I2C bus verification:

General Questions
1

In Verification topic 3, section 2.4 I2C Bus Devices:
When run: sudo i2cdetect -y 1
the result for 6f is uu.
Is this the expected result?

The Real Time Clock battery looks to be in place.
But, very difficult to see because in cramped space
between board and frame.

2

We have an odd situation with the RTC address. The RTC is ‘owned’ by the kernel so we cannot see it like we can the other addresses. So yes, I believe it does show uu as I recall. I can check but that sounds familiar. Given a rev 5.x board you should be able to see the PCF8574 and if you have an OLED display that too will show up. Hope this helps. I should make a note of that in the learn docs so other people don’t get confused. Thanks for mentioning it.

1 Like
3

Ok, validated it shows ‘UU’ in addr 6F. I knew it was something with two letters.

For the RTC you can find out if the kernel recognized it on I2C by ls /dev and if you see /dev/rtc and /dev/rtc0 it means the kernel has seen the RTC and the device is active. This is a round about way but does verify the RTC is being seen.

1 Like
4

Today I have added a brief note explaining the UU showing up for the RTC.

At end of this page: https://learn.ubiquityrobotics.com/diagnostics

Thanks for pointing that out so we could make it a bit more clear in the docs.

1 Like
5

Thanks for confirming my observation.

6

Thanks for the added explanation. I suggest you also expand the text in Topic 3, section 2.4 to indicate that the 20 and 3c show the address and that the 6f location should show uu. This is were my question originated. Thanks for the great support.

7

Ah yes. Both locations now have a little table and better explanation.
Thanks

1 Like