SmartMotion® MEMS Motion Sensors

I am using a MPU 9250 (three axis accelerometer) with an ESP 8266 to perform vibration monitoring on machine.

I am trying to compare vibration results between the Mems (MPU9250) and a PCB ICP piezo accelerometer (model 352C33), but I am finding some divergences, such as max, min and rms acceleration amplitude.

Follow attached one image from the measurement I performed on a industrial machines: (attachement Capturar.PNG)

Note that I am getting +/-50% less amplitude with the Mems sensor, and I can't understand why...

I have a question concerning the self test and the results handles by the main.c source for arm controllers. Concerning the function run_self_test(void) which I see as line 323 in the file [motion_driver_6.12\arm\STM32F4_MD6\Projects\eMD6\User\src] main.c. The function uses HW offset register to calibrate the MPU9250, but it seems in the caluculation of the calibrations it utilizes sensitivity for 1000dps and 16g. In the documentation AN-MPU-9250A-03 rev 1.0 it states that the sensitivity is 250dps and 2g.

Question: is the main.c incorrect in calculating the calibrated offsets?

Hello Folks,

We have a requirement to implement an algorithm to detect “Harsh Acceleration & Sudden Brake” in one of our project. Could anyone guide/suggest in this regard..???

Waiting for earliest & fruitful reply….:):):)

Regards,
Devendra

Hello Folks,

We have a requirement to implement an algorithm to detect "Harsh Acceleration & Sudden Brake" in one of our project. Could anyone guide/suggest in this regard..???

Waiting for earliest & fruitful reply....:):):)

Regards,
Devendra

I am concentrating only on Accelerometer data from MPU9250, I have disabled Gyro and Magneto for faster communication. I am able to capture 177 samples per second (1 sample has 6 bytes). I am targeting to achieve 4KHz sampling rate (means 4000*6 = 24000 bytes per second). I am generating interrupt of 250 microsecond, also i am writing 0 in register 29 bit[3], DLPF will suppose to be bypassed and rate should be 4KHz. In my case it is (177 samples) nowhere corelated with 4KHz sampling Rate.

Hello everyone,

How does MEMS measurement ranges realized in hardware in details?
Does it use:
1. Amplifiers with different gain ratios?
2. ADC with as many bits as need to serve maximal range with minimal resolution?
3. Does different MEMS cells used?
4. Something else.

Thanks
Gene

Hi,
I am interfacing the MPU9250 processor(without the breakout board) on a custom PCB board for a school project. I am using a STM32L496AG chip. I am pretty new to Invisense and would appreciate any help in the form of documentation or advice in order to get started. I am trying to interface using SPI, and haven't found any reliable sources I can refer too.
Any help would be appreciated.

Thanks.

Sidd

what is the purpose of DMP in MPU6050?

Hello.
I have an ICM-20948 Evaluation Board (https://store.invensense.com/Products/Detail/EVICM20948-TDK-InvenSense/597422/) connected through a level shifter (https://www.adafruit.com/product/757) to a nRF52-DK. I have ported the Discovery Board driver to the nRF52 (https://www.invensense.com/developers/software-downloads/#sla_content_35656)

How to use Pass-Through mode in ICM-20948?

Thanks.