Monday, July 20, 2015

Pixhawk Versus APM Comparison Review

This blog entry compares two flight controllers from the Ardupilot 3DR-Open-Source stream: the generic APM 2.X controller and the Pixhawk.  I am an intermediate multirotor builder and flyer, so this comparison will focus on functionality and useability, not on advanced features.  Also, this review is based on my experience with 5 different APM modules (none sourced from 3DR) in three different physical forms: standard, mini, and micro (also called mini by some) sourced from Hobbyking and generic Chinese manufacturers.  The Pixhawk is available from multiple domestic and Chinese sources and you should check the reviews to make sure you are getting one with decent build quality.  Each was used with corresponding GPS/Compass units from the same manufacturers.  I built three different quadcopters and used them with different controllers.

Feature/CharacteristicGeneric APM 2.X3DR PixhawkComment
Size/WeightSmallLargerAPM is available in 35x35x5 mm board.  Pixhawk is 81x50x16 mm
CostLowHigher, about 4XAPM with GPS ~$65
QualityVariableBetterInspect a generic APM after you get it for poor soldering, loose USB..
SupportGoodGoodThe best support is from peers on DIYdrones and APM forums
Flight StabilityGoodGoodThis is my experience with a well setup APM and Pixhawk, your experience may vary
AccuracyGoodBetterIt does depend on your GPS and its accuracy.  Pixhawk has a more powerful processor and more memory
Onboard indicatorsPoorGoodPixhawk has multiple LEDs and tones to tell you status, APM has a few LEDs
Ease of SetupModerateModerateMore components to interconnect on Pixhawk, but well documented. Cables and connectors often an issue with APM and documentation must be found on the Internet.
Ability to fly autonomous missionsYesYes
Mission Planner Ground Station CompatibilityYesYes
Flight logging CapabilityGoodBetterPixhawk logs more information and has a microSD for storage. APM has limited storage of most important variables.
UpgradeabilityNoneYesAPM code is now frozen to my knowledge, but Pixhawk software with improvements still being released
Debugging difficultyGoodMore difficultAPMs seem to always work, Pixhawk is more finicky about ESCs, setup, etc.

Overall, both controllers are excellent and have worked well for me.  The APM is a better fit for small quadcopters and is probably better for the beginner builder due to its simpler setup and low cost.  The Pixhawk is very good but it takes more time to set up and it is likely higher quality and performance, so it works well in larger camera quadcopters and similar expensive vehicles.

APM equipped SK450 "Dead Cat" Quadcopter
S500 Quadcopter with Pixhawk


  1. What are differences in terms of performance specs like RTL,Stable Mode etc!
    And do you think pixhawk clone boards will perform eually to the original one!

    1. I use both the original pixhawk from 3DR and a Holybro clone. Both are equal in terms of performance, even to the point of having the same faults like difficulty calibrating the ESC endpoints. The APM clones are similar in performance for basic capabilities like RTL, loiter, etc but they cannot take up to date firmware, cannot handle more advanced commands, etc. At this point, given the price of Pixhawk clones and the reduction in size, I would recommend a pixhawk clone over apm.