原文
ArduCopter 2.5.5 release.<br>A patch release which has the following improvements over 2.5.4:
1. MPU6000 accelerometer scaling fix (affected 3dr APM2s shipped from early May)
2. "Retro Loiter" by Adam Rivera (uses ground speed directly from GPS instead of calculating from lon/lat position)
3. Optical flow support for APM2
4. bug fix for "need to press reset before arming motors"