I made a modification to one of my Sonoff's See the pictures above.
This allows me to have a momentary push button wired to the Sonoff to turn it off/on or pair a remote control to it. The push button can be some distance away from the Sonoff
The reason I did this is because I intend to install the sonoff in the roof space of my house connected to a light circuit. I will then run the low voltage wire to my push button light switch on the wall of the room.
I can then activate the lights by either the wall switch, the 433mHz remote, or my phone.
It would be good if this was a standard feature of the Sonoff. It only requires installation of a terminal block connector socket and some openings made in the casing.
Think I might still check them out at the electrical wholesalers. I just don't trust that they are really momentary. Besides it takes a couple of weeks to get stuff on ebay to where I live and the I can get them today from the wholesalers (probably at an inflated price)
I am trying to achieve this as well (and I am sorry for my terrible english). I have up and down wall switches not momentary switch, what I want to ask you is if you could share more detail about your project cause I do not understand where i should put this momentary switches and how i can connect them to my new sonoff terminal block connector (are they wired till sonoff?!), should only the momentary switch be connected? And the legacy switch totaly disconnected from my home electric network?
Could you as well share your sonoff configuration to achieve this?
Hope you can support me been struggling with this for a few days now :(
The modification needed adds an external push button that works exactly the same as the button on the Sonoff. That is, when you press the button on the Sonoff it turns the power On / Off. The modification allows you to have a second button away from the Sonoff that does the same.
So a 2 wire connection block was glued in place and connected (soldered) to the existing push-button with 2 short lengths of wire. A hole had to be cut in the enclosure to get access to the new terminal block.
Installing the modified Sonoff needs a length of two wire cable to connect the added terminal connection to the switch. The switch must be a Normally-Open momentary type since the Sonoff uses closed circuit as a signal to turn off/on.
I mounted my Sonoff in the ceiling and connected it up as normal then ran the additional two wire cable to my lights switch. I replaced the up /down light switch with a button
There are no changes to the configuration (firmware or software) needed and all the normal (wireless) controls still work.
There is a big problem in your diagram.
If the light is turned off with wall switch, how can I turn it on with sonoff ? Because sonoff take tension from the wall switch in your diagram !! And so we have the same problem !!
Your diagram is ok for 3 of 4 total scenario. But here we talk about make all scenarios workinig !
If accidentally someone turn off the light with wall switch..... we can do nothing !
With the solution posted by @Ian Gough we solve every scenario !!
But if there is some other solution without open and solder the sonoff..... it would be better!
Você pode fazer como um interruptor comum ao usar o modo de instalação do comutador paralelo.
The switch is a contact closure to ground so distance shouldn't be a problem as long as the cable you use isn't ultra fine so that it causes very high resistance.
For me I used speaker wire (twin core) and my switch was about 6m away but it could easily have been 50m away without any problems.
Thank you so much for replying back to me, why wouldn't you connect it directly to the switch? Why does it need to be a momentary type? Wouldn't it work if you would have time to reprogram ESP8266, or am i seeing this all wrong? I think your solution might have saved my life (thank you so much for that)
You are right. Your is a good solution without any work to do.
but I think many others have thought of your own solution.
But here we were looking for a solution to solve any kind of scenario.
And welding the two files on the sonoff button we created an external button and then we can use each button of our house!
Maybe the best thig is to ask to Itead to solve this problem via hardware/software. And this is possible because Sonoff have a pin (gpio14) free for this use !!
The data we can input to the scratch are simple, like the integrated button :
wall button on = tension = (HIGH)
wall button off = no tension = (LOW)
Sorry I don't understand "why wouldn't you connect it directly to the switch?"
The momentary switch is needed because it is duplicating the function of the existing momentary button that is already on the board
I haven't tried reprogramming the ESP8266 but I would imagine that if you did you could configure it to use any switch you wanted