I2C BUS 1 Broken on Jetson Nano

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1 
Jetson Nano Developer Board
Jetpack 4.4

Problem with I2C BUS

The I2C 1 bus is incredibly slow.

i2cdetect -y -r 0 is snappy and returns address results in a few milliseconds.
However i2cdetect -y -r 1 takes about three seconds per address!

If I try to read or write to a connected board over i2c I inevitably get ERRNO 110 timeout error.

I have seen multiple other topic entries with similar problem concerning the i2c bus on nano dev boards. All ended up having to go through RMA process.

I am also getting various i2c probe errors on bootup which is concerning, I think the bus is completely corrupted.

Diagnostics

  1. I tried to reflash with a fresh JP4.4 sd card, but the problem persists.
  2. I checked voltage on sda/scl gpio pins which look correct

Questions

  1. Does anyone know why there are so many issues with I2C on nano boards?
  2. Is there a way to recover the i2c bus once it is corrupted? i2cdetect man does not seem to have any cmds regarding restarting the bus itself.
  3. Is there a way I can switch over to using I2C BUS 0 instead of 1 by adjusting the device tree?

Any tips/feedback or suggestions appreciated. cheers

3

Did you connect any device on this bus? I run the i2cdetect command on my side without problem.

4

Yes connected PCA9685 PMW Servo Module and cannot probe for address. I tried the same board on a Raspberry Pi and I am able to connect and communicate over I2C just fine.

It appears to specifically be a problem the I2C Bus 1, as mentioned before even the I2C 0 bus is working well on my nano.

8

This is the log I get at boot up.

Getting strange i2c probe errors on my imx219 board even though it is only connected over CSI.

IMG_20200918_150121
IMG_20200918_1501214032×2268 3.4 MB

9

Don’t understand what do you mean only connected over CSI?

10

Hey, you can pretty much disregard the IMX Error, just showing the strange i2c probe error I am getting at boot up time.

The core problem is that my I2C Bus 1 itself does not work.

11

Do you mean only connect the Pi v2 sensor on the Nano get the i2c error?

But imx219 is not connect to the bus 1 thought. “imx219 8-0010” it’s bus 8

12

@ShaneCCC thank you for your replies.

Yes, thats why i said strange error. I can check Bus 8 and I am retrieving addresses and everything looks ok.

However, I run into problems when I try to connect anything to Bus 1. I cannot even retrieve addresses on Bus 1.

I have tried connecting PCA9685 16 Channel 12-Bit PWM Servo Motor Drive which connects on Bus1 so it does not work. I connected to a Rasp Pi and it works correctly.

I also have tried to connect he Arducam PTZ board which uses Bus 1. Works on Pi but not on the Nano.

@ShaneCCC Do you have any recommendations on looking into why my Bus 1 is corrupted. Are there certain configuration files I should look at?

13

Have you try to connect to pin 27/28 bus 0?

14

Is this still an issue to support? Any result can be shared?

15

I ordered a new Jetson Nano board which fixed the issue-- can confirm it was a hardware issue with my I2C bus.

Thanks for the tip about using pin 27/28 for Bus 0. Will give it a try when I get a chance.