If you want to get started flying drones, a web search will reveal various models in a wide range of prices and capabilities. Naturally, the more money you pay, the better drone you can get — but what if you want an autonomous quadcopter that costs under $200?
For that, you’ll need to start hacking, and if you’re wondering where to start the process, then this article by Mukut Mukherjee is a great resource. In it, Mukherjee outlines what kind of frame might be appropriate (he used the body of a DJI f450), along with the power requirements needed to lift the new hardware that will be involved. A Raspberry Pi would be the logical choice for controlling this type of craft, though an Arduino board could also be appropriate in some instances. If a Pi is chosen, you’ll need to interface it with the flight controller using code like what is found here. This allows the Pi to emulate a RC input, while the stock flight controller takes car of lower level flight operations.
Once the interface is set up, you can of course connect the the Pi with a computer or phone app over Bluetooth or WiFi, but this also opens things up to any sort of sensor input or autonomous control options that you can imagine. Ultrasonics, for instance, would be appropriate for altitude hold or obstacle avoidance, or more advanced LIDAR systems could help the Pi map its environment. Computer vision via a webcam and OpenCV would be possible as well, opening up the door to even more enhanced functionality. With the exception of a LIDAR system, all of this would be doable for under $200.
While much of this piece will be review for those experienced with drones, it’s a good article for newcomers to the sport. It also features enough specific information that it would be useful to anyone looking to take their drone game to the next level!