A drone controller, often called the transmitter, is used by a drone pilot to fly and control the drone. In most cases, the controller uses radio signals to communicate with the drone or quadcopter. RC Controller technology hasn’t really changed much over the years, and neither have the controllers themselves.
Most quadcopter controllers have:
- 2 sticks, for controlling the channels
- An LCD display
- On/Off switch
- Trim adjustments
- Rate adjustments
Controllers provide a number a number of channels that allow separate transmissions to the controller. For quadcopters, the most popular personal drone design right now, the controller will have 4 channels. Each channel refers to a directional control for the quadcopter:
A 4-channel controller will have 2 sticks. The direction of movement of each stick uses the various channels. Here’s a photo on the controller for the Hubsan X4:
Most controllers support 2 modes of drone control:
- Mode 1 – The left stick controls Pitch and Yaw and the right stick controls Throttle and Roll
- Mode 2 – The left stick controls Throttle and Yaw and the right stick controls Pitch and Roll
Mode 2 is hands down the most popular, and generally the default setting for quadcopter controllers. The instruction manual that comes with your quadcopter will tell you how to switch modes if needed.
Which mode is best? There isn’t one single answer, and this is a commonly debated topic in various forums on the internet. The right answer is use the mode that works best for you, but consider the following:
- Once you get used to one, switching is very difficult
- Most modern pilots use mode 2
- Mode 1 is generally an older mode, but used by competition pilots
- Mode 2 replicates real world helicopter and quadcopter controls
All quadcopter controllers, even controllers found on low cost quadcopters, come with trim adjustments.
A common problem with quadcopter drones, especially on lower cost and older models is that they tend to drift. You’ll notice drift when you fly your quadcopter and it seems to “pull” in one direction, when the controller is in the centered position. Drift is very similar to when you are driving a car that is out of alignment. The car will pull to one direction or the other.
There are two primary reasons for drift:
- The gyro sensors aren’t perfectly adjusted
When flying outdoors, wind is the most common cause of drift. While you can adjust trim to compensate, doing so is difficult as the quadcopters flight direction is always changing. Adjusting for one direction, just makes the drift worse in the other direction. The best way to handle wind is to understand the direction it’s coming from, and adjust your flying to compensate.
When flying indoors or even outdoors with no wind, if you quad is drifting, chances are the gyro sensors are a little off.
The first thing you should do is land your quadcopter, and force a gyro calibration. This will cause the quadcopter to reset it’s “level” settings. The way this is done varies from quadcopter to quadcopter, so consult your manual or do an internet search on how to calibrate your model. We recommend calibrating your unit before each flight and always after a recharge.
If after the calibration, your quad is still drifting a bit, then it’s time to adjust the trim settings. Trim adjustments vary from controller to controller, but generally there is a way to adjust trim up or down for each of the channels. So if your drone is drifting left (roll), than you’ll want to trim the roll to the right some until it stops drifting.
Rate is generally found on more advanced controllers and allows the pilot to adjust the maximum settings for the channels. For example, if you’re flying indoors and you want to control throttle to a maximum level to keep your quad from smacking the ceiling, adjusting the rate would allow this.
Expert flyers can also adjust the rate up to allow more control of the quadcopter and make it more responsive. On the flip side, beginner pilots can adjust the rates down to make the quadcopter less responsive and easier to fly.
A few notes on rate:
- Many quadcopters come with beginner and expert modes. These modes are essentially adjusting the rates for you.
- A gyro stabilized quadcopter will only allow you to adjust the rates but so far, and will keep you from adjusting it to the point that the quadcopter will flip over. Although, many quadcopters come with special “trick flight” features that will cause your quad to do flips.
Here’s an example of a more advanced drone controller, the Spectrum DX6, which provides all of the features above, plus a number of others including being programmable: