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Mutually excluding outputs in Sonoff Dual for eWeLink

It would be great to have a mode for sonoff Dual (or 4 way) to set mutually excluding outputs, as in "when you turn on one, it previously turns off the other if it is on" so it can be used to control tubular motors (blinds, garage doors, etc)

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Just connect one output to a SPDT contactor and you can achieve this easily already


Hello Fionn. Do you mean a phísical (mechanical) SPDT contactor? That's not the point with these devices right? :)

Anyway, that would give a full up or full down situation. I want to be able to stop it at any desired height, as with any mechanical control for these tubular motors. (I'm using Bticino NT4027 from Legrand, for example, That would be easy with my "mutually excluding outputs" idea

I do mean a mechanical contactor but I don't think you understand what I'm proposing.
You connect the coil of a SPDT relay or contactor to a SonOff output.
Then when the SonOff is on, one output will be on and the other off, when you turn the SonOff off they will switch states. That should achieve what you want?


Hello. I also need this function. I have one tubular motor with 4 cables. First 220v for UP direction, second 220v for DOWN direction, third is neutral and forth is ground. If i use the new Sonoff 4ch PRO in interlock mode can i control my tubular motor? This device has 4 relays and with interlock mode, only one relay could be on, every time you turn on one relay, all other go to off automatically. So i can use the first relay for UP direction, the second relay for Down direction and the third relay without a connection only to STOP the other relays. Is this right, or i'm missing something here?

Again, just connect the outputs of the Sonoff that you want to use for "Up" and "Down" to a contactor each.
Use a contactor which has both normally open and normally closed contacts.

If you use a scheme like the one below, then the UP wire can't get power unless the DOWN wire is not powered and vice versa.
While SonOff may make products with a software interlock, the installation should still have fuses and other safety backups to ensure both outputs can't be on at once.


Some questions for your solution:

-You use 2 sonoff for this?

-Can you just stop the moter while in a move, and then start it at the same direction?

No, only one Sonoff required - SonOff Dual

Yes, no reason you couldn't restart in the same direction.

If you turn output UP on, output DOWN has no power until you turn output UP off and vice versa.
If somehow both outputs got turned on, the motor wouldn't move in either direction until you turned one output off.


This is very interesting because i already have simple sonoff's (not dual), i can use 2 sonoffs to make this happen. But can you provide some extra information about the 2 contactor's that you use in your diagram, perhaps a link to buy?

Check out the item below as an example, select 230V coil and 1NO + 1NC, it's £12. You would need 2.

Hi I have the same need. I have installed 6 Sonoff dual for driven my tubolar motors. Would be great to have a interlock function in the new app release. Because buying 2 coil for 6 motor  and install it is not easy....and the reason why I have buy the Sonoff is for the low cost...but if I have to add 2 Coil not a Low cost installation anymore. thks

Finally I flashed all my sonoffs with Espurna firmware, wich does it incredibly well

But obviously you can't use ewelink app anymore. You have to set up some Openhab, Domoticz or other software "to rule them all"

I'm also thinking to buy sonoff dual for my blinds. Is this functionality now supported in app?

I solve the issue using the Google Home app.  eWelink app is compatible with google assistant and in google assistant you can create a Routine(More then one action) and Now using Go UP and Go Down all blinds are working perfectly and when you said for ex to your Smartphone Go Up the first action is to disable both relay on all Sonoff dual , then enable one relay(in all Sonoff dual) to move the blinds UP and after 20 sec is again disabled all relays on all Sonoff dual. For going Down same thing. That's it

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