add the script

.gitignore

@@ -51,4 +51,6 @@ Module.symvers
 Mkfile.old
 dkms.conf
 
-build/
+build/
+*.pyc
+__pycache__/

src/waveforms.c

@@ -1,7 +1,9 @@
 
-/* This file was automatically generated by "generate_waveforms.py".
+/* This file was automatically generated by "gen_wave.py".
    (C) 2014 Christophe Jacquet.
+   Modified by kuba201
    Released under the GNU GPL v3 license.
 */
 
 float waveform_biphase[24] = {0.002532628775852384, -6.480266785053461e-18, -0.004522551385450683, 2.807603181808536e-17, 0.00940690688173742, -2.1836329850641248e-17, -0.025868993924777907, -1.1701083086090883e-17, 0.1552139635486674, 0.4, 0.5432488724203361, 0.4, 0.0, -0.4, -0.5432488724203361, -0.4, -0.1552139635486674, 1.1701083086090883e-17, 0.025868993924777907, 2.1836329850641248e-17, -0.00940690688173742, -2.807603181808536e-17, 0.004522551385450683, 6.480266785053461e-18};
+

src/waveforms.h

@@ -1,7 +1,8 @@
 
-/* This file was automatically generated by "generate_waveforms.py".
+/* This file was automatically generated by "gen_wave.py".
    (C) 2014 Christophe Jacquet.
+   Modified by kuba201
    Released under the GNU GPL v3 license.
- */
+*/
 
 extern float waveform_biphase[24];

waveform/Pydemod/README.md

@@ -0,0 +1,11 @@
+Pydemod
+-------
+
+Pydemod is a set of Python libraries and tools for demodulating radio signals. It does not intend to compete with full-featured packages such as GNU Radio. Instead, it strives to allow radio enthusiasts to gain hands-on experience with modulation schemes.
+
+Pydemod relies on [NumPy](http://numpy.scipy.org/)/[SciPy](http://www.scipy.org/).
+
+Pydemod is licensed under the terms of the [GNU GPL v3](https://www.gnu.org/copyleft/gpl.html).
+
+----
+_Pydemod is developed by [Christophe Jacquet](http://www.jacquet80.eu/), [F8FTK](http://f8ftk.tk)._

waveform/Pydemod/src/gen_wave.py

@@ -0,0 +1,80 @@
+#!/usr/bin/python
+
+
+#   PiFmRds - FM/RDS transmitter for the Raspberry Pi
+#   Copyright (C) 2014 Christophe Jacquet, F8FTK
+#
+#   See https://github.com/ChristopheJacquet/PiFmRds
+#
+#   This program 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 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#   This program generates the waveform of a single biphase symbol
+#
+#   This program uses Pydemod, see https://github.com/ChristopheJacquet/Pydemod
+
+import pydemod.app.rds as rds
+import numpy
+import io
+import matplotlib.pyplot as plt
+
+sample_rate = 9500
+
+outc = io.open("waveforms.c", mode="w", encoding="utf8")
+outh = io.open("waveforms.h", mode="w", encoding="utf8")
+
+header = u"""
+/* This file was automatically generated by "gen_wave.py".
+   (C) 2014 Christophe Jacquet.
+   Modified by kuba201
+   Released under the GNU GPL v3 license.
+*/
+
+"""
+
+outc.write(header)
+outh.write(header)
+
+def generate_bit(name):
+    offset = int(sample_rate*0.004) # 190 khz = 760
+    count = int(offset / 10**(len(str(offset)) - 1)) # 760 / 100 = 7
+    l = int(sample_rate / 1187.5) // 2 # 16/2 = 8
+
+    sample = numpy.zeros(count*l)
+    sample[l] = 1
+    sample[2*l] = -1
+
+    # Apply the data-shaping filter
+    sf = rds.pulse_shaping_filter(l*16, sample_rate-1)
+    shapedSamples = numpy.convolve(sample, sf)
+
+    out = shapedSamples[offset-l*count:offset+l*count] #[offset:offset+l*count]
+    #plt.plot(sf)
+    #plt.plot(shapedSamples)
+    plt.plot(out)
+    plt.show()
+
+    outc.write(u"float waveform_{name}[{size}] = {{{values}}};\n\n".format(
+        name = name,
+        values = u", ".join(map(str, out / 2.5)),
+        size = len(out)))
+        # note: need to limit the amplitude so as not to saturate when the biphase
+        # waveforms are summed
+
+    outh.write(u"extern float waveform_{name}[{size}];\n".format(name=name, size=len(out)))
+
+
+generate_bit("biphase")
+
+outc.close()
+outh.close()

waveform/Pydemod/src/pydemod/app/rds.py

@@ -0,0 +1,11 @@
+# This file is part of Pydemod
+# Copyright Christophe Jacquet (F8FTK), 2014
+# Licence: GNU GPL v3
+# See: https://github.com/ChristopheJacquet/Pydemod
+
+import numpy
+
+import pydemod.filters.shaping as shaping
+
+def pulse_shaping_filter(length, sample_rate):
+    return shaping.rrcosfilter(length, 1, 1/(2*1187.5), sample_rate+1) [1]

waveform/Pydemod/src/pydemod/filters/shaping.py

@@ -0,0 +1,64 @@
+# This file is part of Pydemod
+# Copyright Christophe Jacquet (F8FTK), 2014
+# Licence: GNU GPL v3
+# See: https://github.com/ChristopheJacquet/Pydemod
+#
+# Contains code from CommPy, used under the terms of the GPL 
+# https://github.com/veeresht/CommPy/blob/master/commpy/filters.py
+# (c) 2012 Veeresh Taranalli
+
+import numpy
+
+# The following function is from:
+# https://github.com/veeresht/CommPy/blob/master/commpy/filters.py
+# See also: https://en.wikipedia.org/wiki/Root-raised-cosine_filter
+def rrcosfilter(N, alpha, Ts, Fs):
+    """
+    Generates a root raised cosine (RRC) filter (FIR) impulse response.
+    
+    Parameters
+    ----------
+    N : int 
+        Length of the filter in samples.
+    
+    alpha: float
+        Roll off factor (Valid values are [0, 1]).
+    
+    Ts : float
+        Symbol period in seconds.
+    
+    Fs : float 
+        Sampling Rate in Hz.
+    
+    Returns
+    ---------
+
+    h_rrc : 1-D ndarray of floats
+        Impulse response of the root raised cosine filter.
+    
+    time_idx : 1-D ndarray of floats 
+        Array containing the time indices, in seconds, for 
+        the impulse response.
+    """
+
+    T_delta = 1/float(Fs)
+    time_idx = ((numpy.arange(N)-N/2))*T_delta
+    sample_num = numpy.arange(N)
+    h_rrc = numpy.zeros(N, dtype=float)
+        
+    for x in sample_num:
+        t = (x-N/2)*T_delta
+        if t == 0.0:
+            h_rrc[x] = 1.0 - alpha + (4*alpha/numpy.pi)
+        elif alpha != 0 and t == Ts/(4*alpha):
+            h_rrc[x] = (alpha/numpy.sqrt(2))*(((1+2/numpy.pi)* \
+                    (numpy.sin(numpy.pi/(4*alpha)))) + ((1-2/numpy.pi)*(numpy.cos(numpy.pi/(4*alpha)))))
+        elif alpha != 0 and t == -Ts/(4*alpha):
+            h_rrc[x] = (alpha/numpy.sqrt(2))*(((1+2/numpy.pi)* \
+                    (numpy.sin(numpy.pi/(4*alpha)))) + ((1-2/numpy.pi)*(numpy.cos(numpy.pi/(4*alpha)))))
+        else:
+            h_rrc[x] = (numpy.sin(numpy.pi*t*(1-alpha)/Ts) +  \
+                    4*alpha*(t/Ts)*numpy.cos(numpy.pi*t*(1+alpha)/Ts))/ \
+                    (numpy.pi*t*(1-(4*alpha*t/Ts)*(4*alpha*t/Ts))/Ts)
+        
+    return time_idx, h_rrc

waveform/Pydemod/src/waveforms.c

@@ -0,0 +1,8 @@
+
+/* This file was automatically generated by "generate_waveforms.py".
+   (C) 2014 Christophe Jacquet.
+   Released under the GNU GPL v3 license.
+*/
+
+float waveform_biphase[24] = {0.002532628775852384, -6.480266785053461e-18, -0.004522551385450683, 2.807603181808536e-17, 0.00940690688173742, -2.1836329850641248e-17, -0.025868993924777907, -1.1701083086090883e-17, 0.1552139635486674, 0.4, 0.5432488724203361, 0.4, 0.0, -0.4, -0.5432488724203361, -0.4, -0.1552139635486674, 1.1701083086090883e-17, 0.025868993924777907, 2.1836329850641248e-17, -0.00940690688173742, -2.807603181808536e-17, 0.004522551385450683, 6.480266785053461e-18};
+

waveform/Pydemod/src/waveforms.h

@@ -0,0 +1,7 @@
+
+/* This file was automatically generated by "generate_waveforms.py".
+   (C) 2014 Christophe Jacquet.
+   Released under the GNU GPL v3 license.
+*/
+
+extern float waveform_biphase[24];