# Problem with node-red-contrib-i2c

**URL:** <https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123>\
**Category:** General\
**Created:** [28 June 2020 19:24 UTC](https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123 "2020-06-28T19:24:04Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![fpsozio](https://avatars.discourse-cdn.com/v4/letter/f/c0e974/32.png) [@fpsozio](https://discourse.nodered.org/u/fpsozio)\
**Post date:** [28 June 2020 19:24 UTC](https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123/1 "2020-06-28T19:24:04Z")

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Hello! I'm trying to read a Lux Sensor in my RPi4 with the i2c node, but the "i2c in" node is showing the error "Error: Invalid I2C bus number 1", but if I use the node "i2c scan", I can see the adress of all my devices pluged.

 ![Node](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/8/0/800a58af3242595820d205d36611f4b8eeea4423.png) ![Config](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/b/f/bf3da7f266593f35243f40c4e046852efcee35a7.png)

Someone has already faced this problem, or know what I'm doing wrong?

Thanks!

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**Author:** ![edje11](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/edje11/32/572_2.png) [@edje11](https://discourse.nodered.org/u/edje11)\
**Post date:** [28 June 2020 19:39 UTC](https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123/2 "2020-06-28T19:39:15Z")

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I think that the BME280 node and BH sensor are trying to read at the same time and that are is a collision or something like that on the i2c bus.  
Place a delay node in front of the BH Sensor node to test and remove the i2c scan.

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**Author:** ![fpsozio](https://avatars.discourse-cdn.com/v4/letter/f/c0e974/32.png) [@fpsozio](https://discourse.nodered.org/u/fpsozio)\
**Post date:** [28 June 2020 19:43 UTC](https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123/3 "2020-06-28T19:43:01Z")

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Hi edje11! I tried now but the error persist

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/d/7d026fae451af4d1df4d812003579355e4431eae.png)

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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:** [28 June 2020 20:10 UTC](https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123/4 "2020-06-28T20:10:39Z")

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hi - apologies for the breakage - fix pushed - try v0.7.2

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**Author:** ![fpsozio](https://avatars.discourse-cdn.com/v4/letter/f/c0e974/32.png) [@fpsozio](https://discourse.nodered.org/u/fpsozio)\
**Post date:** [28 June 2020 21:28 UTC](https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123/5 "2020-06-28T21:28:29Z")

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Thanks a lot dceejay! I have updated, and the v0.7.2 is working good!

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**Author:** ![Nodi.Rubrum](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/nodi.rubrum/32/107482_2.png) [@Nodi.Rubrum](https://discourse.nodered.org/u/Nodi.Rubrum)\
**Post date:** [30 June 2020 06:30 UTC](https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123/6 "2020-06-30T06:30:37Z")

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Mind publishing the complete flow? I have about 10 separate i2c devices I am going to build flows for, and your flow would be a great example to learn from.

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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:** [14 July 2020 06:30 UTC](https://discourse.nodered.org/t/problem-with-node-red-contrib-i2c/29123/7 "2020-07-14T06:30:44Z")

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