Reading serial works on first run ONLY

[christoph.kohstall]

Hi Nvidia Community,

SETUP: I am using the Jetson AGX Orin Developer Kit and I am reading data from a microcontroller (Arduino). The Arduino is connected via USB cable and I am using python with the pyserial library. The microcontroller shows up properly as /dev/ttyACM0.

PROBLEM: On the first run everything works properly. On the second or third run no data can be received.

DEBUGGING:

• Only after unplugging and plugging the device back in it works again for one single time.
• I see the same behavior when I use the Arduino IDE and the build in serial monitor tool.
• It works fine on any other machine than the Orin.
• It works fine on the USB-C port close to the power jack but all other USB ports show the behavior described above. Also when used with a hub on said USB-C I’m back to the behavior described above.
• I observe similar behavior with an FTDI adapter that connects via USB.

Thank you so much for your attention and let me know if I can provide any further information.

[DaneLLL]

Hi,
The 4 type-A ports in Orin developer kit are one set of embedded USB hub. Please try this and see if it works after hub off/on:
Power down USB ports - #4 by vsaw

[rbelshaw]

Hi, I am experiencing this same issue with both a ORIN dev kit and ORIN module running in the following carrier board:

Carrier Board supports NVIDIA® Jetson AGX Orin™ Module - AVerMedia | AVerMedia

I will try this ‘turning it on and off again’ ‘fix’ once I get a chance however this issue does not exist on the alternative Intel NUCs we use. Should I expect this issue to be fixed in a later firmware update?

[jyang2]

Hi, I am currently experiencing this issue as well. Powering off then on is a functional workaround, but I’m also wondering if this issue will be officially fixed at some point?