Brett, here there is how I made it work on my install:
1) create a tmpfs on linux by adding this mount point to /etc/fstab:
ramfs /mnt/ramfs tmpfs defaults 0 0
2) mount the new ram file system "mount ramfs"
3) create a pipe with the command "mkfifo /mnt/ramfs/drm.raw"
4) attach the standard drm to the pipe: "drm --fileio /mnt/ramfs/drm.raw"
5) start drm.py with the correct frequency (see drm.py -help)
here follows the drm.py code:
#!/usr/bin/env python
from gnuradio import gr
from gnuradio import usrp
from math import pi
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from gnuradio.wxgui import stdgui, scopesink, fftsink
from optparse import OptionParser
import wx
class app_flow_graph (stdgui.gui_flow_graph):
def __init__(self, frame, panel, vbox, argv):
stdgui.gui_flow_graph.__init__ (self, frame, panel, vbox, argv)
parser = OptionParser(option_class=eng_option)
parser.add_option("-f", "--freq", type="eng_float", default=5990e3,
help="set frequency to FREQ", metavar="FREQ")
parser.add_option("-g", "--gain", type="int", default=10,
help="set gain in dB (default is midpoint)")
(options, args) = parser.parse_args()
if len(args) != 0:
parser.print_help()
sys.exit(1)
adc_rate = 64e6
usrp_decim = 148
if_rate = adc_rate / usrp_decim
if_decim = 9
demod_rate = if_rate / if_decim #48048.048
src = usrp.source_c (0, usrp_decim)
src.set_rx_freq (0, -options.freq+7e3)
actual_freq = src.rx_freq(0)
src.set_pga(0,options.gain)
print "FREQ: ",actual_freq
print "Gain: ",options.gain
channel_coeffs = \
gr.firdes.low_pass (if_decim, # gain
if_rate, # sampling rate
14e3, # low pass cutoff freq
3e3, # width of trans. band
gr.firdes.WIN_HANN)
dec = gr.fir_filter_ccf(if_decim,channel_coeffs)
vc = gr.multiply_const_cc(10)
print "len(channel_coeffs) =", len(channel_coeffs)
fft, win = fftsink.make_fft_sink_c (self, panel, "Spectrum", 512,
demod_rate)
vbox.Add (win, 1, wx.EXPAND)
c2r = gr.complex_to_real()
r2s = gr.float_to_short()
out = gr.file_sink(gr.sizeof_short,"/mnt/ramfs/drm.raw")
# now wire it all together
self.connect (src, dec)
self.connect (dec, vc)
self.connect (dec,fft)
self.connect (vc,c2r,r2s,out)
def main():
app = stdgui.stdapp (app_flow_graph, "Spectrum Analyzer")
app.MainLoop ()
if __name__ == '__main__':
main()
> Apparently, a forked version of DRM using lower bandwidth codecs has
> been developed- originally called Hamdream by HB9TLK and was GUI-fied by
> N1SU and called WinDream. This particular version uses different codecs
> and supports two-way mode.
>
> It seems like this version would be more directly aimed at USRP/GNURadio
> users, though support for 'official' DRM would be obviously beneficial
> as well!
>
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> Discuss-gnuradio@gnu.org
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>
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