PX4/Firmware — pull request #1458 by julianoes (2014-11-16 03:40:52+00:00)
Title: Fix navigator load

Slow navigator down from 8% CPU to 1-2% by only updating the sensor combined with 50Hz and therefore only running at 50Hz.

Fixes #1457 .

```
Processes: 21 total, 2 running, 19 sleeping
CPU usage: 57.87% tasks, 0.94% sched, 41.20% idle
Uptime: 14.500s total, 5.163s idle

PID COMMAND CPU(ms) CPU(%) USED/STACK PRIO(BASE) STATE
0 Idle Task 5162 41.198 0/ 0 0 ( 0) READY
1 hpwork 233 1.779 604/ 1992 192 (192) w:sig
2 lpwork 101 0.749 668/ 1992 50 ( 50) READY
3 init 1671 0.000 1348/ 2992 100 (100) w:sem
6 nshterm 2 0.000 916/ 1592 70 ( 70) w:sem
133 top 153 2.153 1284/ 1696 100 (100) RUN
56 dataman 57 0.000 772/ 1992 100 (100) w:sem
58 commander 220 0.374 2604/ 3192 215 (215) w:sig
59 commander_low_prio 5 0.000 572/ 2896 50 ( 50) w:sem
61 fmuhil 102 0.936 924/ 1192 100 (100) READY
63 px4io 807 6.273 900/ 1992 240 (240) w:sem
73 mavlink_if0 223 1.498 2004/ 2896 100 (100) READY
74 mavlink_rcv_if0 2 0.000 836/ 2896 175 (175) w:sem
103 sensors_task 710 5.617 1092/ 1992 250 (250) w:sem
109 sdlog2 124 0.655 2084/ 2992 70 ( 70) READY
111 gps 43 0.093 764/ 1496 220 (220) w:sem
115 attitude_estimator_ekf 3162 25.936 13012/13992 250 (250) w:sem
117 position_estimator_inav 392 3.370 4172/ 4992 250 (250) w:sem
119 mc_att_control 699 5.617 1156/ 1992 250 (250) w:sem
124 mc_pos_control 97 0.936 1100/ 1992 250 (250) w:sem
132 navigator 256 1.872 940/ 1992 250 (250) w:sem
```