Simple FM transmitter using gnuradio - Revision history

Coinchon at 18:03, 2 January 2010

2010-01-02T18:03:01Z

Coinchon: /* Pys FM_tx_FIFO(grc_wxgui.top_block_gui):thon code */

2010-01-02T18:01:46Z

Pys FM_tx_FIFO(grc_wxgui.top_block_gui):thon code

Coinchon at 18:00, 2 January 2010

2010-01-02T18:00:01Z

Coinchon at 17:56, 2 January 2010

2010-01-02T17:56:19Z

Coinchon at 17:47, 2 January 2010

2010-01-02T17:47:12Z

Coinchon: New page: Simple FM transmitter using gnuradio. Tools needed: gnuradio 3.2 grc (gnuradio companion) *USRP

2010-01-02T17:45:15Z

New page: Simple FM transmitter using gnuradio. Tools needed: *gnuradio 3.2 *grc (gnuradio companion) *USRP

New page

Simple FM transmitter using gnuradio.

Tools needed:
*gnuradio 3.2
*grc (gnuradio companion)
*USRP

@@ Line 9: / Line 9: @@
 Mono FM transmission is very simple as all necessary blocks already exist in gnuradio.
 In this example we will show how to make a FM transmission from an mp3 stream for an Internet radio.
-==GRC Schema==
+Input file is a unix FIFO file that means that we need to feed it externally from the shell using these commands:
 Creation of the FIFO file (once):
@@ Line 124: / Line 122: @@
   	tb = FM_tx_FIFO()
   	tb.Run(True)

@@ Line 48: / Line 48: @@
   	def __init__(self):
   		grc_wxgui.top_block_gui.__init__(self, title="Simple FM Transmitter FIFO input")
-−
-		##################################################
+ 		##################################################
-		# Variables
+ 		# Variables
-		##################################################
+ 		##################################################
-		self.samp_rate = samp_rate = 32000
+ 		self.samp_rate = samp_rate = 32000
-		self.FM_freq = FM_freq = 107900000
+ 		self.FM_freq = FM_freq = 107900000
-−
-		##################################################
+ 		##################################################
-		# Controls
+ 		# Controls
-		##################################################
+ 		##################################################
-		_FM_freq_sizer = wx.BoxSizer(wx.VERTICAL)
+ 		_FM_freq_sizer = wx.BoxSizer(wx.VERTICAL)
-		self._FM_freq_text_box = forms.text_box(
+ 		self._FM_freq_text_box = forms.text_box(
-			parent=self.GetWin(),
+ 			parent=self.GetWin(),
-			sizer=_FM_freq_sizer,
+ 			sizer=_FM_freq_sizer,
-			value=self.FM_freq,
+ 			value=self.FM_freq,
-			callback=self.set_FM_freq,
+ 			callback=self.set_FM_freq,
-			label="FM Frequency",
+ 			label="FM Frequency",
-			converter=forms.float_converter(),
+ 			converter=forms.float_converter(),
-			proportion=0,
+ 			proportion=0,
-−
+ 		)
-		self._FM_freq_slider = forms.slider(
+ 		self._FM_freq_slider = forms.slider(
-			parent=self.GetWin(),
+ 			parent=self.GetWin(),
-			sizer=_FM_freq_sizer,
+ 			sizer=_FM_freq_sizer,
-			value=self.FM_freq,
+ 			value=self.FM_freq,
-			callback=self.set_FM_freq,
+ 			callback=self.set_FM_freq,
-			minimum=87500000,
+ 			minimum=87500000,
-			maximum=108000000,
+ 			maximum=108000000,
-			num_steps=205,
+ 			num_steps=205,
-			style=wx.SL_HORIZONTAL,
+ 			style=wx.SL_HORIZONTAL,
-			cast=float,
+ 			cast=float,
-			proportion=1,
+ 			proportion=1,
-−
+ 		)
-		self.Add(_FM_freq_sizer)
+ 		self.Add(_FM_freq_sizer)
-−
-		##################################################
+ 		##################################################
-		# Blocks
+ 		# Blocks
-		##################################################
+ 		##################################################
-		self.blks2_wfm_tx_0 = blks2.wfm_tx(
+ 		self.blks2_wfm_tx_0 = blks2.wfm_tx(
-			audio_rate=samp_rate,
+ 			audio_rate=samp_rate,
-			quad_rate=640000,
+ 			quad_rate=640000,
-			tau=75e-6,
+ 			tau=75e-6,
-			max_dev=75e3,
+ 			max_dev=75e3,
-−
+ 		)
-		self.gr_file_source_0 = gr.file_source(gr.sizeof_short*1, "/home/mc/FM_demo/stream_32k.fifo", True)
+ 		self.gr_file_source_0 = gr.file_source(gr.sizeof_short*1, "/home/mc/FM_demo/stream_32k.fifo", True)
-		self.gr_multiply_const_vxx_0 = gr.multiply_const_vcc((32768, ))
+ 		self.gr_multiply_const_vxx_0 = gr.multiply_const_vcc((32768, ))
-		self.gr_multiply_const_vxx_1 = gr.multiply_const_vff((0.00003, ))
+ 		self.gr_multiply_const_vxx_1 = gr.multiply_const_vff((0.00003, ))
-		self.gr_short_to_float_1 = gr.short_to_float()
+ 		self.gr_short_to_float_1 = gr.short_to_float()
-		self.usrp_simple_sink_x_0 = grc_usrp.simple_sink_c(which=0, side="B")
+ 		self.usrp_simple_sink_x_0 = grc_usrp.simple_sink_c(which=0, side="B")
-		self.usrp_simple_sink_x_0.set_interp_rate(200)
+ 		self.usrp_simple_sink_x_0.set_interp_rate(200)
-		self.usrp_simple_sink_x_0.set_frequency(FM_freq, verbose=True)
+ 		self.usrp_simple_sink_x_0.set_frequency(FM_freq, verbose=True)
-		self.usrp_simple_sink_x_0.set_gain(0)
+ 		self.usrp_simple_sink_x_0.set_gain(0)
-		self.usrp_simple_sink_x_0.set_enable(True)
+ 		self.usrp_simple_sink_x_0.set_enable(True)
-−
-		##################################################
+ 		##################################################
-		# Connections
+ 		# Connections
-		##################################################
+ 		##################################################
-		self.connect((self.gr_multiply_const_vxx_0, 0), (self.usrp_simple_sink_x_0, 0))
+ 		self.connect((self.gr_multiply_const_vxx_0, 0), (self.usrp_simple_sink_x_0, 0))
-		self.connect((self.gr_short_to_float_1, 0), (self.gr_multiply_const_vxx_1, 0))
+ 		self.connect((self.gr_short_to_float_1, 0), (self.gr_multiply_const_vxx_1, 0))
-		self.connect((self.gr_file_source_0, 0), (self.gr_short_to_float_1, 0))
+ 		self.connect((self.gr_file_source_0, 0), (self.gr_short_to_float_1, 0))
-		self.connect((self.gr_multiply_const_vxx_1, 0), (self.blks2_wfm_tx_0, 0))
+ 		self.connect((self.gr_multiply_const_vxx_1, 0), (self.blks2_wfm_tx_0, 0))
-		self.connect((self.blks2_wfm_tx_0, 0), (self.gr_multiply_const_vxx_0, 0))
+ 		self.connect((self.blks2_wfm_tx_0, 0), (self.gr_multiply_const_vxx_0, 0))
-−
-	def set_samp_rate(self, samp_rate):
+ 	def set_samp_rate(self, samp_rate):
-		self.samp_rate = samp_rate
+ 		self.samp_rate = samp_rate
-−
-	def set_FM_freq(self, FM_freq):
+ 	def set_FM_freq(self, FM_freq):
-		self.FM_freq = FM_freq
+ 		self.FM_freq = FM_freq
-		self._FM_freq_slider.set_value(self.FM_freq)
+ 		self._FM_freq_slider.set_value(self.FM_freq)
-		self._FM_freq_text_box.set_value(self.FM_freq)
+ 		self._FM_freq_text_box.set_value(self.FM_freq)
-		self.usrp_simple_sink_x_0.set_frequency(self.FM_freq)
+ 		self.usrp_simple_sink_x_0.set_frequency(self.FM_freq)
-−
   if __name__ == '__main__':
-	parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
+ 	parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
-	(options, args) = parser.parse_args()
+ 	(options, args) = parser.parse_args()
-	tb = FM_tx_FIFO()
+ 	tb = FM_tx_FIFO()
-	tb.Run(True)
+ 	tb.Run(True)

← Older revision		Revision as of 18:00, 2 January 2010
Line 22:		Line 22:

	Option "-m" is to convert stream to mono, "-r32000" perform sample rate conversion to 32kHz.		Option "-m" is to convert stream to mono, "-r32000" perform sample rate conversion to 32kHz.
		+
		+	==Python code==
		+	Code generated by GRC
		+
		+	#!/usr/bin/env python
		+	##################################################
		+	# Gnuradio Python Flow Graph
		+	# Title: Simple FM Transmitter FIFO input
		+	# Author: Mathias Coinchon
		+	# Description: Simple FM Transmitter using FIFO
		+	# Generated: Sat Jan 2 18:56:38 2010
		+	##################################################
		+
		+	from gnuradio import blks2
		+	from gnuradio import gr
		+	from gnuradio.eng_option import eng_option
		+	from gnuradio.wxgui import forms
		+	from grc_gnuradio import usrp as grc_usrp
		+	from grc_gnuradio import wxgui as grc_wxgui
		+	from optparse import OptionParser
		+	import wx
		+
		+	class FM_tx_FIFO(grc_wxgui.top_block_gui):
		+
		+	def __init__(self):
		+	grc_wxgui.top_block_gui.__init__(self, title="Simple FM Transmitter FIFO input")
		+
		+	##################################################
		+	# Variables
		+	##################################################
		+	self.samp_rate = samp_rate = 32000
		+	self.FM_freq = FM_freq = 107900000
		+
		+	##################################################
		+	# Controls
		+	##################################################
		+	_FM_freq_sizer = wx.BoxSizer(wx.VERTICAL)
		+	self._FM_freq_text_box = forms.text_box(
		+	parent=self.GetWin(),
		+	sizer=_FM_freq_sizer,
		+	value=self.FM_freq,
		+	callback=self.set_FM_freq,
		+	label="FM Frequency",
		+	converter=forms.float_converter(),
		+	proportion=0,
		+	)
		+	self._FM_freq_slider = forms.slider(
		+	parent=self.GetWin(),
		+	sizer=_FM_freq_sizer,
		+	value=self.FM_freq,
		+	callback=self.set_FM_freq,
		+	minimum=87500000,
		+	maximum=108000000,
		+	num_steps=205,
		+	style=wx.SL_HORIZONTAL,
		+	cast=float,
		+	proportion=1,
		+	)
		+	self.Add(_FM_freq_sizer)
		+
		+	##################################################
		+	# Blocks
		+	##################################################
		+	self.blks2_wfm_tx_0 = blks2.wfm_tx(
		+	audio_rate=samp_rate,
		+	quad_rate=640000,
		+	tau=75e-6,
		+	max_dev=75e3,
		+	)
		+	self.gr_file_source_0 = gr.file_source(gr.sizeof_short*1, "/home/mc/FM_demo/stream_32k.fifo", True)
		+	self.gr_multiply_const_vxx_0 = gr.multiply_const_vcc((32768, ))
		+	self.gr_multiply_const_vxx_1 = gr.multiply_const_vff((0.00003, ))
		+	self.gr_short_to_float_1 = gr.short_to_float()
		+	self.usrp_simple_sink_x_0 = grc_usrp.simple_sink_c(which=0, side="B")
		+	self.usrp_simple_sink_x_0.set_interp_rate(200)
		+	self.usrp_simple_sink_x_0.set_frequency(FM_freq, verbose=True)
		+	self.usrp_simple_sink_x_0.set_gain(0)
		+	self.usrp_simple_sink_x_0.set_enable(True)
		+
		+	##################################################
		+	# Connections
		+	##################################################
		+	self.connect((self.gr_multiply_const_vxx_0, 0), (self.usrp_simple_sink_x_0, 0))
		+	self.connect((self.gr_short_to_float_1, 0), (self.gr_multiply_const_vxx_1, 0))
		+	self.connect((self.gr_file_source_0, 0), (self.gr_short_to_float_1, 0))
		+	self.connect((self.gr_multiply_const_vxx_1, 0), (self.blks2_wfm_tx_0, 0))
		+	self.connect((self.blks2_wfm_tx_0, 0), (self.gr_multiply_const_vxx_0, 0))
		+
		+	def set_samp_rate(self, samp_rate):
		+	self.samp_rate = samp_rate
		+
		+	def set_FM_freq(self, FM_freq):
		+	self.FM_freq = FM_freq
		+	self._FM_freq_slider.set_value(self.FM_freq)
		+	self._FM_freq_text_box.set_value(self.FM_freq)
		+	self.usrp_simple_sink_x_0.set_frequency(self.FM_freq)
		+
		+	if __name__ == '__main__':
		+	parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
		+	(options, args) = parser.parse_args()
		+	tb = FM_tx_FIFO()
		+	tb.Run(True)

@@ Line 4: / Line 4: @@
 *gnuradio 3.2
 *grc (gnuradio companion)
 *USRP
-GRC Schema:
+Mono FM transmission is very simple as all necessary blocks already exist in gnuradio.
 [[Image:FM transmitter FIFO.png]]

@@ Line 1: / Line 1: @@
 Simple FM transmitter using gnuradio.
@@ Line 6: / Line 5: @@
 *grc (gnuradio companion)
 *USRP