Turn a WiFi 7 Router into a 320Msps Software Defined Radio Receiver (github.com)

207 points by djfergus 9 hours ago

yonatan8070 4 hours ago

This same devloper also built an SDR out of an ESP32 Wi-Fi microcontroller [1], this is awesome!

This development makes me hope that we'd be seeing more of these on common Wi-Fi cards, so that every random laptop could be used as an SDR for many fun and useful applications on a budget.

https://github.com/h0m3us3r/eSpDR

dzhiurgis 16 minutes ago

I was really excited about this, but as an average home assistant user couldn't really see an application, lol.

thebeardisred 4 hours ago

FYI, since it's the same chipset I'm pretty certain this will work on the Banana Pi R4, which has built in PCIe for NVMe.

alightsoul an hour ago

Is this kind of thing why samsung asks you to sign a contract before letting third parties use the FM radios on their phones? Because many phone radios nowadays are software defined?

askvictor 20 minutes ago

Which phones still have FM radios?

mikewarot 4 hours ago

Having done repairs on a ton of older service monitors, and having my hand in SDR, this is amazing! There's a huge amount of machining and hardware to make a service monitor, but with desktop CNC, cheap PCBS, and jelly bean components that go into the 10s of GHz, the sky's the limit.

I'd add a heat sunk 100 watt DC-5Ghz 20dB fixed attenuator, 0-110 dB switched attenuator, 5 ghz low pass filter, 7-12 Ghz local oscillator/mixer up/down converter, and it would make a small, very high performance service monitor good to 5 Ghz. 8)

Eduard 2 hours ago

Service monitor?

mikewarot an hour ago

A Communications service monitor is a tool for servicing radios. Until recently, most large organizations used VHF/UHF FM radio for communications on dedicated channels. A service monitor is a tool that can usually absorb the full output power of these radios while measuring power, frequency, distortion, etc. They can also generate a variety of signals for aligning receivers.

Most of the older, affordable models go from almost DC to 1 Ghz. I've got an IFR 2947a, which goes up to 1.05 Ghz.

Here's an example from ebay.

https://www.ebay.com/itm/168770412399

Here's a specification sheet for the one I have, a pdf

https://www.testmart.com/webdata/mfr_pdfs/aerofl/2947a.pdf

octoberfranklin 3 hours ago

Why 4ghz?

mikewarot 3 hours ago

I've edited it, but generally you don't want to have problems with mirror images getting through and creating spurious responses. Real world RF filters don't have infinitely steep edges, so initially I figured a 4 Ghz low pass filter would have enough loss by 5 Ghz to get the job done. I revised to to a 5 Ghz low filter, and a 7-12 Ghz Local Oscillator to give the filter an easier job. Also, the lower the swing in percentage terms for a VCO, the easier it is to work with.

So the signal path in receive mode would be:

N connector / 20 dB 100 watt pad / Switched attenuator / Low pass filter / Front End diodes / Mixer / Router board for DSP

Alternatively, there's usually a second path that skips the attenuator, with a lower maximum power level.

The reverse path would work for generating signals from DC (almost) to 5 Ghz.

aftbit 5 hours ago

Wow that's super cool! It's not DC to daylight but I sure don't know a cheaper way to get a 320 Msps receiver at 5 GHz.

asdff 5 hours ago

Thanks claude

ChuckMcM 5 hours ago

Yeah, reading stuff like:

"BRINGUP, from a cold radio: what MediaTek's ROM patch does at download (XO, pin mux, the CONN AFE calibration pulse per band, the A-die TOP init by chip ID, pads and CONN switch, the A-dies' eFuse trims); the UMAC pool layout; the common and per-band PHY initialisation; on each A-die the RF init tables, the resistor calibration and the RC filter calibration; the FEM outputs and the crystal trim."

That's not even some other language poorly translated to English, that's just a bunch of words.

Between stuff like this and math "proofs" that aren't readable either I'm really challenged to see the benefit here.

What I get out of this is that one could, if you had the documentation, write a more generalized SDR application for this hardware than the Wifi7 application. That an LLM model can provoke this behavior seems as a good existence proof perhaps?

Aurornis 4 hours ago

> That's not even some other language poorly translated to English, that's just a bunch of words.

The language makes sense if you've worked with radio chips or firmware.

Terms like XO (crystal oscillator) and pin mux (chip pin multiplexer, basically assigning pins to their role) are common for embedded work, not just radio work.

Usually in a project you get that language hidden in a separate implementation doc where casual readers won't get confused by it.

ChuckMcM 4 hours ago

NitpickLawyer 4 hours ago

> I'm really challenged to see the benefit here.

> write a more generalized SDR application for this hardware

Yeahhh, no. Sorry but the entry barrier is now extremely lowered, especially in effort.

~20 years ago this would have been literally sci-fi. Back then just getting an USRP to work with gnu-radio, then finding the proper hardware external clock, then doing lots of work on reading / trying stuff / writing scripts etc. took a ton of effort and time. Having the ability to throw tokens at it and have at least a starting point is amazing, IMO.

Aurornis 4 hours ago

If someone wants to set up some hardware in a harness and then spend their tokens reverse engineering it, I'm thankful for the publication.

A year ago it was different. I looked at a lot of these vibe-RE projects and a lot of them wouldn't even do what they claimed. Now if someone points a frontier model at some code and lets it consume tokens for a few days, the output is often valuable as a starting point for other projects.

ctmlr an hour ago

Try using GPT to write software like this, I don't think just anyone could do it unless they know the problem domain well. Understanding something is not something any AI can replace (yet).

BlackRabbit1 5 hours ago

Claude or not: It's a huge breakthrough for ham radio and signal analysis.

We now can programm more manual tuned stuff to turn this into a full 13cm and 5cm radio as it was proven to work.

Before the esp-sdr hack and this one both bands were quite difficult and pricey to reach.

jeffbee 4 hours ago

Why is this a breakthrough? Just because the platform costs under $100?

BlackRabbit1 4 hours ago

radio879 4 hours ago

I can't keep up with the rapid, non stop cool stuff being discovered! Someone figured out how to get the ESP32 to transmit, at lower bandwidth (I think I read 200-250khz) I don't know which project it was but there are a bunch on this site:

https://www.rtl-sdr.com/esp32-sdr-turbo-mode-throughput-impr...

mikewarot 3 hours ago

Holy cow... I've got to limit my projects, so I don't repeat history where I kept finding radio shack bags full of parts for ideas. But you can get 3 of those, with external antennas for less than $60 through amazon. I put it in my wish list instead of buying them now. I've got a data diode to finish first.

Sideband on 13 CM sounds like an amazing thing to pull off.

acd 4 hours ago

What is the radio quality like SNR?

BlackRabbit1 4 hours ago

I'd assume top notch if it's Wi-Fi certified. And basically all Mediatek modems are.

You cannot sell them with the tag if it wasn't connected to standardized certification test system at least once.

zdw 3 hours ago

$80 here? https://www.amazon.com/dp/B0DR7KMNC4

That's quite a good deal...

tverbeure 2 hours ago

Yeah, mine is arriving tomorrow, because I totally needed another unused SDR platform.

jedbrooke 4 hours ago

wow, could this be turned into a 2.4ghz SAR? I always wondered if it’d be possible to use something like that to pick up wifi signals from much farther away. Of course a more sensible choice would just be to use a yagi antenna

octoberfranklin 4 hours ago

It's RX-only.

BlackRabbit1 4 hours ago

Yet.

octoberfranklin 3 hours ago

sigbottle 3 hours ago

What do normal people use SDRs for? I'm genuinely curious. Or is it just cool to do?

SyzygyRhythm an hour ago

At the moment I have 5x RTL-SDR dongles streaming into a box on different bands (137, 433, 912, 978, and 1090 MHz). They pick up all kinds of things, from local weather stations to the water meter for my condo to ADS-B/UAT transmissions from local aircraft. I even see the tire pressure monitor signals from cars that drive by (some of you guys need to add air!).

Mostly it's just fun. I like peeking at all the ambient transmissions in the area.

A while back I was more deeply involved in the SDR space and even reverse-engineered some pager signals. At least a few years ago, pagers were still widely used in hospitals (totally in plaintext, by the way).

bb88 2 hours ago

It is cool to do. But there are professional uses for it, particularly like finding interference or noise. You can ask things like: "How crowded is my 2.4 GHz spectrum?"

The RTL SDR is the gateway drug into SDR's. The bandwidth is limited, so don't expect to be capturing HDTV Streams. But it's certainly possible to listen to AM/FM, Ham Bands, VHF/UHF signals, etc.

If you don't want to buy an RTL-SDR, you can search KiwiSDR which is a streaming SDR for frequencies under 30MHz. You can also connect to KiwiSDR's worldwide.

Then if you get the itch, you can go get your a HackRF, a ham license, or whatever else scratches it.

dekhn 3 hours ago

I've used it to identify transmissions in my neighborhood in the public (ISM) band, listen to various radio broadcasts outside the normal AM/FM, and best of all, track all the planes in my area (ADS-B).

BlackRabbit1 2 hours ago

Satdump group uses them receiving all kind of weather satellites. They are mastering S-/X-Band stuff for ages already.

Ham radio operators looking forward using them for 13cm and 5cm band stuff.

jeffbee 5 hours ago

An accurate description is "turn an SDR into an SDR".

yonatan8070 3 hours ago

More like "turn a locked-down single-purpose SDR into a general-purpose SDR"

flemhans 4 hours ago

Anyone know how to get ahold of a device in Europe?

criddell 3 hours ago

Can you order them from amazon.com? I've ordered stuff from amazon.co.jp and amazon.de before and although it doesn't get there in two days, it does show up eventually.

jauntywundrkind 2 hours ago

Super awesome.

Not the point but the Airhona could here is really neat. AN7581 with typical quad Cortex-A53 but then 8x RISC-V network coprocessors. Good luck figuring out how to use that though, whew! (Go Astra go.) https://www.airoha.com/products/p/NpfqGLnZiZuYUZ6N

I've been thinking how beautiful and awesome it is that SDR finally has a real jump. The QuadRF using the rpi's mipi connector was such a glorious hack! Custom ADC from parts. 80MSps. https://www.crowdsupply.com/scale-rf/quadrf

And man what a huge flying leap forward here. 320MSps! Much deeper 14b IQ precision vs 8b. The totally custom mediatek radio firmware is incredible. Such incredible possibility. Maybe someday the mimo can be useful for some of the same neat AoE / beam forming capabilities?

yieldcrv 3 hours ago

Am I understanding that this is doing something the chipset wasn’t designed to do?

I’m not seeing a synopsis of the significance of this, for the uninitiated

What is Msps? I’m not familiar with that scale

BlackRabbit1 3 hours ago

> Am I understanding that this is doing something the chipset wasn’t designed to do?

Every WiFi modem has a testmode. It's required to verify the TX/RX chain during manufacturing and for compliance testing.

Seemingly you can read out the entire spectrum at full rate.

tverbeure 3 hours ago

mega samples per second. IOW: sample rate.

The significance is that most off the shelf SDR platforms have much lower specs. Almost all of them use the same Analog Devices transceiver chip.

crest 3 hours ago

Msps = Mega samples per second

crest 3 hours ago

Now if you could also make it transmit such samples a few of those could make a nice DIY phase array for some of the most fun bands to play with.