# Send Limit Alerts while humidity\<30%

**URL:** <https://discourse.nodered.org/t/send-limit-alerts-while-humidity-30/14160>\
**Category:** Dashboard\
**Created:** [9 August 2019 01:51 UTC](https://discourse.nodered.org/t/send-limit-alerts-while-humidity-30/14160 "2019-08-09T01:51:40Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![dynamicdave](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dynamicdave/32/96_2.png) [@dynamicdave](https://discourse.nodered.org/u/dynamicdave)\
**Post date:** [9 August 2019 08:39 UTC](https://discourse.nodered.org/t/send-limit-alerts-while-humidity-30/14160/6 "2019-08-09T08:39:05Z")

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Here's a link to a soil moisture project that some of my IoT students tackled last September.  
It might give you some ideas to get you started.

> [@Soil Moisture Sensor/Monitor](https://discourse.nodered.org/t/soil-moisture-sensor-monitor/2745):
>
> [Soil Moisture Sensor/Monitor instruction sheet](http://resources-area.co.uk/node-red-flows/moisture_sensor.pdf)[Node-RED flow](http://resources-area.co.uk/node-red-flows/soil_moisture_monitor.txt)[Node-RED flow version 2](http://resources-area.co.uk/node-red-flows/soil_moisture_monitor_v2.txt) I've just finished writing-up an instruction sheet for my IoT students on sensing soil moisture in a plant pot. I've purchased 6-off of the inexpensive resistive moisture sensors. I've been told they are liable to corrosion so the program I have running in the Wemos D1 Mini uses "rules" and an NPN transistor to switch the 3V3 supply to the sensor on for 8 seconds every 15 minutes (which will hopefully reduce…

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