# I2C on Raspi3 + Buster + nodered 1.0 : help needed

**URL:** <https://discourse.nodered.org/t/i2c-on-raspi3-buster-nodered-1-0-help-needed/16361>\
**Category:** General\
**Created:** [5 October 2019 18:54 UTC](https://discourse.nodered.org/t/i2c-on-raspi3-buster-nodered-1-0-help-needed/16361 "2019-10-05T18:54:28Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jjs](https://avatars.discourse-cdn.com/v4/letter/j/94ad74/32.png) [@jjs](https://discourse.nodered.org/u/jjs)\
**Post date:** [5 October 2019 18:54 UTC](https://discourse.nodered.org/t/i2c-on-raspi3-buster-nodered-1-0-help-needed/16361/1 "2019-10-05T18:54:28Z")

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Dear all,  
I have a vergin setup Raspi3 + Buster + nodered 1.0  
I2C enabled, PCA9685 module connected (at default 0x40): i2cdetect reports 0x40.

A "node-red-contrib-i2c" "scan" in node red comes back with 64 and 128, which I do not understand. Is this correct?🤔

Now the real problem:  
 ![grafik](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/1/1e118d0d4993a1f0144d627fd8b6c9e45520c1ed.png)  
creates an error

 ![grafik](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/d/d0303e7ab9303978b23d0ae1a6c98db4d167b2af.png)

Can anybody help me getting the PCA9685 running under node red 1.0?🥴  
Btw. also an INA219 module did not work on the I2C

THX Josef

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<div class="post-metadata">

**Author:** ![jjs](https://avatars.discourse-cdn.com/v4/letter/j/94ad74/32.png) [@jjs](https://discourse.nodered.org/u/jjs)\
**Post date:** [5 October 2019 19:26 UTC](https://discourse.nodered.org/t/i2c-on-raspi3-buster-nodered-1-0-help-needed/16361/3 "2019-10-05T19:26:03Z")

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sorry, stupid me: scan result comes in decimals. So it is right.  
But the PCA problem remains.