Houston, we have a trunk.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@3122 221aa14e-8319-0410-a670-987f0aec2ac5

4 files changed, 762 insertions, 0 deletions

diff --git a/gnuradio-examples/python/multi_usrp/Makefile.am b/gnuradio-examples/python/multi_usrp/Makefile.am
new file mode 100644
index 000000000..c2c6a2943
--- /dev/null
+++ b/gnuradio-examples/python/multi_usrp/Makefile.am
@@ -0,0 +1,28 @@
+#
+# Copyright 2006 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+# 
+
+EXTRA_DIST = 			\
+	README		\
+	multi_usrp_oscope.py		\
+	multi_usrp_rx_cfile.py
+
+
+
diff --git a/gnuradio-examples/python/multi_usrp/README b/gnuradio-examples/python/multi_usrp/README
new file mode 100644
index 000000000..c93d7736a
--- /dev/null
+++ b/gnuradio-examples/python/multi_usrp/README
@@ -0,0 +1,260 @@
+Quick start multi-usrp:
+
+Unpack, build and install usrp, gnuradio-core and gr-usrp
+Versions need to be more recent then 2.7cvs/svn 11 may 2006
+
+Make sure usrp/fpga/rbf/rev2/multi*.rbf is installed in /usr/local/share/usrp/rev2/
+Make sure usrp/fpga/rbf/rev4/multi*.rbf is installed in /usr/local/share/usrp/rev4/
+(If in doubt, copy manually)
+ 
+build and install gr-wxgui gr-audio-xxx  and so on.
+
+unpack gnuradio-examples.
+
+There is a gnuradio-examples/python/multi_usrp directory which contains examples
+
+
+Put at least a basic RX or dbsrx board in RXA of the master and RXA of the slave board.
+Make sure that the usrps have a serial or unique identifier programmed in their eeprom.
+(All new rev 4.1 boards have this)
+You can do without a serial but then you never know which usrp is the master and which is the slave.
+
+
+CONNECTING THE CABLES
+Now connect the 64MHz clocks between the boards with a short sma coax cable.
+(See the wiki on how to enable clock-out and clock-in 
+http://comsec.com/wiki?USRPClockingNotes )
+
+You need one board with a clock out and one board with a clock in.
+
+You can choose any of the two boards as master or slave, this is not dependant on which board has the clock-out or in.
+In my experiments I had fewer problems when the board that has the clock-in will be the master board.
+
+You can use a standard 16-pole flatcable to connect tvrx, basic-rx or dbsrx boards.
+Of this 16pin flatcable only two pins are used (io15 and ground)
+For all new daughterboards which use up a lot of io pins you have to use a cable with fewer connections.
+The savest is using a 2pin headercable connected to io15,gnd (a cable like the ones used to connect frontpanel leds to the mainboard of a PC)
+
+If using basic rx board:
+  Connect a 16-pole flatcable from J25 on basicrx/dbs_rx in rxa of the master usrp to J25 on basicrx/dbsrx in RXA of the slave usrp
+  Don't twist the cable (Make sure the pin1 marker (red line on the flatcable) is on the same side of the connector (at io-8 on the master and at io8 on the slave.))
+  For basic_rx this means the marker should be on the side of the dboard with the sma connectors. 
+  For dbs_rx this means the marker should be on the side of the dboard with the two little chips.
+  In other words, don't twist the cable, you will burn your board if you do.
+
+You can also connect a flatcable with multiple connectors from master-J25 to slave1-J25 to slave2-J25 to ...
+You will however have to think of something to create a common 64Mhz clock for more then two usrps.
+
+For all other daughterboards, connect a 2wire cable from masterRXA J25 io15,gnd to slaveRXA J25 io15,gnd 
+
+
+So now the hardware is setup, software is setup. Lets do some tests.
+
+Connect power to both usrps.
+unpack the gnuradio_examples somewhere (cvs version later then 11 may 2006) 
+go to the gnuradio-examples/python/multi_usrp folder.
+
+Now run 
+ ./multi_usrp_oscope.py -x 12345678
+
+It should tell you that usrp 12345678 is not found and tell you which serials are available.
+
+Now run  ./multi_usrp_oscope.py -x actualserialnum 
+You should now get an oscope with two channels, one is from the master and one is from the slave
+It will which show the I-signal from channel 0 of the master usrp and I-signal from channel 0 of the slave usrp.
+(For testing connect the same signal source to the inputs of both boards)
+The signals should be aligned.
+If you click the sync button, it will resync the master and slave (should never be needed)
+
+Now run
+./multi_usrp_oscope.py --help
+To see all available options.
+
+
+Now you are ready to do phase-locked aligned signal processing.
+
+You can also capture to file with:
+./multi_usrp_rx_cfile.py 
+
+run ./multi_usrp_rx_cfile.py --help to see all available options.
+
+
+
+Here follows a description of the detail blocks used in usrp_multi.py
+
+Multi usrp
+
+With this code you can connect two or more usrps (with a locked clock) and get synchronised samples.
+You must connect a (flat)cable between a dboard on the master in RXA and a dboard on the slave in RXA.
+You then put one usrp in master mode, put the other in slave mode.
+
+The easiest thing to see how this works is just looking at the code in
+ multi_usrp_oscope.py
+ multi_usrp_rx_cfile.py 
+
+Use the usrp_multi block which is installed by gr-usrp.
+instantiate in the following way:
+
+        self.multi=usrp_multi.multi_source_align( fg=self, master_serialno=options.master_serialno, decim=options.decim, nchan=options.nchan )
+
+nchan should be 2 or 4.
+
+You determine which is the master by master_serialno (this is a text string a hexadecimal number).
+If you enter a serial number which is not found it will print the serial numbers which are available.
+If you give no serial number  (master_serialno=None), the code will pick a Master for you.
+
+You can get a reference to the master and the slave usrp in the following way:
+
+        self.um=self.multi.get_master_usrp()
+        self.us=self.multi.get_slave_usrp()
+
+You only need these references for setting freqs/gains or getting info about daughterboards.
+Don't use the output directly but use the aligned output from multi.get_master_source_c() and multi.get_slave_source_c()
+
+You get references to the aligned output samples in the following way:
+aligned_master_source_c=self.multi.get_master_source_c()
+aligned_slave_source_c=self.multi.get_slave_source_c()
+
+These blocks have multiple outputs.
+output 0 is the sample counter (high bits in I, low bits in Q)
+You normally don't need the samplecounters so you can ignore output 0
+
+output 1 is the first aligend output channel (if you enable 2 or 4 channels)
+output 2 is the second output channel (only if you enable 4 channels)
+
+so the usefull 4 channels are:
+self.aligned_master_chan1=(self.multi.get_master_source_c(),1)
+self.aligned_master_chan2=(self.multi.get_master_source_c(),2)
+self.aligned_slave_chan1=(self.multi.get_slave_source_c(),1)
+self.aligned_slave_chan2=(self.multi.get_slave_source_c(),2)
+
+The two samplecounters are:
+self.aligned_master_samplecounter=(self.multi.get_master_source_c(),0)
+self.aligned_slave_samplecounter=(self.multi.get_slave_source_c(),0)
+
+You can set the gain or tune the frequency for all 4 receive daughetrboards at once:
+        self.multi.set_gain_all_rx(options.gain)
+        result,r1,r2,r3,r4 = self.multi.tune_all_rx(options.freq)
+
+This will only work reliably when you have all the same daughterboards.
+Otherwise set all freqs and gains individually.
+
+You must call self.multi.sync() at least once AFTER the flowgraph has started running.
+(This will synchronise the streams of the two usrps)
+
+This work was funded by Toby Oliver at Sensus Analytics / Path Intelligence.
+Many Thanks for making this possible.
+
+It was written by Martin Dudok van Heel at Olifantasia.
+
+
+
+Here follows a brief of the new blocks and (changes)functionality written for multi-usrp support.
+
+You can also look at the generated documentation in  
+/usr/local/share/doc/gnuradio-core-X.X
+/usr/local/share/doc/usrp-X.X
+(Make sure to build and install the documentation, go to the doc directory of the sourcetree and issue make doc; make install)
+ 
+
+gnuradio-examples:
+new/changed files:
+multi_usrp/multi_usrp_oscope.py
+multi_usrp/multi_usrp_rx_cfile.py
+
+
+gnuradio-core:
+gr.align_on_samplenumbers_ss (int nchan,int align_interval) 
+
+align several complex short (interleaved short) input channels with corresponding unsigned 32 bit sample_counters (provided as interleaved 16 bit values)
+
+Parameters:
+    	nchan 	number of complex_short input channels (including the 32 bit counting channel)
+    	align_interval 	interval at which the samples are aligned, ignored for now.
+
+Pay attention on how you connect this block It expects a minimum of 2 usrp_source_s with nchan number of channels and as mode  usrp_prims.bmFR_MODE_RX_COUNTING_32BIT enabled. This means that the first complex_short channel is an interleaved 32 bit counter. The samples are aligned by dropping samples untill the samplenumbers match.
+
+files:
+gnuradio-core/src/lib/general/gr_align_on_samplenumbers_ss.cc
+gnuradio-core/src/lib/general/gr_align_on_samplenumbers_ss.h
+gnuradio-core/src/lib/general/gr_align_on_samplenumbers_ss.i
+
+
+gr-usrp
+   added _write_fpga_reg_masked
+   added usrp_multi.py
+  new usrp_multi block which can instantiate two linked usrps as master and slave and alignes their output.
+  It has a sync() function which should be called AFTER the flowgraph has started running.
+  bool sync();
+     \brief Call this on a master usrp to sync master and slave by outputing a sync pulse on rx_a_io[15].
+        The 32 bit samplecounter of master and slave will be reset to zero and all phase and buffer related things in the usrps are reset.
+        Call this only after the flowgraph has been started, otherwise there will be no effect since everything is kept in reset state as long as the flowgraph is not running.
+     \returns true if successfull.
+
+files:
+configure.ac
+src/Makefile.am
+src/usrp1.i
+src/usrp1_source_base.cc
+src/usrp1_source_base.h
+src/usrp_multi.py
+
+usrp-0.11cvsmulti:
+usrp:
+   new constant bmFR_MODE_RX_COUNTING_32BIT    (could also be added as extra mode like FPGA_MODE_COUNTING_32BIT)
+   Use this for the mode parameter when creating a usrp when you want to use the master/slave setup or if you want to use the 32 bit counter for other things, like testing with gr.check_counting_s(True)
+
+  added register FR_RX_MASTER_SLAVE
+  added bitno and bitmaskes:
+   bmFR_MODE_RX_COUNTING_32BIT
+
+   bitnoFR_RX_SYNC 
+   bitnoFR_RX_SYNC_MASTER
+   bitnoFR_RX_SYNC_SLAVE
+
+   bitnoFR_RX_SYNC_INPUT_IOPIN 15
+   bmFR_RX_SYNC_INPUT_IOPIN  (1<<bitnoFR_RX_SYNC_INPUT_IOPIN)
+   bitnoFR_RX_SYNC_OUTPUT_IOPIN 15
+   bmFR_RX_SYNC_OUTPUT_IOPIN (1<<bitnoFR_RX_SYNC_OUTPUT_IOPIN)
+ 
+   added _write_fpga_reg_masked()
+   added new toplevel folder usrp_multi
+   added usrp_multi.v and master_control_multi.v
+   added new MULTI_ON and COUNTER_32BIT_ON defines
+      If these are turned off usrp_multi.v will behave exactly as usrp_std.v
+
+   added setting_reg_masked.v
+   changed reset behaviour of phase_acc.v and rx_buffer.v
+
+   changed generate_regs.py to handle bm and bitno defines
+
+
+files:
+firmware/include/fpga_regs_standard.v
+firmware/include/fpga_regs_common.h
+firmware/include/generate_regs.py
+firmware/include/fpga_regs_standard.h
+host/lib/usrp_basic.h
+host/lib/usrp_basic.cc
+host/lib/usrp_standard.h
+fpga/rbf/Makefile.am
+fpga/toplevel/usrp_std/usrp_std.v
+fpga/toplevel/usrp_multi/usrp_multi.esf
+fpga/toplevel/usrp_multi/usrp_multi.vh
+fpga/toplevel/usrp_multi/usrp_std.vh
+fpga/toplevel/usrp_multi/usrp_multi_config_2rxhb_0tx.vh
+fpga/toplevel/usrp_multi/usrp_multi_config_2rxhb_2tx.vh
+fpga/toplevel/usrp_multi/usrp_multi.v
+fpga/toplevel/usrp_multi/usrp_multi.qpf
+fpga/toplevel/usrp_multi/usrp_multi.psf
+fpga/toplevel/usrp_multi/usrp_multi_config_2rx_0tx.vh
+fpga/toplevel/usrp_multi/usrp_multi.qsf
+fpga/toplevel/usrp_multi/usrp_multi_config_4rx_0tx.vh
+fpga/toplevel/usrp_multi/usrp_multi.csf
+fpga/toplevel/usrp_multi/.cvsignore
+fpga/sdr_lib/rx_buffer.v
+fpga/sdr_lib/master_control_multi.v
+fpga/sdr_lib/phase_acc.v
+fpga/sdr_lib/setting_reg_masked.v
+
+
diff --git a/gnuradio-examples/python/multi_usrp/multi_usrp_oscope.py b/gnuradio-examples/python/multi_usrp/multi_usrp_oscope.py
new file mode 100755
index 000000000..d64cd1e64
--- /dev/null
+++ b/gnuradio-examples/python/multi_usrp/multi_usrp_oscope.py
@@ -0,0 +1,343 @@
+#!/usr/bin/env python
+#
+# Copyright 2004,2005,2006 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+# 
+
+# print "Loading revised usrp_oscope with additional options for scopesink..."
+
+from gnuradio import gr, gru
+from gnuradio import usrp
+from gnuradio import eng_notation
+from gnuradio.eng_option import eng_option
+from gnuradio.wxgui import stdgui, fftsink, waterfallsink, scopesink, form, slider
+from optparse import OptionParser
+import wx
+import sys
+
+import time
+from gnuradio import usrp_multi
+
+
+def pick_subdevice(u):
+    """
+    The user didn't specify a subdevice on the command line.
+    If there's a daughterboard on A, select A.
+    If there's a daughterboard on B, select B.
+    Otherwise, select A.
+    """
+    if u.db[0][0].dbid() >= 0:       # dbid is < 0 if there's no d'board or a problem
+        return (0, 0)
+    if u.db[1][0].dbid() >= 0:
+        return (1, 0)
+    return (0, 0)
+
+
+class app_flow_graph(stdgui.gui_flow_graph):
+    def __init__(self, frame, panel, vbox, argv):
+        stdgui.gui_flow_graph.__init__(self)
+
+        self.frame = frame
+        self.panel = panel
+        
+        parser = OptionParser(option_class=eng_option)
+        parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
+                          help="select USRP Rx side A or B (default=first one with a daughterboard)")
+        parser.add_option("-d", "--decim", type="int", default=128,
+                          help="set fgpa decimation rate to DECIM [default=%default]")
+        parser.add_option("-f", "--freq", type="eng_float", default=None,
+                          help="set frequency to FREQ", metavar="FREQ")
+        parser.add_option("-g", "--gain", type="eng_float", default=None,
+                          help="set gain in dB (default is midpoint)")
+        #align interval is default not yet enabled in gr.align_on_samplenumbers_ss
+        #parser.add_option("-a", "--align_interval", type="int", default=-1,
+        #                  help="Align master and slave every so much samples.")
+
+        # width 8 does not work yet with multi_usrp because it interferes with the 32 bit samplecounter
+        #parser.add_option("-8", "--width-8", action="store_true", default=False,
+        #                  help="Enable 8-bit samples across USB")
+        parser.add_option("-m", "--mux", type="intx", default=None,
+                          help="set fpga FR_RX_MUX register to MUX")
+        parser.add_option("-n", "--frame-decim", type="int", default=1,
+                          help="set oscope frame decimation factor to n [default=1]")
+        parser.add_option("-N", "--nchan", type="int", default=2,
+                          help="set nchannels to NCHAN")
+        parser.add_option("-q", "--show-q", action="store_true", default=False,
+                          help="show the q value of the complex samples")
+        parser.add_option("-s", "--show-counters", action="store_true", default=False,
+                          help="show the counters")
+        parser.add_option("-v", "--v-scale", type="eng_float", default=1000,
+                          help="set oscope initial V/div to SCALE [default=%default]")
+        parser.add_option("-t", "--t-scale", type="eng_float", default=49e-6,
+                          help="set oscope initial s/div to SCALE [default=50us]")
+        parser.add_option("-x", "--master-serialno", type="string", default=None, 
+                          help="Serial_no of the usrp which should be the MASTER (default= select any)")
+        (options, args) = parser.parse_args()
+        if len(args) != 0:
+            parser.print_help()
+            sys.exit(1)
+
+        self.show_debug_info = True
+        
+        # build the graph
+
+        #self.u = usrp.source_c(which=options.which_usrp,decim_rate=options.decim)
+        if (options.mux is None) | (4==options.nchan):
+           init_mux=None #use default mux which is 0x10321032
+        else:
+           init_mux=options.mux
+
+        init_gain=0.0
+        init_freq=0.0
+        init_align_interval=-1
+
+        self.multi=usrp_multi.multi_source_align( self,   options.master_serialno, options.decim,
+                                                 options.nchan, init_gain, init_freq, init_mux, init_align_interval)
+        self.um=self.multi.get_master_usrp()
+        self.us=self.multi.get_slave_usrp()
+
+        if options.rx_subdev_spec is None:
+            options.rx_subdev_spec = pick_subdevice(self.um)
+        if (options.mux==None) and (options.nchan!=4):
+          mux=usrp.determine_rx_mux_value(self.um, options.rx_subdev_spec)
+          mux= (mux<<8 & 0xffffffff) | (mux & 0xff)
+          self.um.set_mux(mux)
+          self.us.set_mux(mux)
+
+        # width 8 does not work yet with multi_usrp because it interferes with the 32 bit samplecounter
+        #if options.width_8:
+        #    width = 8
+        #    shift = 8
+        #    format = self.um.make_format(width, shift)
+        #    r = self.um.set_format(format)
+        #    r = self.us.set_format(format)
+            
+        # determine the daughterboard subdevice of the first channel we're using
+        self.subdevm = usrp.selected_subdev(self.um, options.rx_subdev_spec)
+        self.subdevs = usrp.selected_subdev(self.us, options.rx_subdev_spec)
+
+        input_rate = self.um.adc_freq() / self.um.decim_rate()
+
+        self.scope = scopesink.scope_sink_f(self, panel, sample_rate=input_rate,
+                                            frame_decim=options.frame_decim,
+                                            v_scale=options.v_scale,
+                                            t_scale=options.t_scale)
+        self.sink_count=0
+        self.add_to_scope((self.multi.get_master_source_c(),1),options.show_q)
+        self.add_to_scope((self.multi.get_slave_source_c(),1),options.show_q)
+        if 4==options.nchan:
+          self.add_to_scope((self.multi.get_master_source_c(),2),options.show_q)
+          self.add_to_scope((self.multi.get_slave_source_c(),2),options.show_q)
+
+        if options.show_counters:
+          self.add_to_scope((self.multi.get_master_source_c(),0),options.show_q)
+          self.add_to_scope((self.multi.get_slave_source_c(),0),options.show_q)
+
+        self._build_gui(vbox)
+
+        # set initial values
+
+        if options.gain is None:
+            # if no gain was specified, use the mid-point in dB
+            g = self.subdevm.gain_range()
+            options.gain = float(g[0]+g[1])/2
+
+        if options.freq is None:
+            # if no freq was specified, use the mid-point
+            r = self.subdevm.freq_range()
+            options.freq = float(r[0]+r[1])/2
+
+        self.set_gain(options.gain)
+
+        if self.show_debug_info:
+            self.myform['decim'].set_value(self.um.decim_rate())
+            self.myform['fs@usb'].set_value(self.um.adc_freq() / self.um.decim_rate())
+            self.myform['dbname'].set_value(self.subdevm.name())
+            self.myform['baseband'].set_value(0)
+            self.myform['ddc'].set_value(0)
+                        
+        if not(self.set_freq(options.freq)):
+            self._set_status_msg("Failed to set initial frequency")
+
+        self.multi.print_db_info()
+        self.unsynced=True
+        frame.Bind(wx.EVT_IDLE, self.onIdle)
+
+    def add_to_scope(self,source_c,show_q):
+        c2f= gr.complex_to_float ()
+        self.connect(source_c, c2f)
+        self.connect((c2f,0), (self.scope,self.sink_count))
+        self.sink_count=self.sink_count+1
+        if show_q:
+          self.connect((c2f,1), (self.scope,self.sink_count))
+          self.sink_count=self.sink_count+1
+        
+        
+    def _set_status_msg(self, msg):
+        self.frame.GetStatusBar().SetStatusText(msg, 0)
+
+    def _build_gui(self, vbox):
+
+        def _form_set_freq(kv):
+            return self.set_freq(kv['freq'])
+            
+        vbox.Add(self.scope.win, 10, wx.EXPAND)
+        
+        # add control area at the bottom
+        self.myform = myform = form.form()
+        hbox = wx.BoxSizer(wx.HORIZONTAL)
+        hbox.Add((5,0), 0, 0)
+        myform['freq'] = form.float_field(
+            parent=self.panel, sizer=hbox, label="Center freq", weight=1,
+            callback=myform.check_input_and_call(_form_set_freq, self._set_status_msg))
+
+        hbox.Add((5,0), 0, 0)
+        g = self.subdevm.gain_range()
+        myform['gain'] = form.slider_field(parent=self.panel, sizer=hbox, label="Gain",
+                                           weight=3,
+                                           min=int(g[0]), max=int(g[1]),
+                                           callback=self.set_gain)
+
+        hbox.Add((5,0), 0, 0)
+        buttonSync = form.button_with_callback(parent=self.panel, label='sync',callback=self.sync_usrps)
+        hbox.Add(buttonSync,0,wx.EXPAND)
+
+        hbox.Add((5,0), 0, 0)
+        vbox.Add(hbox, 0, wx.EXPAND)
+
+        self._build_subpanel(vbox)
+
+    def _build_subpanel(self, vbox_arg):
+        # build a secondary information panel (sometimes hidden)
+
+        # FIXME figure out how to have this be a subpanel that is always
+        # created, but has its visibility controlled by foo.Show(True/False)
+        
+        if not(self.show_debug_info):
+            return
+
+        panel = self.panel
+        vbox = vbox_arg
+        myform = self.myform
+
+        #panel = wx.Panel(self.panel, -1)
+        #vbox = wx.BoxSizer(wx.VERTICAL)
+
+        hbox = wx.BoxSizer(wx.HORIZONTAL)
+        hbox.Add((5,0), 0)
+        myform['decim'] = form.static_float_field(
+            parent=panel, sizer=hbox, label="Decim")
+
+        hbox.Add((5,0), 1)
+        myform['fs@usb'] = form.static_float_field(
+            parent=panel, sizer=hbox, label="Fs@USB")
+
+        hbox.Add((5,0), 1)
+        myform['dbname'] = form.static_text_field(
+            parent=panel, sizer=hbox)
+
+        hbox.Add((5,0), 1)
+        myform['baseband'] = form.static_float_field(
+            parent=panel, sizer=hbox, label="Analog BB")
+
+        hbox.Add((5,0), 1)
+        myform['ddc'] = form.static_float_field(
+            parent=panel, sizer=hbox, label="DDC")
+
+        hbox.Add((5,0), 0)
+        vbox.Add(hbox, 0, wx.EXPAND)
+
+
+    def set_freq(self, target_freq, sync=True):
+        """
+        Set the center frequency we're interested in for all channels,
+        on all rx daughterboards on MASTER and SLAVE.
+
+        @param target_freq: frequency in Hz
+        @param sync: sync the usrps after setting the freqs (this will clear any phase differences in the DDCS)
+        @rypte: bool
+
+        Tuning is a two step process.  First we ask the front-end to
+        tune as close to the desired frequency as it can.  Then we use
+        the result of that operation and our target_frequency to
+        determine the value for the digital down converter.
+        """
+        result,r1,r2,r3,r4 = self.multi.tune_all_rx(target_freq)
+        if sync:
+          self.sync_usrps() #sync master and slave and clear any DDC phase differences
+        if r1:
+            self.myform['freq'].set_value(target_freq)     # update displayed value
+            if self.show_debug_info:
+                self.myform['baseband'].set_value(r1.baseband_freq)
+                self.myform['ddc'].set_value(r1.dxc_freq)
+        return result
+
+    def set_freq_chan0(self, target_freq, sync=True):
+        """
+        Set the center frequency we're interested in for rx chan 0 only on MASTER and SLAVE.
+
+        @param target_freq: frequency in Hz
+        @param sync: sync the usrps after setting the freqs (this will clear any phase differences in the DDCS)
+        @rypte: bool
+
+        Tuning is a two step process.  First we ask the front-end to
+        tune as close to the desired frequency as it can.  Then we use
+        the result of that operation and our target_frequency to
+        determine the value for the digital down converter.
+        """
+        rm = usrp.tune(self.um, 0, self.subdevm, target_freq)
+        rs = usrp.tune(self.us, 0, self.subdevs, target_freq)
+        r=rm
+        if sync:
+          self.sync_usrps()  #sync master and slave and clear any DDC phase differences
+        if r:
+            self.myform['freq'].set_value(target_freq)     # update displayed value
+            if self.show_debug_info:
+                self.myform['baseband'].set_value(r.baseband_freq)
+                self.myform['ddc'].set_value(r.dxc_freq)
+            return True
+
+        return False
+
+    def set_gain(self, gain):
+        self.myform['gain'].set_value(gain)     # update displayed value
+        self.multi.set_gain_all_rx(gain)
+
+    def set_gain_chan0(self, gain):
+        self.myform['gain'].set_value(gain)     # update displayed value
+        self.subdevm.set_gain(gain)
+        self.subdevs.set_gain(gain)
+
+    def onIdle(self,evt):
+        if self.unsynced:
+          time.sleep(0.5)
+          self.unsynced=True
+          self.multi.sync()
+          self.unsynced=False
+          #print 'synced'
+
+    def sync_usrps(self):
+        self.multi.sync()
+
+def main ():
+    app = stdgui.stdapp(app_flow_graph, "MULTI_USRP O'scope", nstatus=1)
+    app.MainLoop()
+
+if __name__ == '__main__':
+    main ()
diff --git a/gnuradio-examples/python/multi_usrp/multi_usrp_rx_cfile.py b/gnuradio-examples/python/multi_usrp/multi_usrp_rx_cfile.py
new file mode 100755
index 000000000..6084aba3d
--- /dev/null
+++ b/gnuradio-examples/python/multi_usrp/multi_usrp_rx_cfile.py
@@ -0,0 +1,131 @@
+#!/usr/bin/env python
+
+"""
+Read samples 2 from two linked synchronised USRP's and write to file formatted as binary
+single-precision complex values.
+Make sure you read README on how to link the two usrps
+
+"""
+
+from gnuradio import gr, eng_notation
+from gnuradio import audio
+from gnuradio import usrp
+from gnuradio.eng_option import eng_option
+from optparse import OptionParser
+import sys
+
+import time
+from gnuradio import usrp_multi
+
+class my_graph(gr.flow_graph):
+
+    def __init__(self):
+        gr.flow_graph.__init__(self)
+
+        usage="%prog: [options] output_filename"
+        parser = OptionParser(option_class=eng_option, usage=usage)
+        parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=(0, 0),
+                          help="select USRP Rx side A or B (default=A)")
+        parser.add_option("-d", "--decim", type="int", default=128,
+                          help="set selfpa decimation rate to DECIM [default=%default]")
+        parser.add_option("-f", "--freq", type="eng_float", default=0.0,
+                          help="set frequency to FREQ", metavar="FREQ")
+        parser.add_option("-g", "--gain", type="eng_float", default=None,
+                          help="set gain in dB (default is midpoint)")
+        parser.add_option("-n", "--nchan", type="intx", default=2,
+                          help="set nchannels to NCHAN")
+        parser.add_option("-N", "--nsamples", type="eng_float", default=None,
+                          help="number of samples to collect [default=+inf]")
+        parser.add_option ("-o", "--output-file-m", default="usrp_rx_m.dat",
+                       help="write master data to FILE", metavar="FILE")
+        parser.add_option ("--output-file-m2", default="usrp_rx_m2.dat",
+                       help="write master data from second channel to FILE", metavar="FILE")
+        parser.add_option ("-p", "--output-file-s", default="usrp_rx_s.dat",
+                       help="write slave data to FILE", metavar="FILE")
+        parser.add_option ("--output-file-s2", default="usrp_rx_s2.dat",
+                       help="write slave data from second channel to FILE", metavar="FILE")
+        parser.add_option("-x", "--master-serialno", type="string", default=None, 
+                          help="Serial_no of the usrp which should be the MASTER (default= select any)")
+        (options, args) = parser.parse_args ()
+        if len(args) != 0:
+            parser.print_help()
+            raise SystemExit, 1
+
+        if options.freq is None:
+            parser.print_help()
+            sys.stderr.write('You must specify the frequency with -f FREQ\n');
+            raise SystemExit, 1
+
+        # build the graph
+        self.multi=usrp_multi.multi_source_align( fg=self, master_serialno=options.master_serialno, decim=options.decim, 
+                                                  nchan=options.nchan )
+        self.um=self.multi.get_master_usrp()
+        self.us=self.multi.get_slave_usrp()
+
+        dst_m=gr.file_sink (gr.sizeof_gr_complex, options.output_file_m)
+        dst_s=gr.file_sink (gr.sizeof_gr_complex, options.output_file_s)
+        if options.nsamples is None:
+            self.connect((self.multi.get_master_source_c(),1),dst_m)
+            self.connect((self.multi.get_slave_source_c(),1),dst_s)
+        else:
+            head_m = gr.head(gr.sizeof_gr_complex, int(options.nsamples))
+            head_s = gr.head(gr.sizeof_gr_complex, int(options.nsamples))
+            self.connect((self.multi.get_master_source_c(),1),head_m,dst_m)
+            self.connect((self.multi.get_slave_source_c(),1),head_s,dst_s)
+
+        if(4==options.nchan):
+            dst_m2=gr.file_sink (gr.sizeof_gr_complex, options.output_file_m2)
+            dst_s2=gr.file_sink (gr.sizeof_gr_complex, options.output_file_s2)
+            if options.nsamples is None:
+                self.connect((self.multi.get_master_source_c(),2),dst_m2)
+                self.connect((self.multi.get_slave_source_c(),2),dst_s2) 
+            else:
+                head_m2 = gr.head(gr.sizeof_gr_complex, int(options.nsamples))
+                head_s2 = gr.head(gr.sizeof_gr_complex, int(options.nsamples))
+                self.connect((self.multi.get_master_source_c(),2),head_m2,dst_m2)
+                self.connect((self.multi.get_slave_source_c(),2),head_s2,dst_s2) 
+
+        if options.rx_subdev_spec is None:
+            options.rx_subdev_spec = usrp.pick_rx_subdevice(self.um)
+
+        if (options.nchan!=4):
+          mux=usrp.determine_rx_mux_value(self.um, options.rx_subdev_spec)
+          mux= (mux<<8 & 0xffffffff) | (mux & 0xff)
+          self.um.set_mux(mux)
+          self.us.set_mux(mux)
+
+        # determine the daughterboard subdevice we're using
+        self.subdevm = usrp.selected_subdev(self.um, options.rx_subdev_spec)
+        self.subdevs = usrp.selected_subdev(self.us, options.rx_subdev_spec)
+        print "Using MASTER RX d'board %s" % (self.subdevm.side_and_name(),)
+        print "Using SLAVE RX d'board %s" % (self.subdevs.side_and_name(),)
+        input_rate = self.um.adc_freq() / self.um.decim_rate()
+        print "USB sample rate %s" % (eng_notation.num_to_str(input_rate))
+
+        if options.gain is None:
+            # if no gain was specified, use the mid-point in dB
+            g = self.subdevm.gain_range()
+            options.gain = float(g[0]+g[1])/2
+
+        self.multi.set_gain_all_rx(options.gain)
+        result,r1,r2,r3,r4 = self.multi.tune_all_rx(options.freq)
+        if not result:
+            sys.stderr.write('Failed to set frequency\n')
+            raise SystemExit, 1
+
+    def sync_usrps(self):
+        self.multi.sync()   
+       
+        
+if __name__ == '__main__':
+    fg=my_graph()
+    fg.start()
+    #time.sleep(0.5)
+    fg.sync_usrps() 
+    raw_input ('Press Enter to quit: ')
+    fg.stop()
+    #try:
+    #    fg.start()
+    #    fg.sync_usrps()
+    #except KeyboardInterrupt:
+    #    pass