# External Sensors on ruuvi tag

**URL:** https://f.ruuvi.com/t/external-sensors-on-ruuvi-tag/1053
**Category:** 🇬🇧 Electronics & programming
**Created:** [25 June 2018 06:42 UTC](https://f.ruuvi.com/t/external-sensors-on-ruuvi-tag/1053 "2018-06-25T06:42:48Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Atle\_Sjoblom](https://f.ruuvi.com/user_avatar/f.ruuvi.com/atle_sjoblom/32/1526_2.png) [@Atle\_Sjoblom](https://f.ruuvi.com/u/Atle_Sjoblom)
#### Post date: [25 June 2018 06:42 UTC](https://f.ruuvi.com/t/external-sensors-on-ruuvi-tag/1053/1 "2018-06-25T06:42:48Z")

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Hi.  
What kind of different sensors has been testet on the GPIO module?  
I would like to have one reed switch attached.  
What will be the best way to connect it. (What adress and connection points)

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<div class="post-metadata">

### Author: ![otso](https://f.ruuvi.com/user_avatar/f.ruuvi.com/otso/32/1651_2.png) [@otso](https://f.ruuvi.com/u/otso)
#### Post date: [25 June 2018 07:46 UTC](https://f.ruuvi.com/t/external-sensors-on-ruuvi-tag/1053/2 "2018-06-25T07:46:05Z")

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Hello,

I would connect the reed switch between one GPIO and GND pads and then copy the button press detection code to detect when the reed switch is closed. This is assuming normally open reed switch.

If the reed switch is normally closed, you’ll have to consider power consumption through pull-up resistor.