ESP32 Thing Motion Shield Data Jibberish

Have questions about a SparkFun product or board? This is the place to be.

Moderator: phalanx

Post Reply
jwells
Posts: 9
Joined: Tue Apr 06, 2010 2:25 pm

ESP32 Thing Motion Shield Data Jibberish

Post by jwells » Sat Jan 26, 2019 2:43 pm

My project measures the acceleration of a plastic car pulled by a constant force (Physics experiment for Newton's Second Law). I'm attaching a picture of the car and the data I retrieve from the LSM9DS1 chip. I'm using a stripped down version of the data logging code provided on Sparkfun's hookup guide.

Please note the data appears fine when the car is not moving. The green line represents gravity. It hovers at 1.0g. The red line is the acceleration in the direction of movement. It should read a near-constant value that tracks with theory. However, notice that all three axes go wonky when the car is released. My only conclusion is that vibration of the car is so severe that the values jump around wildly (positive and negative).

I've tried changing the configurable parameters of the chip. I tried sampling at different time intervals. So far, nothing has smoothed out the data. If I suspend the car from a string and spin it around in a circle, I get better data (at least the values aren't jumping from positive to negative).

Does anyone have any insight?

Thanks.
Jeff
Attachments
IMG_1968.jpg
data03.jpg

Post Reply