I’ve seen some brutal cuts from accidental arming of quadcopters, and had a couple of close calls myself, so was inspired to setup a safe arming switch. See below for how to do it
First we need to setup some logical switches, these look complicated, but aren’t that bad when they are broken down. This is what the switches do
- L7 only turns on when the Throttle is down completely, and the designated “start” switch is pressed (is use the momentary toggle SH switch), this doesn’t do anything by itself, but will be important later
- L8 are the arming conditions, basically your arming switch needs to be on (SE in my case), kill (holy sh!t!) switch needs to be off (SF in my case), and the throttle needs be down at the same time as the momentary switch is pressed (that we setup in the previous step (L7))
- L9 are the disarming conditions, basically if your arming switch is turned off or the kill switch turned on it’ll disarm.
- L10 puts it all together, it sets up a “sticky” switch, which is setup to turn on when L8 (arming conditions) turns on, and turns off when L9 (disarming conditions) turn on. The delay of 0.2 seconds is to make sure the start switch needs to be held for a certain amount of time before is arms (you can make it so you need to hold the switch for 2 seconds for example before arming).
This part can be done either through special functions, or the channel Mix screen which is how I prefer it done as I can see everything that can change channel outputs on the one screen, no nasty surprises hiding in special functions somewhere you might forget about.
Set up the following on your arm channel, and you should be good to go! Make sure you test it without props before taking it out to the field.
How does it work?
Turn on your arm switch, and hold the start switch for a moment and it’ll arm. Switching off the arm switch or engaging the kill switch will disarm, that’s about it 🙂