mirror
/
robot36
kopia lustrzana https://github.com/xdsopl/robot36
1
0
Forkuj 0
Kod Zgłoszenia Projekty Wydania Wiki Aktywność

tested aspell on README, works good.

master
Ahmet İnan 2011-10-25 23:41:22 +02:00
rodzic ab7d041f64
commit 6646caec89
1 zmienionych plików z 4 dodań i 4 usunięć
Pokaż statystyki Ściągnij plik aktualizacji Ściągnij plik porównania Expand all files Collapse all files

8
README
Wyświetl plik

@ -11,7 +11,7 @@ Theory of operation:
Robot 36 is one mode of many SSTV modes which transfers images using the luminance / chrominance information of the image.
Like with other SSTV modes, the information is send using FM and needs only 800hz bandwidth for data (1500hz-2300hz) and 200hz for control (1100hz-1300hz).
Robot 36 transfers 320x240 color images in around 36 seconds, hence the name Robot 36.
More information about Robot 36 mode and SSTV can be found on the internet.
More information about Robot 36 mode and SSTV can be found on the Internet.
I suggest finding and reading the wonderful "Dayton Paper" of JL Barber (N7CXI).
encode:
@ -21,7 +21,7 @@ decode:
FM demodulation is not so easy. After many frustrating attempts to emulate hardware and playing around with zero cross detection and Phase-locked loop detectors i finally found a very nice way to do it:
Using Hilbert Transformation we get a complex valued function from a real valued function, which we differentiate in time using polar coordinates and getting the instantaneous frequency from the argument.
Doing Hilbert Transform in discrete space for this purpose is also know as Digital Down Conversion.
my DDC consists of an complex valued decimating ideal fir filter using Kaiser window at its input and an complex oscilator mixer at its output.
my DDC consists of an complex valued decimating ideal fir filter using Kaiser window at its input and an complex oscillator mixer at its output.
You can find a lot more about DDC's and FM demodulation on the Internet.
I Suggest finding and reading the enlightening "Virtual Radios" Paper of Vanu Bose, Michael Ismert, Matt Welborn, and John Guttag.
You should also look at GNU Radio: http://gnuradio.org/ and at the invaluable information at dspGuru: http://www.dspguru.com/
@ -37,10 +37,10 @@ test encode and decode using smpte.ppm and various rates:
remove generated files:
# make clean
listen to default alsa device and write out ppm images with %F-%T.ppm as filename:
listen to default alsa device and write out ppm images with %F-%T.ppm as file name:
# ./decode
listen to alsa device plughw:0,0 and write out ppm images with %F-%T.ppm as filename:
listen to alsa device plughw:0,0 and write out ppm images with %F-%T.ppm as file name:
# ./decode plughw:0,0
listen to default alsa device and show image in sdl window: