# Sonoff Mini R2 - S1 and S2

**URL:** <https://forum.ewelink.cc/t/sonoff-mini-r2-s1-and-s2/115373>\
**Category:** Free discussion\
**Created:** [January 4, 2025, 4:07pm UTC](https://forum.ewelink.cc/t/sonoff-mini-r2-s1-and-s2/115373 "2025-01-04T16:07:29Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![massimo](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@massimo](https://forum.ewelink.cc/u/massimo)\
**Post date:** [January 4, 2025, 4:07pm UTC](https://forum.ewelink.cc/t/sonoff-mini-r2-s1-and-s2/115373/1 "2025-01-04T16:07:29Z")

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Team,  
I need to have a check on an open/close door. I’ve tried the “wifi alarm” magnetic items but they do not work correctly as they get quite immediately the “open” but I never get the “close” signal.  
I was thinking to use a magnetic switch on the S1 - S2 on a Mini but I must be sure there is low voltage there or is deadly risky.  
I was not able to find any specs or documentation on this.

I think it’s important to specify the voltage on S1 and S2.  
I understood from several posts that there is a V3.3 difference S1-S2 but is it 0V-3.3V or is 220V-223V ??? it changes quite a lot 🙂

So please can you provide the official info and update the documentation?

Please note that deriving the info from the wiring diagrams is not good enough 😃

thanks  
M

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**Author:** ![ociepa.ekotox](https://avatars.discourse-cdn.com/v4/letter/o/c68b51/32.png) [@ociepa.ekotox](https://forum.ewelink.cc/u/ociepa.ekotox)\
**Post date:** [January 5, 2025, 1:58am UTC](https://forum.ewelink.cc/t/sonoff-mini-r2-s1-and-s2/115373/2 "2025-01-05T01:58:19Z")

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zbmini and minir2 have 3.3v on connector S1 and S2.

 ![Screenshot_20250105_025501_com.android.chrome_edit_92894615930615](https://europe1.discourse-cdn.com/flex005/uploads/ewelinkforum/original/2X/8/8203aaaedd84c3e127792dc017e80dcc86a98c96.jpeg)

MINIR4, MINIR4M, ZBMINIR2 devices have on connector S1 - 230V