# How can I turn on a Raspberry PI GPIO pin based on presence of ~22vdc?

**URL:** <https://boards.straightdope.com/t/how-can-i-turn-on-a-raspberry-pi-gpio-pin-based-on-presence-of-22vdc/942751>\
**Category:** Factual Questions\
**Created:** [May 23, 2021, 6:21pm UTC](https://boards.straightdope.com/t/how-can-i-turn-on-a-raspberry-pi-gpio-pin-based-on-presence-of-22vdc/942751 "2021-05-23T18:21:40Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\
**Post date:** [May 23, 2021, 7:06pm UTC](https://boards.straightdope.com/t/how-can-i-turn-on-a-raspberry-pi-gpio-pin-based-on-presence-of-22vdc/942751/4 "2021-05-23T19:06:05Z")

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OK, hang on.

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