OpenTX safe arm switch for naked wings


When we fly naked planes or wings, there is no smart flight controller on board, which has some safety functions. All main safety routines depend on your habit. Many of us set an Arm switch function in the radio.

A typical solution for Arm switch is just overriding throttle channel by -100 value when the switch is off. Arming is actually removing this override. But there is still one dangerous situation. If the throttle is on some “running” position and turning the Arm switch on will spin the motor immediately to the throttle value.

So how we can allow arming only when the throttle stick is at the bottom? By using logical switches.

First L01 switch activates only when Throttle stick is almost at the bottom and Arm switch is on.
Second L02 switch activates on momentary action of L01 switch. It’s like a short button push to turn L02 on. L02 switches off when Arm switch is turned to the off position.

When you got L02 switch on, you can move Throttle stick freely. Only when you slam the Arm switch down, it turns off. Now let see what to do next.

This step is probably familiar to you. Instead of the Arm switch, we use negative !L02 switch to activate override of the throttle channel by value -100. This override function is active when L02 is not active or in the other words, the opposite of L02 is active. Note the exclamation mark.

Stay safe and enjoy flying!

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