Using The Momentary Switch To Arm Your Model with OpenTX

[@KirbyMiller]

2 year old video but I used basically these exact steps you show here to convert a momentary switch to a toggle on my EdgeTX Radiomaster Zorro. I’m still pretty new to this and you made the process simple. Thanks for taking the time to make this video!! Oh and the -1 to disable on start…I had no idea! No more turn on my radio and “disarmed, acro mode, high rate, blah blah blah” You have improved my life. Lol.

[@MrD]

You're welcome. I'm glad the video helped :)

[@choekstr]

It's 3 years old for me at this point and just set it up on EdgeTX ELRS Radiomaster TX12 MKII radio and it was identical steps. Love that EdgeTX and OpenTX are so similar. This more importantly frees up a 3 position switch for me to use elsewhere and let's me use a momentary button that are otherwise completely useless. Now I can have my arm 3 position switch be my rateprofile switch and my momentary button to arm while holding down. Absolutely incredible, thanks for taking the time to document this and provide this for the community.

[@kevalinopicks5555]

Wow Darren - there is so much to learn with Open/Edge TX! Thanks for another great tutorial.

[@MrD]

Thanks Kev, I’m glad the video was helpful 👍🏻

[@thingys-rd7id]

Very clear instructions and shown at a speed where I can copy what you are doing excellent video again Thanks. I can't understand why more people are not watching?

[@MrD]

Thanks. I’m glad that’s how the videos come across.

[@M-H433]

Just set this up today Darren,what an easy way to arm,its made things a lot easier,thankyou very much for this video.....your Gold my Friend.....

[@MrD]

You’re welcome Mark. One thing about this hobby is everyone does things slightly differently. So having more options to find what suits you is always good. That’s why I’ll release anything within reason. A video that looks pointless to some people could be just what others are looking for.

[@rongeernaert1208]

I go to setup my switches and logical switches on my Taranis QX7S thanks for this very good video !

[@StefanNaewe]

Interesting and just to the point as always, Darren!

[@MrD]

Thanks Stefan 👍🏻

[@williamschram]

!1x was a helpful insight to disable on start.

[@MrD]

Glad it was helpful 👍🏻

[@SerialKoE]

Awesome! Works perfectly and was exactly what I needed for my TX12. Thanks a lot!

[@MrD]

You’re welcome Christoph

[@mikekelly6774]

Thanks, this was really helpful. I got it working in Ethos as well. I originally assigned the logical switch to the throttle cut parameters but found that the transmitter powered up with the throttle active since logical switches are all off at power up and you would need the flick to be active. I got it working by using curves as you described in another video. I'm sure it would also work like you are doing here with inputs. The one thing that I am torn on is that if you walk up to the transmitter and see the throttle at idle, you don't have any visual confirmation whether it is armed or not - and it could be either. Using your two-state switch method from another video, if I see the switch in the armed position I can assume it is armed and worse-case scenario it may not be. I also like to hear a "throttle disabled" track play when I power up the transmitter, which I can do with the two-state method but I can't do with the momentary switch. It's great this can be customized in so many ways to meet our personal preferences.

[@MrD]

Thanks Mike. You make some great points here. Personally, I don't use this method, I prefer to use the physical two way switch. This was really an example for a request. It was also for use with iNav, which has checks it's self to make sure the throttle is low ect. I don't quite understand why ETHOS would have the throttle active. Having all the logic off when you boot up should be fine, as off for the logical switch is the disarmed position. It sounds like, if you used the default ETHOS throttle cut on the throttle mix. If it was armed when it shouldn't have been, the activating switch should be inverted. The "not armed" sound when powering up should also work. On OpenTX you set !x1 for not on start-up. But, on ETHOS it has a proper label. So the logical switch should trigger the sound. Great work though. It sounds like you're getting everything set up as you'd like it :)

[@MrSmithFPV]

Thanks for that. Will try that out on my Tango 2 with FreedomTX. 👍

[@MrD]

You’re welcome.

[@neomayad]

I went through and triple checked that i copied you exactly. I even started it on a new model but the throttle cuts to 0. Not -100. any suggestions on what I should do. I'm using the FC configuration @5:51 Disarm is MAX at -100 and and i can see the chart swing back in forth like yours does in the video. but it's till disarming to 0.

[@randygrinter2800]

Well done!!! Exactly what I was looking for. Thank you!!!

[@MrD]

You’re welcome Randy.

[@124MPH]

Brilliant mate, great video well explained. your a credit.

[@MrD]

Thank you. I’m glad they help 👍🏻

[@WernerBeroux]

I learned something today. 😉

[@InRemoteControl]

huge thanks my friend your video helped me a ton.

[@MrD]

Glad I could help Mayan. Happy flying 👍🏻

[@comsterfpv9668]

I was excited to see this and watched it quickly. It doesn't seem to use the prearm mode that I thought just got approved for iNav. Betaflight seems to have it. I was hoping to use this so that flipping an arming switch only works when a prearm momentary switch is also pressed. This is good for safety and allows better failsafe setup.

[@MrD]

I know that they are looking to add the Betaflight style prearm to iNav. If merged, it won't be released until version 2.7, which is still a few months away. It's personally something I'd never use as a fixed wing pilot, as I believe the safety checks in iNav its self are fine with a standard arming switch. Genuine question. How does it allow better failsafe setup? I could make a video on how to make a pre-arm in OpenTX, if people would find it useful. It would be very easy to do.

[@comsterfpv9668]

@@MrD The key problem is with older systems like EZUHF that can only remember a configuration of sticks and switches to replay on failsafe. You program them by pressing the failsafe button when the configuration is just how you want it, and the RX remembers. If you choose arm on, then the plane can suddenly arm on the ground if the transmitter is turned off accidentally. It doesn't matter if the radio has an elaborate procedure, the RX is just replaying the remembered channel setting. If you choose arming off, then you have to ensure your plane does the right thing in the air when disarmed. This is the safe setting, but it means your plane or quad drops out of the air where it failsafed unless the FC can do something smarter and handle reestablishing link smoothly too. You can help the FC do something smart by configuring a special condition like the throttle channel below what the radio will ordinarily emit by using trim tabs when you set up failsafe. It's a pain to get right, and you have to teach the FC this special condition. More modern RXs have an extra failsafe option to send no pulses on failsafe, which is a more surefire way to tell the FC it failsafed and put everything into its hands. INav and Betaflight can be taught to recognize this easily. I set up my EZUHF to disarm and have zero throttle in angle mode with a little pitch down and turning now. But with prearm available, I would configure it to RTH in armed state. Prearm should prevent it from arming on the ground or after landing if you are careless.

[@MrD]

That makes sense. I’ve not had to worry about older receivers that don’t have no pulses, hold, or cut; so I’ve never had to think about that situation. Thanks for sharing, it gives that feature a lot of sense now in that situation. The pull request is still open, but hopefully it’s something that will be merged in time for 2.7.

[@M-H433]

I still use all the immersion uhf systems with inav and have 2 stage arming and have never had an issue,all comes down to common sense,like how many arming systems do you need.

[@almason2843]

This is Perfect for those that fly RC helicopters and are used to arming switch on the top right. The only issue I am having is the idle up stays armed. Could you advise what change in inputs I need to make so momentary switch will also disarm the idle up curve. Thank you and great work!

[@doublehelix.]

Very handy, thx.

[@MrD]

No problem 👍🏻

[@skypeeper5930]

Why not vice versa ... use Short flick for arm and the long one for disarm ? So we don't accidentally disarm and in a panic situation have to wait longer to rearm.

[@MrD]

Because it is safer to have the hold for arm and the short flick to disarm. It should always be easier to disarm than arm, because you never know when it would be needed in an emergency situation. Peoples fingers and other appendages are more important than foam. Planes can glide, so if you have any kind of altitude at all, waiting a second or two to re-arm is not an issue.

[@carllubbok4375]

Great vid. Can you change a momentary Button to a 2 position Toggle switch?

[@MrD]

Thanks Carl. Yes, a momentary button would be the same as a momentary switch.

[@grlskce]

Can You explain how to program it, so it will arm after holding switch for 1,5sec and disarm after holding switch for 1,5sec. It would be much safer because now I can easily disarm my quad by accident

[@MrD]

I deliberately had the disarm instant for safety. I regard safety for humans over the plane or quad in this case. The whole point of a disarm switch should be to stop the motors as soon as possible. That 1.5 second disarm delay could result in more damage to somebody.

[@clintforeman2586]

Is there a potential safety issue if the throttle isn't at zero when the arming switch activates??

[@MrD]

Not if using a flight controller, as that will check the throttle position before arming. With just a receiver, yes. I would just use this as the switching mechanism and use my Ultimate Arm Switch for the actual arming. kzbin.info/www/bejne/bGPQqaRta8uCr80

[@edsorens]

Does the 'glitch' happen with other flight controllers (Betaflight, etc)?

[@MrD]

I don't know about BetaFlight. But ArduPilot could handle the error.

[@RubyS.1]

This is exactly what I been trying to figure out. Weird timing

[@MrD]

Sounds like perfect timing. Hope it helped :)