Hi,
I am having problems with the gain-settings on the RX-channels of usrp1
My USRP1 is populated with 2 LFRX and 2 LFTX.
I want to use 2 DDC-channels each connect to one 2 ADC of LF-RX-Board A.
I have generated the following code with grc.
When apply a signal of roughly 11MHz I see the mixed signals on each
scope.
The relation to the inputs is o.k.
The gain-settings are however not as I expect:
self.uhd_usrp_source_0.set_gain(6, 1) affects both channels while
self.uhd_usrp_source_0.set_gain(6, 0 has no effect.
From what I rememeber that was different in the pre-uhd-times.
Any hint, on how I can set the gains for both channels independently?
Thanks
Wolfgang
#!/usr/bin/env python
##################################################
Gnuradio Python Flow Graph
Title: Top Block
Generated: Wed May 29 18:17:11 2013
##################################################
from gnuradio import eng_notation
from gnuradio import gr
from gnuradio import uhd
from gnuradio.eng_option import eng_option
from gnuradio.gr import firdes
from gnuradio.wxgui import scopesink2
from grc_gnuradio import wxgui as grc_wxgui
from optparse import OptionParser
import wx
class top_block(grc_wxgui.top_block_gui):
def __init__(self):
grc_wxgui.top_block_gui.__init__(self, title="Top
Block")
_icon_path =
“/usr/share/icons/hicolor/32x32/apps/gnuradio-grc.png”
self.SetIcon(wx.Icon(_icon_path, wx.BITMAP_TYPE_ANY))
##################################################
# Variables
##################################################
self.samp_rate = samp_rate = 500000
##################################################
# Blocks
##################################################
self.wxgui_scopesink2_0_0 = scopesink2.scope_sink_c(
self.GetWin(),
title="Scope Plot1",
sample_rate=samp_rate,
v_scale=0,
v_offset=0,
t_scale=4e-6,
ac_couple=True,
xy_mode=False,
num_inputs=1,
trig_mode=gr.gr_TRIG_MODE_NORM,
y_axis_label="Counts",
)
self.Add(self.wxgui_scopesink2_0_0.win)
self.wxgui_scopesink2_0 = scopesink2.scope_sink_c(
self.GetWin(),
title="Scope Plot0",
sample_rate=samp_rate,
v_scale=0,
v_offset=0,
t_scale=4e-6,
ac_couple=True,
xy_mode=False,
num_inputs=1,
trig_mode=gr.gr_TRIG_MODE_NORM,
y_axis_label="Counts",
)
self.Add(self.wxgui_scopesink2_0.win)
self.uhd_usrp_source_0 = uhd.usrp_source(
device_addr="serial=47432785",
stream_args=uhd.stream_args(
cpu_format="fc32",
channels=range(2),
),
)
self.uhd_usrp_source_0.set_clock_source("gpsdo", 0)
self.uhd_usrp_source_0.set_time_source("gpsdo", 0)
self.uhd_usrp_source_0.set_subdev_spec("A:A A:B", 0)
self.uhd_usrp_source_0.set_samp_rate(samp_rate)
self.uhd_usrp_source_0.set_center_freq(11e6, 0)
self.uhd_usrp_source_0.set_gain(0, 0)
self.uhd_usrp_source_0.set_center_freq(11e6, 1)
self.uhd_usrp_source_0.set_gain(6, 1)
##################################################
# Connections
##################################################
self.connect((self.uhd_usrp_source_0, 0),
(self.wxgui_scopesink2_0, 0))
self.connect((self.uhd_usrp_source_0, 1),
(self.wxgui_scopesink2_0_0, 0))
def get_samp_rate(self):
return self.samp_rate
def set_samp_rate(self, samp_rate):
self.samp_rate = samp_rate
self.wxgui_scopesink2_0_0.set_sample_rate(self.samp_rate)
self.wxgui_scopesink2_0.set_sample_rate(self.samp_rate)
self.uhd_usrp_source_0.set_samp_rate(self.samp_rate)
if name == ‘main’:
parser = OptionParser(option_class=eng_option, usage="%prog:
[options]")
(options, args) = parser.parse_args()
tb = top_block()
tb.Run(True)