hrt_call_init() can be used to initialise (zero) a hrt_call structure
to ensure safe usage. The hrt_call_every() interface calls this
automatically.

hrt_call_delay() can be used to delay a current callout by the given
number of microseconds

after discussion with Leonard these analog on-chip filters should be
at 50Hz

this gives 5MHz SPI bus speed (by asking for 6MHz due to timer
granularity).

Tests with a logic analyser show that the ms5611 is actually more
reliable at 5MHz than lower speeds

this makes logic traces cleaner by zeroing extra bytes written

this allows the software filter to do its job properly

Hotfix Hex Startup

Hex Startup: Set rate of all 8 PWM outputs (6 are not possible because rate can only be changed for channel groups

params not tuned yet, but servos in the right direction

this gives cleaner traces

this allows us to tell if the main loop is running by looking for a
blinking blue LED

this ensures we follow the datasheet requirement of 1MHz for general
registers and up to 20MHz for sensor and int status registers

this allows the bus speed to be changed on the fly by device
drivers. This is needed for the MPU6000

useful for diagnosing issues

missionlib: waypoint yaw fixed

fix off by one in missionlib

Backside update/ python HIL fix