balena container sometimes can't detect data from ublox gps chip

Product support
1

I’m working on a project that consists of a ublox ZED-F9P GPS chip connected via USB to a Jetson Xavier NX + dev kit. The SD card onboard the jetson runs a balena container.

Mostly the connection between the two workd properly, but about 30% of bootups result in the jetson detecting the GPS device on the ttyACM* port but being unable to read any data it receives. The issue is resolved by unplugging the GPS chip and plugging it back in. However, in the practical application of this project the jetson and GPS are not accessible, so it is not a feasible solution.

Because disconnecting and reconnecting the chip tends to solve the issue, we suspect it could have something to do with balena boot sequence.

Is this a known issue? Do you have any ideas for tests and/or solutions?

2

Hello,

I can’t find any internal examples of Jetson Xavier NX with ZED-F9P. However, in general to debug this type of problem, you can start by looking at the containers, to see if they’re all running properly (also helps to look at journalctl), then you can check dmesg output to see if there is indeed something during boot. Our Debugging Masterclass actually notes that “random” errors such as the one you’re describing are best examined through the kernel logs: Balena Device Debugging Masterclass - Balena Documentation