3D Robotics created the APM flight control. The platform is completely open source and a great introduction to autonomously operating flight controls. It’s open source legacy has made it a cheap and affordable flight controller.
3D Robotics no longer manufacture the APM flight control. The platform had limitations in it’s hardware. 3D Robotics is now depending on the PixHawk to carry its label. While PixHawk is undoubtedly a better flight controller the APM still remains popular in its clone form. Indeed clone manufacturers have made some valuable improvements to the APM flight control. The APM version 2.6 and 2.7 are currently available from Hobby King , RC Timer and probably from several other online sites. The improvements to the APM flight controller while significant and valuable, include some incompatibility between the 3D Robotics version and the clones. Most significantly the sockets for the communication ports on APM clones use JST connectors while 3D Robotics used the Hirose DF13 connectors. Whilst these connectors are somewhat interchangeable they do pose a few problems. The image right is an adapter cable produced by 3D Robotics that displays both types of connectors. The white connector is the JST while the beige connector is the DF 13. Want both of those connectors will usually fit into their opposing bring sockets sometimes they cause all sorts of connective problems. It’s best if you can avoid using the other brand. If you have a 3D Robotics APM should try and buy 3D Robotics cabling and accessories. If you find it necessary to use and JST connector on the 3D Robotics APM, I suggest trimming the guide lugs on the plug. The guide lugs on the DF 13 don’t go the full length of the socket while the JST connectors do. Second solution is to cut off the JST connector and using one end of DF 13 cable, solder one into the other, one wire at a time. Hobby Kings clone version (APM 2.7), has the useful improvement of not needing to remove a solder bridge from the board when adding an external compass. The only problems here come from poor instructions from the manufacturer. It is a great addition, nonetheless. Many of the new are clones include upgraded components. Improved barometer and better gyros. Firmware can be a problem for these new components. You need to make sure that the firmware updates are made to the APM through Mission Planner. The selection of GPS units for APM modules, is continuing to improve and widen. GPS units Neo-7 and Neo-8 provide improved accuracy and an proved magnetometer. The telemetry adapters cheaper and the power units are in some cases integrated into power distribution boards. The APM is now an older flight control however it offers a huge range of features not available on other currently fashionable systems. There are multiple ground station applications and mobile apps for the APM and PixHawk. The most notable one of these is Mission Planner. All the applications that are currently being adapted from other flight controller have already been written for the APM. APM has wind variety of flight modes, including auto mode that supports completely autonomous flight with waypoint settings and grid flight patterns. Fun modes like Flip, Sport and Drift modes, are great for model club flying or putting on a show at the local park. What isn’t well understood about APM is, you don’t need to use any of the sophisticated flight modes. APM’s Stabilised and Acro modes, are as good or better than many of the new crop. Inbuilt exponentially, softening and raw options for Acro, make APM a fantastic option for FPV or mini quad FC. So while APM is no longer produced by 3DR, the clone crop of APM models is still a valuable option for a multi-rotor and other craft. APM is a multifunction autopilot and not just restricted to multi-rotors. It works on fixed wing aircraft and almost any robot vehicle. You can edit the Arduino code and adapt APM for almost any robot you can imagine. With continued support from clone manufacturers APM should be around for a while yet. by Hotwire