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Turn a WiFi 7 Router into a 320Msps Software Defined Radio Receiver

117 points6 hoursgithub.com
thebeardisred • 2 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.

octoberfranklin • 47 minutes ago

[flagged]

tuckerpo • 44 minutes ago

mt7996 is MTK

yonatan8070 • 2 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

sigbottle • 17 minutes ago

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

dekhn • 13 minutes 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).

aftbit • 3 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.

mikewarot • 2 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)

octoberfranklin • 50 minutes ago

Why 4ghz?

mikewarot • 24 minutes 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.

radio879 • 1 hour 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...

asdff • 2 hours ago

Thanks claude

ChuckMcM • 2 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 • 2 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 • 1 hour ago

Yes there are radio terms in there. :-) That said, I've written combined firmware/gateware drivers for dedicated radio chips and that paragraph makes little sense to me. Even the RFSoC docs from AMD/Xilinx are better written and they are pretty damn dense.

Aurornis • 1 hour ago

> Even the RFSoC docs from AMD/Xilinx are better written

This project isn't meant to be vendor-quality documentation of the chipset. It's a reverse engineering project that succeeded and included enough documentation to build upon.

Comparing a freely shared reverse engineering proof of concept to vendor-provided 1st party documentation is a ridiculous high bar.

This is a cool project that was just shared hours ago. Criticizing it for not being 1st party vendor documentation quality is a really bad faith criticism.

NitpickLawyer • 2 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 • 2 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.

BlackRabbit1 • 2 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 • 2 hours ago

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

BlackRabbit1 • 2 hours ago

320MSPS at this frequencies for less than $100 that can be extracted over 10GBit/s.

This was worth upper 4- to 5-digit of dollars of equipment before.

I work in this industry and sold more than one kidney for this stuff.

Same for the ESP-SDR project. Most likely it can be used for transmitting on S-Band for satellite control in the future (with an amplifier, dish, maybe some filtering). The HF-Frontend is Wi-Fi certified and therefore quite clean. I've forwarded this project to a friend who's close to ESA staff.

+1
jeffbee • 2 hours ago
jedbrooke • 2 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 • 1 hour ago

It's RX-only.

BlackRabbit1 • 1 hour ago

Yet.

octoberfranklin • 49 minutes ago

Ssshhh. Don't wake the FCC.

acd • 2 hours ago

What is the radio quality like SNR?

BlackRabbit1 • 2 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.

flemhans • 1 hour ago

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

criddell • 26 minutes 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.

yieldcrv • 47 minutes 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 • 30 minutes 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 • 41 minutes 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 • 44 minutes ago

Msps = Mega samples per second

jeffbee • 2 hours ago

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

yonatan8070 • 42 minutes ago

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

crest • 44 minutes 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.