Pico-LoRa-SX1262 Pico-W Interference

After my own extensive testing, I have come to the conclusion that you SHOULD NOT use a Pico-W module with this LoRa module WITHOUT separation. This little board is my LoRa to MQTT gateway (via WiFi) for the Roverling project.

Wired like this, communication is good for 500+ meters line of site. With Roverling inside a large metal shed, and the base station 80m away inside and at the back of a timber structure, we get around -105dBm RSSI and an SNR of around -3dB. Excellent results.

Now, if instead you just stuck the LoRa module on top of the Pico-W, as it is designed to operate, and leave everything else the same, you will get a 10 to 20 dB drop in SNR as you start to go below -70dBm RSSI. This is only happens with the WiFi variant, if I use a plain old RP2040 Zero, good results again.

This is a massive difference, the Pico-W must generate so much noise as to swamp low level signals entirely. I would suggest, separate modules as far as possible, and to be sure I’ve even stuck a shield in between.

Important to note that the noise doesn’t impact transmitted signal from base station and in either configuration the RSSI and SNR measure the same at the remote end.



Possibly the close proximity of the WiFi antenna to the LoRa antenna is causing the swamping.
If the WiFi chip on the Pico is inactive it should not interfere.
The frequency bands are far enough apart but the RF outputs would interfere with each other.

Maybe you have the chip turned off, and I am wrong here.
But good to note the Pico W is not the best choice when using the LoRa board.


1 Like

Possibly the close proximity of the WiFi antenna to the LoRa antenna is causing the swamping.

100% correct, separation is key. Even checked RF outputs using an SDR spectrum analyzer. As expected no crossover, as you stated channels are more than far enough apart.

The solution looks ugly, but once you print a case…


Awesome troubleshooting, Mark!

I’ll update the LoRa module product page with this info so others can benefit from your excellent work.