RTK for altitude in 3.4?

ArduCopter Copter 3.4
1

Is there any way to use a Piksi RTK to control the altitude instead of relying on the barometer. In a flat field during auto missions I get a swing of almost 15 ft between waypoints even though Mission Planner continually reports the nominal 20 ft. I’ve noticed the Piksi reports height from reference but there is no way to use it in 3.3.3 that I can find (like ALT_MIX in Plane).

2

You can use GPS as the primary height source: http://ardupilot.org/copter/docs/parameters.html#ek2-alt-source-primary-height-source

3

Perfect, that’s what I was looking for. I followed the Piksi set up guide for interfacing with the Pixhawk but it never said anything about that. I will try the 3.4 beta and see how it works.

Thanks!