On a technical note, not much I can find about the signal quality. Phase noise, images, DC Offset, etc. Have to get my hands on one, ESP32-S31 seems promising.
The modems could be quite interesting as they are connected via PCIe which can eat a lot of bandwidth.
But they are very difficult (to almost impossible) to find if there isn't anything left in the firmware blob or device driver.
Why would they? It's perfectly legal to operate radio transmitters on any frequency you like, if you hold a suitable licence.
But right now, I've got an ESP32 WROOM module on a dev board sitting in my windowsill reporting some sensor values over wifi.
The WROOM itself is registered with the FCC[1]. If I stick to using the documented operation, then I have permission to use it in those documented ways. As a practical concept, I don't need a unique license to use it in the way that I am; I'm granted the ability to use it by Part 15 of the FCC rules.
And that's pretty great: The hardware was inexpensive to buy and very easy to find. I was able to spin this sensor up very quickly and get moving on the software side that deals with those readings. It has been a very rewarding little project with a fantastic cost:benefit ratio.
The fear being expressed here (which I don't necessarily subscribe to) is that things like this WROOM module will become less-available when/if methods to use it in undocumented ways are published and start becoming used.
(Up next, will you tell all of us that world isn't flat?)
We treat RF like your lot treat Mexican fireworks.
With the new ESP32-S31 we most likely can extract the I/Q data over its new 1 GBit/s interface. Guessing something around 20-40MSPS should work.
These hack will most likely will be a revolution for 13cm ham radio. With the new 5GHz ESP32 modules most likely also for 5cm. As all Espressif components are WiFi-qualified we can expect a very very stable and robust radio.
I ordered a few and waiting for Ali to deliver them to my lab.
> However, the current prototype uses the FPGA to clock the ESP32, which results in poor phase noise.
Looks like this was solved five days ago:
https://github.com/h0m3us3r/eSpDR/commit/41a0ffe279119df942e...
SDR in this context is software defined radio.
So kind of like those TV USB sticks that you can adapt into proper SDRs?
I remember the Ettus devices to be much much much more powerful.
RTL-SDR is the cheapest imaginable commodity implementation of SDR technology, while USRP was... well, pricy enough to bring in some solid revenue and get his company bought. More power to him, it was (and is) an incredibly useful platform.