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By neruneko
#200213
Hello,

first of all: I am an experienced software developer but am in my early stages in learning about sensors.

I just bought a 9DoF Razor IMU board and am currently trying to use it with the standard firmware that came with the board.

Using the standard commands I turned the output from the accelerometer, gyroscope and magnetometer off and turned the output for the Euler Angles on. I also reduced the log rate to 1Hz.

My question is: Should the displayed values not be more or less constant when I let the razor (attached to a wooden board) lie flat on my desk?

Instead of this I get heavily changing values:
2017589, 10.15, 185.94, 325.58
2018588, 10.93, 185.57, 321.59
2019588, 11.68, 185.19, 317.59
2020588, 12.38, 184.78, 313.59
2021587, 13.04, 184.35, 309.59
2022586, 13.62, 183.86, 305.57
2023586, 14.11, 183.39, 301.56
2024586, 14.54, 182.88, 297.53
2025586, 14.90, 182.37, 293.49
2026586, 15.21, 181.85, 289.46
2027584, 15.45, 181.31, 285.41
2028584, 15.59, 180.77, 281.38
2042578, 9.92, 173.95, 225.09
2043577, 9.08, 173.62, 221.10
Has anybody here any ideas what the problem is? Or am I understanding something wrong? Or has one of the sensors just a defect?

Joerg
By jremington
#200216
You should read the comments on the product page. Basically, the DMP firmware in this sensor is useless for most serious applications, unless you are willing to put a lot of work into it. The firmware in the BNO055 module works somewhat better, but is also rather primitive.

A much better approach is to use Arduino compatible RTImulib with one of other the supported sensor sets, and at the very least carefully go through the procedure to calibrate the magnetometer. For an example, see https://forum.pololu.com/t/state-of-the ... or-25/8091