This post is a quick introduction to get an MPU9250 gyroscope, accelerometer, and compass module (so called 9 axis) connected and talking to an Arduino. I’m using a 5V Arduino Nano, because the description of this module says that it is 5V tolerant.
Markings on chip is: MP92 / W864A1 / 1410
The library I used is one included in the Arduino IDE Library manager. When I searched for 9250 there were couple of different ones, but the one I chose was called “SparkFun MPU-9250 9 DOF IMU Breakout”, version 1.0.
I connected it in the following way:
I then tried the included example from the library, called “MPU9250BasicAHRS”, which you can find in the File->Examples menu in the Arduino IDE after installing the library.
After uploading this example, I got the following output on the Serial console:
MPU9250 I AM 73 I should be 71
Could not connect to MPU9250: 0x73
After doing a bit of research, it looks like the chip on this module might in fact be a MPU9255 and not a MPU9250.
According to the register map datasheet for the MPU9250, register 117 should contain the value 0x71 for WHO_AM_I
And according the register map datasheet for the MPU9255, register 117 contains the value 0x73 for WHO_AM_I
These two chips are very similar and after replacing 0x71 with 0x73 in the example sketch, it worked:
Output on Serial:
rate = 225.58 Hz
ax = -41.32 ay = -77.21 az = 908.75 mg
gx = 0.18 gy = -0.08 gz = -0.07 deg/s
mx = -363 my = 282 mz = -677 mG
q0 = 0.88 qx = -0.05 qy = -0.00 qz = 0.48
Yaw, Pitch, Roll: 49.04, 2.53, -4.83