# Non-blocking interrupt driven DHT22 library

**URL:** <https://community.particle.io/t/non-blocking-interrupt-driven-dht22-library/3673>\
**Category:** uncategorized\
**Created:** [March 29, 2014, 3:27am UTC](https://community.particle.io/t/non-blocking-interrupt-driven-dht22-library/3673 "2014-03-29T03:27:04Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![peekay123](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/peekay123/32/810_2.png) [@peekay123](https://community.particle.io/u/peekay123)\
**Post date:** [April 17, 2014, 2:42pm UTC](https://community.particle.io/t/non-blocking-interrupt-driven-dht22-library/3673/6 "2014-04-17T14:42:42Z")

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kareem613, my experience with DHT22s has shown me that not all are created equal! I use a 4.7K pull-up but it is not always necessary. Nonetheless, I suggest you use one because the non-blocking code is sensitive to the DHT22 data output rise time and the resistor helps. Another thing is the voltage used for the DHT22. I do not suggest powering off the 3.3\*v line since it is lower that 3.3V and I have found a lot of DHT22s that will not work at anything even slightly lower than 3.3V.

Try the pull-up and let me know how it goes.

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