# Input device monitoring

**URL:** <https://forum.ewelink.cc/t/input-device-monitoring/9190>\
**Category:** Ideas & Suggestion\
**Created:** [November 27, 2022, 3:41am UTC](https://forum.ewelink.cc/t/input-device-monitoring/9190 "2022-11-27T03:41:20Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![myzhik86](https://avatars.discourse-cdn.com/v4/letter/m/7c8e57/32.png) [@myzhik86](https://forum.ewelink.cc/u/myzhik86)\
**Post date:** [November 27, 2022, 3:41am UTC](https://forum.ewelink.cc/t/input-device-monitoring/9190/1 "2022-11-27T03:41:20Z")

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Is there a device to monitor dry contacts of other relays, switches?  
want to monitor a contact closure.

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**Author:** ![f.montali](https://avatars.discourse-cdn.com/v4/letter/f/7cd45c/32.png) [@f.montali](https://forum.ewelink.cc/u/f.montali)\
**Post date:** [February 11, 2023, 4:07pm UTC](https://forum.ewelink.cc/t/input-device-monitoring/9190/2 "2023-02-11T16:07:10Z")

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Hi, I have the same request. Is there a device to control one or more (2-4) digital input?  
Thanks for reply

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**Author:** ![mario.bianchi](https://avatars.discourse-cdn.com/v4/letter/m/f17d59/32.png) [@mario.bianchi](https://forum.ewelink.cc/u/mario.bianchi)\
**Post date:** [March 3, 2023, 1:45am UTC](https://forum.ewelink.cc/t/input-device-monitoring/9190/3 "2023-03-03T01:45:29Z")

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You can use a Sonoff Mini that sense using low voltage (3.3V) or Dual R3 that has 2 inputs, but requiere live mains to sense those inputs.

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**Author:** ![sales3](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@sales3](https://forum.ewelink.cc/u/sales3)\
**Post date:** [June 7, 2023, 12:41pm UTC](https://forum.ewelink.cc/t/input-device-monitoring/9190/4 "2023-06-07T12:41:42Z")

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Would be nice to have the capability to have dry contact input device or update firmware and ewelink support of the extra input on the SONOFF SV Safe Voltage WiFi Wireless Switch.

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**Author:** ![beron1739](https://avatars.discourse-cdn.com/v4/letter/b/41988e/32.png) [@beron1739](https://forum.ewelink.cc/u/beron1739)\
**Post date:** [July 13, 2024, 1:08am UTC](https://forum.ewelink.cc/t/input-device-monitoring/9190/5 "2024-07-13T01:08:32Z")

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As input is it possible to use a modified Sonoff SNZB-04. This unit is normally used as window or door alarm and it is an input device. All you have to do is soldering the dry contact of your relay across the reed switch located inside the device. Normally this reed switch is operated by the magnet. Hense the coil voltage is your choice.