When you’re learning acro mode and new freestyle tricks, or occasionally when racing, it’s all too easy to get disoriented and start heading for trouble. Wouldn’t it be great to have a “panic” button that would immediately set your quad upright, then let you get back to flying? Today we’re going to set up a momentary switch on the radio to do that.
A momentary switch is one that won’t hold its position; it will reset itself when you let go instead of staying in place. Most hobby-grade radios have one in an easy-to-reach location, which is perfect for this purpose. We’re going to make it so that as long as you are holding this switch, your quad will use auto-level mode. If you’re already flying in an auto-level mode like ANGLE, the switch won’t do anything—but if you’re flying in acro/rate mode, it provides immediate (but temporary) access to the auto-level feature. This can be very valuable when you’re still getting comfortable learning to fly in acro.
How to Use It
Learning to fly acro mode is a very big mental shift from flying ANGLE with auto-leveling. Start learning on a simulator, because you will crash—a lot. Eventually you will launch a real quadcopter into the air in acro. While the simulator time will help immensely, there will still be some differences that take getting used to. Your rates may not match those from the sim, or you might be comfortable but then try something more advanced. Either way, you may find that you have finished a move and are at an odd angle or upside-down. If you have enough altitude, try to get out on your own as this will help you learn faster. If you find yourself in a panic, throwing the switch may save you from an expensive crash.
While racing, the panic button can be useful after you collide with something. If you catch it quickly enough and allow the drone to stabilize itself, you may recover from the collision and stay in the air. This is one reason many pilots fly ANGLE mode indoors, where colliding with objects is much more common. However, using acro mode during a race typically allows pilots to fly faster. Having a panic switch allows you to access stabilization quickly and disengage it just as easily to continue your flight.
We’ll be setting this up on a FrSky Taranis X9D radio. The steps will be similar on other OpenTX radios.
First, find the channel that transmits your flight modes. In our case, it’s CH6 (AUX 2). Find out which position you need in order to get your quad into ANGLE, or auto-level mode, and note the channel value. If you don’t have a mode switch, you’ll need to set up a flight controller channel to do this. Take a look at our betaflight configuration guide to get started.
Open the Special Functions page. Set a function to activate when your momentary switch is on. On a Taranis X9D, that’s SH-up. For the feature type, chose OVERRIDE CH6 (or whichever channel switches your flight mode). The value you set will depend on the switch position you need to get into ANGLE mode. For this example, ANGLE is in the center, so the value is 0. Make sure you turn the function ON.
Believe it or not, that’s all there is. When you pull the switch, the override takes place and dumps you into ANGLE mode. When you let go, it restores whatever position the channel was at before. You can test that it is working in the Betaflight MODES tab. Watch the position of the channel change as you flip and let go of the switch.
The “Panic button” is good for more than a quick fix for being disoriented. It can also help with landing: flick it once to ensure you’re level before setting down. Or if you need a little more help, hold it while you concentrate on throttle control. As you get more experience, you’ll use the panic button less and less. Eventually you won’t use it at all. Once you’ve reached that point, give yourself a pat on the back and free up that momentary switch for another purpose. Maybe you’re ready to set it up as a trainer—the original intended use of the momentary switch—and help someone else learn to fly.