works without any noise!

Best regards,

George