Using ESP32-S2 without WiFi

[atlaste]

Hi there,

I've been wondering for some time now how I can make an ESP32-S2 module without any WiFi functionality. I have some real life applications for this.

https://www.espressif.com/sites/default ... nes_en.pdf gives an overview of the hardware design guidelines. We've made some modules before that work fine, and I'm happy to cut some lines / remove some components. So, I was wondering... if I remove the antenna, the ESP is probably going to attempt to compensate, which I guess will give issues. There are some 3.3v lines near the antenna that seem to be powering that part of the IC, if I recall correctly pin 3/4.

Can I just cut them should that work fine? Or is there some other (small) way to terminate/disable this part of the IC?

Kind regards,
Stefan.

[ESP_Sprite]

Generally, you can cut the LNA (antenna) line if you don't want WiFi, but we'd also advise modifying the firmware to never initialize the WiFi stack. I'm not sure if cutting the power line is that good an idea as the power domains aren't independent and you'll get leakage current from the other parts of the chip into the analog WiFi circuitry, which may lead to undefined behaviour.

[atlaste]

First off, thank you for the very informative reply!

I assume you advice that we never initialize the wifi stack to ensure that the IC won't be damaged. From your comment I also assume that not initializing it means that the LNA_IN/RF pin won't be used at all (until `coax_init` is called I suppose).

Which made me wonder what the best way would be to terminate the LNA/RF pin?

[ESP_Sprite]

Yes, that's correct. And from what I heard from the hardware team, the best way to 'terminate' it would be to simply leave the connection open.