- Target version changed from 0.13.0 to 0.12.0
- Status changed from New to In Progress
- % Done changed from 0 to 10
- % Done changed from 10 to 40
Making progress. I've got a Cairo based display showing which channels are in use and by how many networks. Now I want to graph the signal strength. To do this I need to run this command:
$ iw dev wlan0 scan
BSS 10:6f:3f:e7:24:55(on wlp3s0) -- associated
TSF: 797749164512 usec (9d, 05:35:49)
beacon interval: 100 TUs
capability: ESS Privacy (0x0011)
signal: -62.00 dBm
last seen: 82272 ms ago
Information elements from Probe Response frame:
Supported rates: 6.0* 9.0 12.0* 18.0 24.0* 36.0 48.0 54.0
DS Parameter set: channel 40
So look for the BSS in the first colmn to find a new entry. Then parse out the signal strength, SSID and channel. That's good enough to start. I can graph the signal and show the SSID with each graph.
Here is how you convert dBm to a percentage. It assumes a maximum dBm of -50, which seems about right from my laptop.
quality = 2 * (dBm + 100)
See this comment on serverfault. It mentions different dBm levels for different types of hardware. Basically, for PiBox if the dbm signal is -70 to -60 then the signal is good. So I could do a "yellow line" above which the BSS is good.
- % Done changed from 40 to 70
Graphing of wifi channels and signal strength is complete. Code is committed and pushed. Looks pretty good, actually. I select colors for the graphics using the golden ratio.
Now I need to add all 14 channels to the options menu for selecting a channel for the access point. Then I should set the default to 1, 6 or 11.
- Project changed from PiBox to pibox-network-config
- Category deleted (
09 - Testing)
- Status changed from In Progress to Closed
- % Done changed from 70 to 100
Done. All changes committed and pushed.
One additional note:
I swapped out all the ModMyPi dongles with the various Panda wifi dongles and things got much better. I also moved the RPI2 away from its USB hub just a bit. Maybe that's what I really needed: better dongles and less interference from the Pi.
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