MPU-9150 magnetometer problem

[Spitfire1.2]

Hi everyone!

 

 

  I am making a  3 axis camera gimbal for my bachelor thesis, and I'm using an Avr(Atmega32) with two MPU-9150 modules.

 

 

I get correct values from the accelerometer and gyro, but I am facing problems with the compass.

 

• I switch the mpu to pass-through mode by writing "1" to I2C_BYPASS_EN bit on the INT_PIN_CFG register(55 dec).
• I disable "master-mode"  by writing "0" to I2C_MST_EN pin on the USER_CTRL register(106 dec).
• I read the Device ID address(0x00) of the compass and I get "48H" which is correct.
• I set the magnetometer to "single measurement mode" and I start polling the ST_1 register(0x02h), when the DATA_READY bit is "1", I start reading the measurement data.

 

The problem is that the data ready bit never turns to "1" and If I start reading the magnetometer data without polling the ST_1 reg, all I get is "0" for each axis.

 

 

 I also tried switching the ak8975 to "fuse mode" in order to write into a ASA register a random number so I can read it later, but I still got "0".

 

Any Ideas?

 

thanks for reading!(and sorry for my bad English....).
 

 

 

 

 

[singh85]

Were you able to resolve this. We are facing same issue with magnetometer.