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wmchen 15 hours ago [-]
I'm really excited to see what will come of this discovery. I will mention OpenTrafficMap [1][2], which leveraged the ESP32-C5 to collect 802.11p V2X communication data (Cooperative Intelligent Transport Systems) from traffic lights, vehicles and other road traffic sensors. This project in particular got me excited about what could be accomplished with these microcontrollers.
Not the first time I read about OpenTrafficMap but I'm still not clear what it actually aims to achieve. It seems to me as if it would only start getting useful (rather than just interesting) with several thousands receptors throughout a whole country, but it seems unlikely to happen.
So many $1 wireless ICs have a powerful "SDR", but will never be documented due to certification/compiliance/export-control reasons. The projects listed here rightly limited the scope to RX-only but Espressif might be forced to "patch" this away if arbitrary TX too is possible (or starts making headlines). Hope it doesn't come to that, more cheap options for RF-to-bits is always welcome.
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.
BlackRabbit1 1 days ago [-]
I'm pretty sure that that WiFi-7 modems/routers have a similar modes up to 320MHz bandwidth.
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.
unrented7977 4 hours ago [-]
They can't patch anything, it's a hardware feature. They'd have to spin new silicon for every single product in their lineup and trash the likely millions of units they have in stock.
This is no different from a CB radio where you can lift the cover and tweak some adjustments for higher (read: illegal) TX power. This is a normal, expected development feature which requires extraordinary effort for users to find and abuse. Espressif is almost certainly in the clear
mallets 3 hours ago [-]
They could release new binary blobs to block this. Useless at this point but could amount to trying their best.
Closed binaries aren't much of a deterrent these days, we might see more such "discoveries" for a lot of devices.
ErroneousBosh 1 days ago [-]
> The projects listed here rightly limited the scope to RX-only but Espressif might be forced to "patch" this away if arbitrary TX too is possible
Why would they? It's perfectly legal to operate radio transmitters on any frequency you like, if you hold a suitable licence.
ssl-3 1 days ago [-]
It is legal for a person with an appropriate license, yes. But laws (in the US) about RF transmission differ from how many other laws are structured: We're only allowed to transmit what we have permission to transmit -- and by default, we're forbidden.
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.
>>"We're only allowed to transmit what we have permission to transmit -- and by default, we're forbidden."
It is not true that by default you are forbidden to transmit. In fact there are quite open rules in some ways for transmissions. Whenever these discussions about transmission come up there's always people who, without really undrstanding, freak out about transmitting anything and declare that all tranmissions are illegal. Not so.
USA hobbyists can legally transmit without a licence under FCC Part 15, but the limits are pretty low and depend on the frequency. AM, up to 100 mW into the final RF stage, with the antenna, feedline and ground limited to a total of 3 metres. FM maximum field strength of 250 µV/m measured 3 metres away. There are special cases, such as 49.82–49.90 MHz, where home-built transmitters can go to 100 mW on a 1 metre antenna. One-off home-built transmitters don't need FCC certification if for personal use not being sold.
We're granted permission to make the transmissions you speak of; it is otherwise deny-by-default. This is described right there at the top of your first link, in the first three paragraphs.
It's broadly possible to sort any rule (or superset or subset of rules) into one of two different buckets:
One bucket contains the rules about the things things we're not allowed to do. Like a firewall with a blacklist, whereby we can do whatever we want that explicitly isn't blacklisted. It is allow-by-default.
The other bucket contains the rules about things that we are permitted to do. This is like a firewall with a whitelist, where we can do whatever the whitelist explicitly allows us to do and nothing more. It is deny-by-default.
Drug laws in the USA are in the first bucket (blacklisting). Radio transmission rules in the USA are in the second bucket (whitelisting).
(There is no third bucket.)
Borealid 15 hours ago [-]
I believe the default state, in the absence of any law whatsoever, is that you can do whatever you want. Nothing is forbidden by default. You could assault another person, and it would be legal absent a law forbidding it.
Then there are laws that prohibit things like broadcasting radio signals without a license.
Then within those very same laws there are exceptions allowing certain transmissions WITHOUT a license, in specific circumstances.
The "default" is that things are legal unless they are made illegal, and I think it's pointless wordplay to try to argue the default state is somehow the law prohibiting unlicensed operation, and not the part of those same laws that allow unlicensed operation in particular bands with particular transmission power limits.
I understand the point you're trying to make that some parts of U.S. law say that all not-explicitly-mentioned radio transmissions are unlawful, but that's not meaningfully different from drug policies that say that all "harmful substances" are unlawful and so forth. They all just boil down to what the law defines as being within its own scope.
ssl-3 15 hours ago [-]
Yes.
And in the United States of America, at least: Radio transmissions are illegal by law, except where permission is granted by law.
(Try not to overthink it too much. A previous responder provided a citation that did not serve them well.
This situation can seem ugly or fantastic or jubilant or something else -- and it can be changed! -- but it still is just is how it is.)
fc417fc802 13 hours ago [-]
I think your analysis of the situation is correct. I just want to point out that what you are describing resembles a form of tyranny to me. Radio, flight, and food are all everyday domains that I appreciate absolutely require regulation for society to function smoothly however the FCC, FAA, and FDA have to be among the most anti-american institutions (or rather bodies of regulation) I can immediately think of.
ssl-3 5 hours ago [-]
Maybe I'm an asshole sometimes and legal restraint is what keeps me from mounting a bunch of microwave oven magnetrons on a tower and killing the 2.4GHz ISM band for miles in any direction, or re-tuning my FM transmitter to step all over the aviation band just for the lulz.
I can grow my own food. I can share it with my neighbors. In Ohio, at least, I can sell a ton of produce every day to random strangers at any price that we find to be mutually acceptable, and I can do this without any licensing, inspection, or sales tax burden.
But I don't grow much of my own food; I never wanted to grow up to be a farmer.
I mostly consume products of industrialized agriculture. The USDA, FDA, and FTC help to ensure that the national brands I buy from the grocery store contain what they say they do, and that they're safe to consume, and that I get something close to the amount of it that is printed on the label.
When I buy a 5-pound bag of wheat flour from the grocery store today it weighs in at right around 5 pounds and is made from wheat. Yeah, there's some stragglers from other plants in the process and a completely non-zero number of insect parts and stuff, but it's not like there's a special department that grows bugs just to throw them into the mix. The goal is to simply produce and deliver wheat flour.
There was a time when adulteration and substitution of food was common and deliberate. We used to bulk up flour using cheap minerals that we'd dig out of the ground that had zero nutrition, such as gypsum. This kind of thing serves as proof that companies are assholes when left to their own devices.
I guess we could go back to letting them do just fucking-whatever again, but do you really want to have to analyze all of the food that you buy in order to gain knowledge of what's actually in there? (How else would you be able to make an informed purchasing decision?)
Anyway, that sounds like a ton of work compared to paying a little extra to have other people do it for me, whereby I can just read the ingredients label and know with pretty good surety what's inside the bag.
I live in a society. I make money doing things that I'm good at doing, and I use this money to pay people to do stuff that they're good at doing -- and to make sure that they're doing it right.
fc417fc802 3 hours ago [-]
> Maybe I'm an asshole sometimes and legal restraint is what keeps me from mounting a bunch of microwave oven magnetrons on a tower ...
That would be illegal regardless? Please note my earlier up front acknowledgement that these areas of society do indeed appear to require some amount of regulation. I never presented an argument for a laissez-faire approach.
> I can grow my own food. I can share it with my neighbors. In Ohio, at least, I can sell a ton of produce every day to random strangers ...
If you look into it more deeply I believe you will find that your mileage varies in some surprising and offensive ways.
> The USDA, FDA, and FTC help to ensure that the national brands I buy from the grocery store contain what they say they do, and that they're safe to consume ...
Certainly they do. (I never disputed the need for this BTW. In fact I explicitly acknowledged it. Are you sure you're actually responding to what I wrote? Like at all?) Although since you brought it up I'll point out that they also fail in a number of ways. Consider for example the long standing failure of the FDA to competently audit the composition of "supplements". Or recall that time that the consumers bringing a lawsuit for false advertising over "real juice" lost. If you simply ignore all the gaps then sure it can be made to look like we do a great job in the US.
> I guess we could go back to letting them do just fucking-whatever again ...
Yeah nowhere did I suggest that. The opinion that regulation of the commercial food supply is necessary and the opinion that the FDA as it currently stands is a flaming pile of shit aren't mutually exclusive.
mmmlinux 5 hours ago [-]
That sounds like a list of things your permitted to do, by the fcc.
ErroneousBosh 1 days ago [-]
The FCC is relevant in exactly one country in the world.
TeMPOraL 1 days ago [-]
Other countries have equivalent organizations and they all tend to be in sync on this stuff.
Borealid 15 hours ago [-]
Unfortunately the use of the Wi-Fi 5Ghz spectrum is not at all in sync worldwide. See https://en.wikipedia.org/wiki/List_of_WLAN_channels#5_GHz_(8... and how meaningfully different the rules are for how you can set up your own home wireless network in different parts of the world...
fc417fc802 13 hours ago [-]
Worse is the OEMs all gradually removing the ability to operate modems intended for general purpose devices as APs in the 5 GHz range. The trend is to lock the firmware to only reply as a client in those bands. Meanwhile it isn't uncommon to encounter cheap dedicated APs that operate under the incorrect regulatory domain for the country they're sold in. So the cure doesn't work yet we lose the ability for P2P outside of 2.4 GHz.
(If they happen to be reading I'd like to offer a hearty fuck you to whoever at Intel and Qualcomm initially decided on these absurd policies.)
diydsp 11 hours ago [-]
Yep. Plus there are international, worldwide organizations bt those agencies; the ITU. Internatl Telecom Union.
Prologue. We get it, GP hates the u.s.-centric view. Found on this american website.
mmmlinux 5 hours ago [-]
Not true. In some countries you can be prosecuted for just receiving signals.
zoobab 12 hours ago [-]
I created a new country Zooland where there are not RF regulations:
For the same reason, those regulations (FCC radio lockdown etc) stifle innovation in the SDR world.
skinfaxi 10 hours ago [-]
Is not some regulation necessary? Spectrum is limited. You seem to have thought a lot about this so curious about your perspective.
smallmancontrov 9 hours ago [-]
Spectrum used to be a lot more limited when frequencies had to be exclusive and baked into hardware designs. Now we have agile radios that can tx/rx across wide bands and dodge other peoples' traffic, so the motivation for exclusivity is a lot weaker. If you walk around with a spectrum analyzer you will see traffic voting with its feet and overwhelmingly choosing the free-for-all ISM bands because dodging other peoples' packets is easy compared to obtaining spectrum licenses around the world.
So: the optimal regulatory approach changed, the laws didn't keep up, and now we have suboptimal regulation that isn't bad enough to spur a fix and vested interests (spectrum owners) who don't want it fixed so I expect it to continue for a very long time. So it goes. It's not great but if all the world's problems were as small as this one it would be a much nicer place.
mmmlinux 5 hours ago [-]
My spark gap transmitter doesn't care about your spectrum. Regulation is important.
1 days ago [-]
amelius 11 hours ago [-]
Think of this scenario. What if there is a botnet that these ESP32 modules become a part of, and they all start transmitting garbage, simultaneously ...
(This is why you will never truly own your smartphone, even though you paid for every chip inside it)
mallets 1 days ago [-]
Legal for end-user, sure. But Espressif might run into trouble with regulators like FCC.
ErroneousBosh 1 days ago [-]
Then sell them in the UK, where the FCC is entirely irrelevant.
We treat RF like your lot treat Mexican fireworks.
compiler-guy 1 days ago [-]
This would mean throwing away a giant market for what are generally pretty niche use cases. Very cool use cases, sure. But not worth giving all those sales up in favor of gray-market importers.
gamblor956 1 days ago [-]
Our border control confiscates Mexican fireworks.
Joker_vD 17 hours ago [-]
And illegally entering Mexican immigrants too, yes. In practice, neither seems particularly effective.
numpad0 19 hours ago [-]
Certified unlicensed radio equipment are required to be reasonably tamper resistant, so that reasonably everything that end users might do would be practically compliant even with a bit of malice. This is one of reasons why iPhone used to use pentalobe screws.
They are not required to be as secure as credit card chips, but they also can't be wide open.
You don't need much to spam random RF energy into the air. That project just flips a GPIO pin at the right frequency, and gets a signal into the air.
It won't be very powerful, and the harmonics will probably bleed all over the place if you just hang a wire off of it with no filters.....
Gibbon1 16 hours ago [-]
An SX1262 has a frequency range from 150MHz to 960 MHz.
Actual FCC licensed products are supposed to not be naughty. But nothing prevents components from being naughty.
Inside ISM bands there are rules but beyond that anything goes.
BlackRabbit1 1 days ago [-]
As far as I follow the research process it's currently quite difficult to get all data (like the 80MSPS@10-Bit showcase on Reddit) to a computer without a FPGA+USB3.
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.
rasz 1 days ago [-]
>FPGA+USB3 80MSPS@10-Bit
>compresses to about 1.2 bytes per pair, around 95–100 MB/s
No mention what FPGA platform/board used, FT600 USB chip is ~$10 alone.
Now you can replace all of it with one of those silly $5 FX2LP USB 2.0 dev boards. CY7C68013A-56 supports 16bit interface and will happily pump 30MB/s all day long for a fraction of the price. $10 total for 2.4GHz ~12MSPS@10-Bit SDR.
rmast 23 hours ago [-]
The GitHub README says the FPGA used: Alchitry Au (Artix-7 XC7A35T, 256 MiB DDR3)
rasz 36 minutes ago [-]
and a day later https://github.com/ESPARGOS/SoapyESPSDR already got native ESP32-S31s USB 2.0 working streaming 20 MSa/s @8bit, pretty amazing at $7 + shipping.
1e1a 17 hours ago [-]
This is absolutely fantastic! Testing with an esp32-s3, it looks like the tuning range is roughly 2.2GHz to 2.8Ghz, which covers far more than just WiFi. It should be possible to receive and demodulate S-band satellite downlinks using this < $2 chip with a dish.
Are we seeing an uptick in the number of posts/chatter around ESP32 of late?
I recently got interesed in hobby electronics again and happened to lookup what I can do with an ESP32 -- and since then there has been at least one HN front page post about ESP32 every day. Not sure if it is just a frequency illusion.
NitpickLawyer 7 hours ago [-]
The barrier to entry is much lower now. Not necessarily to entry but to do actual useful stuff. You can point your fav agent at it and tell it to do things besides "light up a led". That could also be a factor.
ACCount39 9 hours ago [-]
ESP32 was always a popular series for hobbyists and low volume embedded. Among the cheapest and most easily available ways to get Wi-Fi or BT into your microcontroller project.
cellular 21 hours ago [-]
Any way to finagle a LORA type system (ultra reliable using precise timing) using a few of these on each end?
mrheosuper 20 hours ago [-]
The ESP32S3 support PSRAM, can we redirect the sample to PSRAM, then hooking Logic Analyzer on PSRAM, thus getting the sample directly, not through any digital interface.
(There is cache before PSRAM, but should be trivial to sync).
ACCount39 9 hours ago [-]
Wouldn't that just be limited to the speed of SPI that PSRAM is hooked to? Might as well blast it out of SPI itself.
thenthenthen 8 hours ago [-]
This is very cool and hope to leverage this for education. At least some of the principles. The cheapest decent sdr dongles are already a huge part of the budget.
ErroneousBosh 1 days ago [-]
> undocumented feature that lets the firmware bypass the fixed WiFi and Bluetooth functionality and instead capture raw IQ baseband samples
So kind of like those TV USB sticks that you can adapt into proper SDRs?
wiml 1 days ago [-]
The ones that the website hosting this article is named after?
brcmthrowaway 1 days ago [-]
Yep, Matt Ettus converted that to hundreds of millions of dollars
I have a couple of Kanga Finningley SDRs bought through the G-QRP club, but they appear to have almost entirely vanished from the Internet.
th0ma5 7 hours ago [-]
[dead]
CamperBob2 1 days ago [-]
Not with RTL-SDR specifically but by introducing one of the first open-architecture SDRs, the USRP.
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.
[1]: https://opentrafficmap.org/
[2]: https://www.cnx-software.com/2026/05/24/opentrafficmap-esp32...
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.
This is no different from a CB radio where you can lift the cover and tweak some adjustments for higher (read: illegal) TX power. This is a normal, expected development feature which requires extraordinary effort for users to find and abuse. Espressif is almost certainly in the clear
Closed binaries aren't much of a deterrent these days, we might see more such "discoveries" for a lot of devices.
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.
[1]: https://fccid.io/2AC7Z-ESPWROOM32
It is not true that by default you are forbidden to transmit. In fact there are quite open rules in some ways for transmissions. Whenever these discussions about transmission come up there's always people who, without really undrstanding, freak out about transmitting anything and declare that all tranmissions are illegal. Not so.
USA hobbyists can legally transmit without a licence under FCC Part 15, but the limits are pretty low and depend on the frequency. AM, up to 100 mW into the final RF stage, with the antenna, feedline and ground limited to a total of 3 metres. FM maximum field strength of 250 µV/m measured 3 metres away. There are special cases, such as 49.82–49.90 MHz, where home-built transmitters can go to 100 mW on a 1 metre antenna. One-off home-built transmitters don't need FCC certification if for personal use not being sold.
It's pretty interesting to read if you are a radio head: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A...
https://www.ecfr.gov/current/title-47/section-15.209
"operation within these frequency bands is permitted under other sections of this part, e.g., §§ 15.231 and 15.241."
-->
0.009-0.490Mhz 0.490-1.705Mhz 1.705-30.0Mhz 30-88Mhz 88-216Mhz 216-960Mhz Above 960Mhz
It's broadly possible to sort any rule (or superset or subset of rules) into one of two different buckets:
One bucket contains the rules about the things things we're not allowed to do. Like a firewall with a blacklist, whereby we can do whatever we want that explicitly isn't blacklisted. It is allow-by-default.
The other bucket contains the rules about things that we are permitted to do. This is like a firewall with a whitelist, where we can do whatever the whitelist explicitly allows us to do and nothing more. It is deny-by-default.
Drug laws in the USA are in the first bucket (blacklisting). Radio transmission rules in the USA are in the second bucket (whitelisting).
(There is no third bucket.)
Then there are laws that prohibit things like broadcasting radio signals without a license.
Then within those very same laws there are exceptions allowing certain transmissions WITHOUT a license, in specific circumstances.
The "default" is that things are legal unless they are made illegal, and I think it's pointless wordplay to try to argue the default state is somehow the law prohibiting unlicensed operation, and not the part of those same laws that allow unlicensed operation in particular bands with particular transmission power limits.
I understand the point you're trying to make that some parts of U.S. law say that all not-explicitly-mentioned radio transmissions are unlawful, but that's not meaningfully different from drug policies that say that all "harmful substances" are unlawful and so forth. They all just boil down to what the law defines as being within its own scope.
And in the United States of America, at least: Radio transmissions are illegal by law, except where permission is granted by law.
(Try not to overthink it too much. A previous responder provided a citation that did not serve them well.
This situation can seem ugly or fantastic or jubilant or something else -- and it can be changed! -- but it still is just is how it is.)
I can grow my own food. I can share it with my neighbors. In Ohio, at least, I can sell a ton of produce every day to random strangers at any price that we find to be mutually acceptable, and I can do this without any licensing, inspection, or sales tax burden.
But I don't grow much of my own food; I never wanted to grow up to be a farmer.
I mostly consume products of industrialized agriculture. The USDA, FDA, and FTC help to ensure that the national brands I buy from the grocery store contain what they say they do, and that they're safe to consume, and that I get something close to the amount of it that is printed on the label.
When I buy a 5-pound bag of wheat flour from the grocery store today it weighs in at right around 5 pounds and is made from wheat. Yeah, there's some stragglers from other plants in the process and a completely non-zero number of insect parts and stuff, but it's not like there's a special department that grows bugs just to throw them into the mix. The goal is to simply produce and deliver wheat flour.
There was a time when adulteration and substitution of food was common and deliberate. We used to bulk up flour using cheap minerals that we'd dig out of the ground that had zero nutrition, such as gypsum. This kind of thing serves as proof that companies are assholes when left to their own devices.
I guess we could go back to letting them do just fucking-whatever again, but do you really want to have to analyze all of the food that you buy in order to gain knowledge of what's actually in there? (How else would you be able to make an informed purchasing decision?)
Anyway, that sounds like a ton of work compared to paying a little extra to have other people do it for me, whereby I can just read the ingredients label and know with pretty good surety what's inside the bag.
I live in a society. I make money doing things that I'm good at doing, and I use this money to pay people to do stuff that they're good at doing -- and to make sure that they're doing it right.
That would be illegal regardless? Please note my earlier up front acknowledgement that these areas of society do indeed appear to require some amount of regulation. I never presented an argument for a laissez-faire approach.
> I can grow my own food. I can share it with my neighbors. In Ohio, at least, I can sell a ton of produce every day to random strangers ...
If you look into it more deeply I believe you will find that your mileage varies in some surprising and offensive ways.
> The USDA, FDA, and FTC help to ensure that the national brands I buy from the grocery store contain what they say they do, and that they're safe to consume ...
Certainly they do. (I never disputed the need for this BTW. In fact I explicitly acknowledged it. Are you sure you're actually responding to what I wrote? Like at all?) Although since you brought it up I'll point out that they also fail in a number of ways. Consider for example the long standing failure of the FDA to competently audit the composition of "supplements". Or recall that time that the consumers bringing a lawsuit for false advertising over "real juice" lost. If you simply ignore all the gaps then sure it can be made to look like we do a great job in the US.
> I guess we could go back to letting them do just fucking-whatever again ...
Yeah nowhere did I suggest that. The opinion that regulation of the commercial food supply is necessary and the opinion that the FDA as it currently stands is a flaming pile of shit aren't mutually exclusive.
(If they happen to be reading I'd like to offer a hearty fuck you to whoever at Intel and Qualcomm initially decided on these absurd policies.)
Prologue. We get it, GP hates the u.s.-centric view. Found on this american website.
https://www.zoobab.com/zooland
For the same reason, those regulations (FCC radio lockdown etc) stifle innovation in the SDR world.
So: the optimal regulatory approach changed, the laws didn't keep up, and now we have suboptimal regulation that isn't bad enough to spur a fix and vested interests (spectrum owners) who don't want it fixed so I expect it to continue for a very long time. So it goes. It's not great but if all the world's problems were as small as this one it would be a much nicer place.
(This is why you will never truly own your smartphone, even though you paid for every chip inside it)
We treat RF like your lot treat Mexican fireworks.
They are not required to be as secure as credit card chips, but they also can't be wide open.
https://espargos.net/espsdr/ straight up shows its an ADC/DAC debug interface working both ways.
You don't need much to spam random RF energy into the air. That project just flips a GPIO pin at the right frequency, and gets a signal into the air.
It won't be very powerful, and the harmonics will probably bleed all over the place if you just hang a wire off of it with no filters.....
Actual FCC licensed products are supposed to not be naughty. But nothing prevents components from being naughty.
Inside ISM bands there are rules but beyond that anything goes.
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.
>compresses to about 1.2 bytes per pair, around 95–100 MB/s
No mention what FPGA platform/board used, FT600 USB chip is ~$10 alone.
Now you can replace all of it with one of those silly $5 FX2LP USB 2.0 dev boards. CY7C68013A-56 supports 16bit interface and will happily pump 30MB/s all day long for a fraction of the price. $10 total for 2.4GHz ~12MSPS@10-Bit SDR.
> 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.
I recently got interesed in hobby electronics again and happened to lookup what I can do with an ESP32 -- and since then there has been at least one HN front page post about ESP32 every day. Not sure if it is just a frequency illusion.
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.
I have a couple of Kanga Finningley SDRs bought through the G-QRP club, but they appear to have almost entirely vanished from the Internet.
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.