# Device to trigger flows based on power level threshold?

**URL:** <https://discourse.nodered.org/t/device-to-trigger-flows-based-on-power-level-threshold/35964>\
**Category:** General\
**Created:** [15 November 2020 17:40 UTC](https://discourse.nodered.org/t/device-to-trigger-flows-based-on-power-level-threshold/35964 "2020-11-15T17:40:57Z")\
**Posts on this page:** 1\
**Showing post:** 15

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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:** [17 November 2020 16:18 UTC](https://discourse.nodered.org/t/device-to-trigger-flows-based-on-power-level-threshold/35964/15 "2020-11-17T16:18:50Z")

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Here's a link to a non-invasive AC current sensor that is very easy to use with Node-RED.

> **[PZEM-004T 0-100A AC Communication Box TTL Serial Module Voltage Current Power...](https://uk.banggood.com/PZEM-004T-0-100A-AC-Communication-Box-TTL-Serial-Module-Voltage-Current-Power-Frequency-Modbus-RTU-With-Case-p-1562595.html?rmmds=myorder&ID=6273469&cur_warehouse=CN)**
>
> Only US$8.23, buy best PZEM-004T 0-100A AC Communication Box TTL Serial Module Voltage Current Power Frequency Modbus-RTU With Case sale online store at wholesale price.

More details of how to use it with a Wemos and a Raspberry Pi are here...

> [@Need to write one function that will return 3 values](https://discourse.nodered.org/t/need-to-write-one-function-that-will-return-3-values/30931/9):
>
> Yes i am just trying to show real time value on gauge which i received on MQTT, i have used JSON node.. Issue has been resolved, Thank you very much all of you guys. It would be great if anyone help me on making dashboard more attractive. I have attached SS which i had made.

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_[View the full topic](https://discourse.nodered.org/t/device-to-trigger-flows-based-on-power-level-threshold/35964)._