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STM32F429 interferes with GPS signal reception.

YLene.1
Associate

Colleagues, I made a PCB project that contains Ethernet, GPS and STM32F429. but there was a problem. that GPS actively loses satellites when Ethernet is connected. I use RTOS and LWIP. I don’t know how to explain this ... capacitors - filters, did not bring results. but the effect is very obvious. as soon as the ethernet cable is connected, the GPS immediately starts losing satellites and at the end there are none left.

In internet searches I read that the F100 had a very noisy Flash and the F4 was sort of resolved. my GPS module is 4cm away from F429

Any help.

Thank you

1 REPLY 1

RF is complicated, and it starts with good design, multi-layer boards, and effective power distribution, with an understanding of how current flows, and the kind of CMOS switching noise you're dumping into the traces. GPS powered independently?

Is the antenna on the board design? They are going to be sensitive to clocks or GPIO's banging up and down. The IF for the receiver's baseband is apt to be 2-4 MHz for an L1 receiver. Not particularly hard to jam, signals from satellites travelling 25000 KM are pretty weak.

Any signals running under the GPS/GNSS modules?

What make/model?

The current generation of uBlox parts have a spectrum analyzer to review signals in the bands.

What type of Ethernet? 10, 100, 1000 Mbps?

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