Anyone experienced DMP?

[pico]

Hi folks,

 

Im planning to use DMP functionality of MPU6050 but not ordered it yet.

I have some questions to who had an experience on DMP.

 

1) Does INT pin of the MPU mean "Hey, i have calculated the Quaternions and put it to the FIFO. Come and get it"

           in this case, is it really required to poll fifo bytes? (assuming the mcu is really fast to read fifo lightspeed, no overflow)

 

2) What is the purpose of setting MPU slave adress to its self address? Does it connects to itself or something?

           Im planning to have aux magnetometer readings, with or without master-mode. Is it possible? Anyone tried?

 

3) Is it possible to use 4G, 8G readings with DMP?

           Under one of the topics, it is said that changing full-scale while DMP is running is making its output incorrect. So is it possible to set a desired full-scale value for accel and gyro, before enabling DMP?

 

Any little help will be appreciated.

Thanks!

[pico]

Any comments?

I really need to clarify theese aspects.

[Egholm]

Any comments?

I really need to clarify theese aspects.

 

No. After googling this, I found the following comment inside InvenSense's "mllite_test.c" example code provided with eMPL 6.1:

 

"DMP sensor fusion works only with gyro at +-2000dps and accel +-2G"

[mllite_test.c, l. 967]

[nerdoug]

(I'm assuming you're using Arduino processors, which may not be true)

regarding your 1): Suggest you look at sample code at 

https://github.com/jrowberg/i2cdevlib/blob/master/Arduino/MPU6050/examples/MPU6050_DMP6/MPU6050_DMP6.ino

and in particular, the routine mpu.dmpGetCurrentFIFOPacket(fifoBuffer) 

which greatly simplifies the work needed to read from the fifo.

Also suggest verifying your libraries have this fix:

https://github.com/jrowberg/i2cdevlib/blob/master/Arduino/MPU6050/MPU6050.cpp

 Cheers, Nerdoug.