I2c is not detectable on Rpi 400 or Rpi 4 but is with Rpi 3s

I is there some thing that I am missing? I am having a bugger of a time getting i2cdetect -y 1 to find anything on raspberry pi 4s or 400s



Make sure you have enabled the I2C option in the raspi-config menu.

It it isn't enabled there, you are not going to get anywhere I feel.

Sorry if you have done it, but it is better to state the bleeding obvious than not. :wink:

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I did do that several times. You are correct to master the obvious first. The pi 400 magically started up last night (i2c) I It took several reboots.


I'd suspect a loose connection somewhere could be causing your issue

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Like @cymplecy said or have you forgotten the pull - up resistor?

The Pi has built in pull-ups on the i2c pins

Yep, should have remembered that!

The Rpi 400 detected the i2c BUS as soon as I did full upgrade and then upgraded to --node16 Node-RED. Don't ask me why. I am just happy to be back online. I am going to hold off on Bullseye and "OS Legacy" as long as my current Buster revs are doing what I need on my hardware. Too many fish to fry at the moment.



Good to hear all is now good. :slight_smile:

I have several PiZero running Jessie and very old NR versions :slight_smile:
They do the job I need them to and I leave them alone :slight_smile:

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