iphone - Gyro CMAttitude pitch, roll and yaw angle problems -

i have problem getting pitch, roll , yaw angles cmattitude class.

first, did normal gyro using 'cmmotionmanager' class , atributes x,y,z , worked fine. then, tried use cmattitude "absolute angles", doesn't work because seems not updating data. angles 0 (but isn't errors or warnings)

i have searched lot in stackoverflow, , used solutions find, have same problem. here's code:

- (void)viewdidload {   [super viewdidload]; // additional setup after loading view, typically nib.    motionmanager = [[cmmotionmanager alloc] init];    cmdevicemotion *devicemotion = motionmanager.devicemotion;   cmattitude *attitude = devicemotion.attitude;   referenceattitude   = attitude;    [motionmanager startgyroupdates];    timer = [nstimer scheduledtimerwithtimeinterval:1/30.0                                          target:self                                        selector:@selector(dogyroupdate)                                        userinfo:nil                                         repeats:yes]; }  -(void)dogyroupdate {    //cambia el frame de referencia   [motionmanager.devicemotion.attitude multiplybyinverseofattitude: referenceattitude];    double rrotation = motionmanager.devicemotion.attitude.roll*180/m_pi;   double protation = motionmanager.devicemotion.attitude.pitch*180/m_pi;   double yrotation = motionmanager.devicemotion.attitude.yaw*180/m_pi;  nsstring *mystring = [nsstring stringwithformat:@"%f",rrotation]; self.angyaw.text = mystring;  mystring = [nsstring stringwithformat:@"%f",protation]; self.angpitch.text = mystring;  mystring = [nsstring stringwithformat:@"%f",yrotation]; self.angroll.text = mystring;  } 

thanks lot! :d

motionmanager has 4 modes: accelerometer, gyroscope, magnetometer , device motion.

depending on 1 need, need start appropriate mode: startaccelerometerupdates, startgyroupdates, startmagnetometerupdates or startdevicemotionupdates.

you starting startgyroupdates reading devicemotion property. in case gyrodata available.

do instead , getting devicemotion data:

[motionmanager startdevicemotionupdates];