i2cdetect and smbus

General Discussion
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Hey There,

So, it seems my addresses on the BeagleY-AI are deceiving me. I used i2cdetect to find my listed i2c device that is attached. I am not even sure if I need i2c but they are simply saying it on the data page which can be found here: https://cdn-learn.adafruit.com/assets/assets/000/022/655/original/raspberry_pi_schem1.png?1422045515

That is the schematic of the Cape/Hat in question. I do not see where things are mapped on the headers anywhere I go…

So, while online, I looked at Adafruit and other vendors for a connection. Ultimately, I have failed on this Cape/Hat. If anyone has any words of wisdom, please throw them my way. It is almost like I have to quit thinking because of my lack of knowledge on this subject.

Seth

P.S. The GND and PWR to the Cape/Hat work, i.e. signified by the lit LED. I am just thinking maybe someone or a group of people forgot to mention where PWM and/or GPIO get mapped on the Pi. If I knew, I could then transport their data and make it work for the BeagleY-AI. Right?

update

I just found on the docs.beagleboard.org pages online the correct way to handle i2cdetect: i2cdetect -y -r 1

Otay…onto to the next step…

It works!

I made a small post on Hackster.io here:

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:+1: :+1: :+1: That’s great that it works!

Let me know if I can be of any help with DC motors! (Battery arborist chainsaws use brushless DC motors so I get used to handling both AC and DC motor theory. :see_no_evil_monkey: )

Two things we’ve found using MIPI CSI-2 image sensors via I2C and i2cdetect that I reckoned I’d mention in case they help anyone else:

  • Some image sensor chips change what subunits they expose on the I2C bus depending on their power state - when in a low power state only one subunit address is visible on the bus but when powered up several new subunits appear at different addresses on the bus - this might happen with other complex I2C peripherals as well.
  • We’ think we’ve seen situations where there’s an I2C address conflict when a subunit on the SoC and an external peripheral on the same I2C bus try to use the same address on the same bus - until that happened I’d only thought about I2C address conflicts on I2C devices outside the SoC - not also any I2C devices inside the SoC.

Will

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