Zed-f9p loose accuracy with other devices in usb

Qwiic System
1

I have SparkFun GPS-RTK-SMA Breakout - ZED-F9P (Qwiic), I am connecting it to a ubuntu 18 machine. It runs as expected without problems until I connect another USB device, and the Horizontal and Vertical accuracies (hAcc, VAcc) become worst, and as soon as I uplug the other device from the USB, the hAcc and Vacc get back to previous ranges. The device I plug in is a realsense camera, but I also tried other USB devices and the same thing happens.

While reviewing the serial data flow, it appears that the speed slows down and less satellite are available.

I am trying to run a SLAM using the GPS and the realsense camera so this issue is very important to me.

The same thing happens over windows 10 (running u-center), but the hAcc and Vacc get worst only for a short period of time and it gets back to normal. While in ubuntu, it never get back to normal. For example I would have an accuracy of 0.1, that will become 5 after I plug the second device.

I tried in a raspberry pi, Jetson Tx2 and the same happens. Itried with hubs, no hubs, seperate ports etc… but no imporvements.

Any help is appreciated as I tried everything I know.

Thanks

2

It sounds like your other devices create some sort of RF interfere that affects satellite reception. Maybe try moving the antenna or using different / better quality usb cables on those devices.

3

You are correct. Used different cables and the problem appears to be related to that. Thanks a lot. I need to find good cables. Any suggestions on USB C cables?

4

Don’t really have a suggestion, just try a few and use what works. If you can find a cable that has the little bump in it, get that. Those are a ferrite bead an will help eliminate RF interference.

Here’s a pic of the “bump” I’m talking about.

https://showmecables-static.scdn3.secur … iew1_1.jpg