[ath9k-devel] Spectral Scan in ath9k

[Gui Iribarren <gui@altermundi.net>]

On 05/08/2013 07:50 PM, Oleksij Rempel wrote:
> Am 08.05.2013 18:15, schrieb Claudio:
>> Hi all,
>>    first of all thank you for the code you have developed.

Indeed, it opens the door to many interesting possibilities!
Thanks a lot Simon and Mathias for letting the genie out of the bottle, 
and Adrian, Felix, Zefir for helping its way out :P

I finally got to play with Simon's code and it works better than i expected
http://blog.altermundi.net/article/playing-with-ath9k-spectral-scan/

>> echo chanscan > /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan_ctl
>> iw dev wlan0 scan
>> cat /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan0 > /tmp/fft_resusts
>> ./fft_eval /tmp/fft_results
>>
>> On average I get 200-400 samples but sometimes I got even 7k samples, which
>> is very good.

In my case i get a fairly constant 112 samples per "iw wlan0 scan", but 
as always, YMMV.

maybe something is triggering periodic scans on your hardware? (i.e. a 
STA wifi-iface in OpenWrt does this every 2 or 3 seconds until it 
associates to an AP). In that case, just idling between "cat 
spectral_scan"s will increase the number of samples.
Try running "iw event" in parallel to see what's happening.

Cheers and have spectral fun!!

Gui