DMP 101

[deamonata]

I'm currently trying to understand the 6 axis dmp on the mpu-9150. my end application is to communicate with the mpu-9150 from a SiLab C8015F411 microcontroller. I can currently obtain the raw values from the sensor however it would be much more useful if I could obtain heading data. I've been trying to make sense of what the arduino dmp code is doing, however I've not be making much head way. I was wondering if anyone could give me a DMP-101 lesson on how to get it working.

Thanks in advance

 

[Jeff Rowberg]

Unfortunately, the only people who can give you a good idea of how the DMP works work at InvenSense, and they are extremely hesitant to explain it (understandable from a business perspective, but annoying for us). The most complete set of "setup" steps that I have found are the ones in the DMP6 example sketch, which are implemented in the MPU6050_DMP6_MotionApps20.h file that is part of the device code library.

 

This alternative library from GitHub user "Pansenti" is another good reference, specifically for the 9150:

 

https://github.com/Pansenti/MPU9150Lib/blob/master/libraries/MPU9150Lib/MPU9150Lib.h

 

The DMP is a very tightly closed "black box" component for most us; my code in the I2Cdevlib only works by imitating when the eval board does over the I2C bus. Some registers are documented in the datasheet, but the actual DMP binary code block and subsequent configuration commands are not explained there.