I've installed a sonoff mini and connected the signal wires to 3 3 way wall switches.
If I try to switch ON/OFF the sonoff using the app, there is no problem, it works like a charm always, but when I do it using the wall switches it just works "sometimes".
For what reasson can it be caused?
Is there any maximum length for the wires?
Should I activate any flag in the app?
c'est pas une solution le cable blindé, leurs produits ne sont pas au point ...
J'ai remplacé le sonoff mini par un QUBINO ZMNHND1 et ca fonctionne très bien, une force de vouloir vendre des produits à bas prix, ont négligé la qualité et le Sav.
I too am having this problem in a set-up with two 3-way switches. Sometime flipping one of the physical switches flips the light state, sometimes it does not. Using the eWeLink app, it always works.
At first I thought I had made a mistake with the S1 and S2 connections. So I disconnected the wires from S1 and S2 and attaches the wires to a multimeter to do a set of continuity checks, and it's working correctly -- flipping either switch flips the continuity, so all four combinations (up/up, up/down, down/down, down/up) work correctly.
Clearly the Mini is at fault and given other reports of people who've ordered multiples and have had some work and some fail is disheartening. This is clearly a buggy product and is not ready for market. And I was so excited when mine arrived....
I'm not an electrical engineer, but I believe this problem is fundamental to the design, and I'll be returning my Sonoff Mini. They chose to send the board voltage through the S1/S2 circuit, which is only 3.3 volts. As such, it's apparently susceptible to interference. They very similar Shelly line of products instead uses the line voltage through the switching circuit -- 110 volts or 220 volts. And that seems the more robust solution when it comes to unshielded house wiring.
But this issue has been on this message board for 4 months, and no one from Sonoff has bothered to respond. They really need to be part of the discussion.