# Node-red-contribi2c (SHT31)

**URL:** <https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056>\
**Category:** General\
**Created:** [5 December 2020 15:58 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056 "2020-12-05T15:58:26Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![JEAN-MICHEL](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@JEAN-MICHEL](https://discourse.nodered.org/u/JEAN-MICHEL)\
**Post date:** [5 December 2020 15:58 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/1 "2020-12-05T15:58:27Z")

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Hi! I have a problem with i2C-scan with node-red.  
My Flow just uses i2c Scan and node debug.  
A SHT31 (temperature and humidity) is connected on Raspberry pi 4. It is detected with the console and the command i2cdetect -y 1. Adress 0x44.

But in node-red, i have a message: "Error: Invalid I2C bus number false"  
I have tested with another card i2c but it is the same problem.  
I2c is activate too.

I have tested with a program wrote in Python. (import smbus) that work very good.  
In node-red (node exec ), it is the same, very good.

I don't know what is the problem. Thank you for your help please!  
Jean-Michel

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**Author:** ![jkarsten](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@jkarsten](https://discourse.nodered.org/u/jkarsten)\
**Post date:** [5 December 2020 16:45 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/2 "2020-12-05T16:45:17Z")

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Hello,

i have the same Problem. My Node-Red installation is on an RPi3 and all was fine. Today i made an update to the installed nodes an now i have the same error message. i2cdetect gives me all Adresses on the Bus.  
So i used a new SD-Card and made a fresh install. Only with this node. Same result. "Error: Invalid I2C bus number false"

So i think my old installation is still ok but i dont how i can find the problem.  
Jörg

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**Author:** ![daimoniac](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/daimoniac/32/33149_2.png) [@daimoniac](https://discourse.nodered.org/u/daimoniac)\
**Post date:** [5 December 2020 16:57 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/3 "2020-12-05T16:57:55Z")

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same problem here.

msg : error

"Error: Invalid I2C bus number false"

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [5 December 2020 17:04 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/4 "2020-12-05T17:04:35Z")

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You can install the previous version for the moment by going to your `.node-red` folder and running  
`npm install node-red-contrib-i2c@0.7.3`  
assuming that the previous version was 0.7.3. Then restart node-red.

I see an issue has been raised so it will likely get fixed fairly quickly, then you can upgrade again. [https://github.com/nielsnl68/node-red-contrib-i2c/issues/37](https://github.com/nielsnl68/node-red-contrib-i2c/issues/37)

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**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [5 December 2020 17:07 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/5 "2020-12-05T17:07:29Z")

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version 0.7.5 published

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**Author:** ![JEAN-MICHEL](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@JEAN-MICHEL](https://discourse.nodered.org/u/JEAN-MICHEL)\
**Post date:** [5 December 2020 17:09 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/6 "2020-12-05T17:09:56Z")

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Thanks a lot. I am going to test immediatly.

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**Author:** ![jkarsten](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@jkarsten](https://discourse.nodered.org/u/jkarsten)\
**Post date:** [5 December 2020 17:10 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/7 "2020-12-05T17:10:31Z")

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It works very nice. Thank you.

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**Author:** ![JEAN-MICHEL](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@JEAN-MICHEL](https://discourse.nodered.org/u/JEAN-MICHEL)\
**Post date:** [5 December 2020 17:14 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/8 "2020-12-05T17:14:04Z")

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Very Gooood!!! Thank you!!!

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**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [5 December 2020 17:16 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/9 "2020-12-05T17:16:29Z")

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Phew ! - thanks for the quick feedback.

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [5 December 2020 17:19 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/10 "2020-12-05T17:19:37Z")

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> [@dceejay](#):
>
> version 0.7.5 published

I said it would likely get fixed fairly quickly, but 3 minutes is beyond normal expectations of 'fairly quickly'. 🙂

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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:** [19 December 2020 17:19 UTC](https://discourse.nodered.org/t/node-red-contribi2c-sht31/37056/11 "2020-12-19T17:19:40Z")

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