Two interesting things I saw when listening to the output from my microwave:

  1. The frequency is not stable. I assume it’s not thermally controlled.
  2. Probably not a good idea to use WiFi channel 6, being 2.437GHz+-11MHz and all.

Near the microwave

Near the microwave

Some rooms away from the microwave

Separate measurement some rooms away.

Further from microwave

How to generate the graphs

# Edit usrp_spectrum_sense.py so that it prints time.time() instead of datetime.now()
./usrp_spectrum_sense.py --dwell-delay=0.1 -A RX2 -s 8000000 --real-time 2.4e9 2.5e9 > near-microwave.txt
# Edit near-microwave to remove the stupid verbose messages from the top.
cat > microwave.plot << EOF
set view map
set size ratio .9

set object 1 rect from graph 0, graph 0 to graph 1, graph 1 back
set object 1 rect fc rgb "black" fillstyle solid 1.0

set xlabel 'Time in seconds'
set ylabel 'Frequency'
set zlabel 'dB'
set terminal epslatex color
set output "near-microwave.eps"
splot 'near-microwave.txt' using ($1-1496693552.11):((($5/1000-2400000)/1000)):4 with points pointtype 5 pointsize 3 palette linewidth 30 title 'Signal'
EOF
gnuplot microwave.plot
convert near-microwave.{eps,png}

I can’t have GNUPlot output PNG directly because it hangs.

The magic value 1496693552.11 is the first timestamp in the file.