[HN Gopher] Use the WiFi Chip on RaspberryPi/Broadcom as Softwar...
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       Use the WiFi Chip on RaspberryPi/Broadcom as Software-Defined Radio
       (SDR)
        
       Author : punnerud
       Score  : 126 points
       Date   : 2021-05-15 07:56 UTC (15 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | peterburkimsher wrote:
       | It's an SDR transmitter, not receiver.
       | 
       | Pity that the bands are still limited to 2.4 and 5 GHz WiFi.
       | 
       | For GPS [1] or cellular [2] spoofing, osmo-fl2k may be a better
       | option. In practice though, I've only used my MAIWO KCB003 for
       | that once, as a demo. It's quite inconvenient to set up the
       | flowgraph on an Ubuntu VM, generate 20 GB of samples, and then
       | stream it from my Mac. Better software would make this much
       | easier to use.
       | 
       | I use a MAIWO KCB003, for portability. It's not very good as a
       | USB-VGA adaptor though, because it needs custom drivers to be
       | installed. When the guest speaker needs to plug their laptop into
       | a projector, they don't have time to install drivers.
       | 
       | [1] https://hackernoon.com/osmo-fl2k-a-15-dtv-transmitter-fm-
       | rad...
       | 
       | [2] https://hackaday.com/2018/04/23/spoofing-cell-networks-
       | with-...
        
         | franga2000 wrote:
         | The fl2k is awesome and I really wish much more would've
         | developed around it. I guess anyone who knows enough about DSP
         | likely already has a better radio, especially when things like
         | the HackRF exist.
        
       | causality0 wrote:
       | Is there some secret to getting a Pi at MSRP or is it just
       | another victim of the semiconductor shortage? I can't find a Pi
       | Zero W for under $20 or a Pi 4 for under $50.
        
         | gkhartman wrote:
         | I've heard that Microcenter is a good option. They seem to be
         | the best bet right now for things like GPUs if you go on the
         | right day (with a bit of luck).
        
         | kingosticks wrote:
         | Stock and prices are fine here in the UK right now.
        
         | II2II wrote:
         | Check out the dealers on the Raspberry Pi website. A few of the
         | dealers have them in stock and they appear to be close to MSRP.
         | (I'm waiting on a 4 GB unit that was about US$56, compared to
         | US$55 MSRP. The 2 GB units at US$35 are listed as well.)
        
       | anonymousDan wrote:
       | Is it possible to get a workeable sdr that can send and receive
       | for $100-200 these days? If so what frequency bands would it
       | support?
        
       | drno123 wrote:
       | Publish or perish license - if you use the code in your research,
       | you MUST cite their paper.
        
         | zenexer wrote:
         | It's a pretty interesting license.
         | 
         | > The Software is not used by, in cooperation with, or on
         | behalf of any armed forces, intelligence agencies,
         | reconnaissance agencies, defense agencies, offense agencies or
         | any supplier, contractor, or research associated.
        
           | Siira wrote:
           | It's not FOSS.
        
             | generalizations wrote:
             | Honestly? This is _hacker_ news. If it does what I need, I
             | 'll use it.
        
           | Muromec wrote:
           | It's a nice message, but it's not like any of entities listed
           | above would just pass by and not use such a thing.
        
       | inetknght wrote:
       | > _This projects demonstrates our discovery that turns Broadcom
       | 's 802.11ac Wi-Fi chips into software-defined radios that
       | transmit arbitrary signals in the Wi-Fi bands._
       | 
       | But... what about receive?
        
       | bitwize wrote:
       | This is why Broadcom chips come with proprietary blobs: the FCC
       | and corresponding regulatory bodies elsewhere would never approve
       | them if they had open source firmware or were fully documented.
        
         | vineyardmike wrote:
         | Source? This seems unlikely considering the existence of legal
         | SDR.
         | 
         | Also proprietary blobs seem like a whole separate thing that
         | companies would do to protect IP.
        
           | generalizations wrote:
           | Can confirm. Look at the FCC regulations for selling rf-
           | emitting devices. The seller has to show that the device will
           | only emit at the specified frequencies and power. When it's
           | consumer-facing, like a wifi router, one way to do that when
           | the hardware itself is technically capable of more, is to
           | lock down the firmware.
           | 
           | The downvotes on gp are misinformed.
        
             | monocasa wrote:
             | These chips and their closed blobs are older than the
             | relevant FCC regulation.
        
         | grishka wrote:
         | I've seen this same argument about cellular modems too, and
         | that, too, has never prevented people from reverse engineering
         | them.
        
       | Semaphor wrote:
       | Originally posted around release 2018 (60 comments):
       | https://news.ycombinator.com/item?id=16589703
        
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       (page generated 2021-05-15 23:00 UTC)