Reading pedometer data from MPU6500

I ported Embedded Motion Driver 5.1.2 to use with an ARM microcontroller and was able to read quaternions from the FIFO. But when I try to read pedometer data using dmp_get_pedo_stepcount() and dmp_get_pedo_walktime() I couln't read a proper value.
The value returned by the functions are zero, so I suppose the program managed to read the registers. The problem is the output parameters are also zero and no matter how I move the MPU6500 the value does not change.
So is there a way to somehow "turn on" the pedometer function (the motion driver says this function is always on, so I did not include its masking value when I initialize the feature with dmp_enable_feature), or am I reading the wrong data?
Thank you : :D D