# SHT20 Digital Thermostat

**URL:** <https://discourse.nodered.org/t/sht20-digital-thermostat/30399>\
**Category:** General\
**Created:** [20 July 2020 12:07 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399 "2020-07-20T12:07:55Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![Ki-va](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ki-va/32/22283_2.png) [@Ki-va](https://discourse.nodered.org/u/Ki-va)\
**Post date:** [20 July 2020 12:07 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/1 "2020-07-20T12:07:56Z")

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hi,  
I bought an **SHT20 Digital Thermostat Temperature Humidity Controller Sensor**  
and I'm having prombems connecting it to NR.

The sensor have 4 wires:

1. 3.3V
2. SDA
3. SCL
4. GND

I've connected the wires accordingly to the RPi 3+ and used the "DHT22" node.  
I've configured the nod to "Physical Pins rev.1"  
and the "Pin Number" once to pin 3(SDA) and once to pin 5(SCL) but with no luck. NR dose not recognize the sensor.  
Please help me configuring the sensor.

below is a link to the sensor for more information

> **[US $2.14 12% OFF|SHT20 Digital Thermostat Temperature Humidity Controller...](https://www.aliexpress.com/item/32960542094.html?spm=a2g0s.9042311.0.0.27424c4dz3EQYq)**
>
> Smarter Shopping, Better Living! Aliexpress.com

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**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [20 July 2020 12:11 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/2 "2020-07-20T12:11:47Z")

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The SHT30 is not a DHT22 and has completely different electronics so no surprises that it doesn't work with that node. I don't believe there is currently a direct node for that sensor since most people don't connect direct to the Pi but rather via an ESP8266/ESP32 or Arduino or similar.

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**Author:** ![Ki-va](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ki-va/32/22283_2.png) [@Ki-va](https://discourse.nodered.org/u/Ki-va)\
**Post date:** [20 July 2020 12:16 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/3 "2020-07-20T12:16:52Z")

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how can I connect the sensor via an ESP8266?

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**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [20 July 2020 12:31 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/4 "2020-07-20T12:31:43Z")

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If you are not familiar with programming one, try using something like the EasyESP firmware which I think may support it - you'll need to check. Assuming it does, you can flash that firmware onto an ESP and have it up and running in no time - just connect it to your Wi-Fi and send the data to your MQTT broker. Then you can listen to the MQTT output in Node-RED and display it and/or take action as needed.

Connecting the sensor to the ESP is a matter of knowing which GPIO ports are used for I2C and connecting accordingly as you've done with the Pi. I have a couple of these on breadboard setups with ESP8266's I've generally used the Bosch BMP/BME-280's in the past but the SHT30's seem pretty good too. All of the DHT series are rubbish (they are widely used since they were the first cheap Temp/Humidity sensors).

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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:** [20 July 2020 13:19 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/5 "2020-07-20T13:19:27Z")

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If it helps, an ESP-8266 flashed with ESP-Easy has support for DHT12 (I2C)

[https://www.letscontrolit.com/wiki/index.php?title=DHT12](https://www.letscontrolit.com/wiki/index.php?title=DHT12)

As @TotallyInformation says, it might be better (more reliable) using something like a BME-280.

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<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [20 July 2020 16:25 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/6 "2020-07-20T16:25:10Z")

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Mix-up there Dave I think. The question is about the SHT20 which is a modern and perfectly fine sensor. It is just that it is fairly new on the market.

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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:** [20 July 2020 16:26 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/7 "2020-07-20T16:26:12Z")

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Oops - I stand corrected.

I'll have to purchase some of those and try them out with a Wemos.

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<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [20 July 2020 16:27 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/8 "2020-07-20T16:27:15Z")

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Or maybe not that "new" since it was requested in 2017. It is included in core now by the looks of things:

[https://www.letscontrolit.com/forum/viewtopic.php?t=2363](https://www.letscontrolit.com/forum/viewtopic.php?t=2363)

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<div class="post-metadata">

**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:** [20 July 2020 16:29 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/9 "2020-07-20T16:29:02Z")

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It's probably in the 'Dev' version of ESP-Easy (which I don't tend to use).

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [18 September 2020 16:29 UTC](https://discourse.nodered.org/t/sht20-digital-thermostat/30399/10 "2020-09-18T16:29:05Z")

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