Salut Habr.
Dans un article précédent sur la radio définie par logiciel, on m'a demandé comment décoder RDS en utilisant GNU Radio. Le décodeur RDS n'est pas si facile à créer à partir de zéro, mais heureusement pour nous, il est déjà intégré à GNU Radio, il est donc facile de voir comment cela fonctionne sans écrire une seule ligne de code, juste le récepteur RTL-SDR.
Comment cela fonctionne, a continué sous la coupe.
Je ne reviendrai pas sur GNU Radio et son installation, elle a déjà été décrite
précédemment . En bref, une distribution pour Windows peut être trouvée
ici . Passons à RDS.
Si quelqu'un n'est soudain pas au courant, le
RDS (Radio Data System) est un protocole utilisé en radiodiffusion FM conventionnelle pour transmettre des informations numériques supplémentaires (heure, taux de change, météo, etc.). La transmission s'effectue à une vitesse de 1187,5 bps à une fréquence de 57 KHz (3e harmonique de la tonalité pilote), une minimisation de phase utilisant un codage de phase BPSK (Key Bift Phase Shift Keying) est utilisée. Le RDS au niveau des bits a déjà été pris en compte sur le hub
avant , eh bien, nous allons passer à GNU Radio.
Le décodeur pour GNU Radio a été créé il y a environ
10 ans , mais il est inutile de regarder cette version, les noms de nombreux blocs ont changé et les exemples qui y sont donnés ne fonctionnent plus. La fourche mise à jour peut être prise à
partir d'ici .
Soit dit en passant, cela n'a pas fonctionné pour collecter gr-rds à partir de la source pour Windows - cmake donne des erreurs pour l'absence de Boost, bien qu'il soit installé. Il est incompréhensible, au fait, qu'au cours des années d'existence cmake et boost, cmake n'a pas appris à trouver des chemins dans Windows - comme trouver un dossier sur un disque n'est pas du tout sorcier (si quelqu'un connaît la solution, écrivez dans les commentaires, bien qu'à en juger par Stack Overflow, le problème
existe depuis des années) et tous s'en moquent). Mais il s'est avéré que nous n'en avons pas besoin - le décodeur RDS a déjà été ajouté à GNU Radio, donc à partir du projet sur github, nous n'avons besoin que d'exemples qui se trouvent dans le dossier
apps .
Le schéma fonctionnel inclus dans les exemples est assez monstrueux, et en plus, des erreurs sont générées lors de son ouverture (les blocs sont marqués en rouge).
Dans la vraie vie, cependant, tout est plus simple - 2/3 du circuit est un lecteur stéréo pour FM, où les canaux L + R et LR sont extraits du signal d'origine, traités et alimentés vers la carte son. Ce n'est pas pertinent pour nous maintenant, donc ces blocs peuvent être supprimés (d'autant plus que pour une raison quelconque, cela n'a pas fonctionné, mais c'était trop paresseux pour comprendre). Des erreurs surviennent en raison du paramètre Grid Position, qui, apparemment, n'est pas pris en charge par la version Windows, mais il peut être supprimé sans problème, il n'affecte pas la fonctionnalité.
Après avoir supprimé "tout ce qui est superflu", le circuit de décodage RDS fonctionne comme suit:
Voyons ce qu'il y a.
Le signal initial provient de la source RTL-SDR, la fréquence est définie par le paramètre freq, qui est du type WX GUI Slider (oui, vous pouvez créer votre propre interface utilisateur dans GNU Radio et il y a des commandes de base). Pour éviter un pic à fréquence nulle au centre, le paramètre freq_offset est utilisé, le bloc Frequency Xlating décale la fréquence de cette valeur. Le bloc de réception WBFM, comme son nom l'indique, effectue la démodulation FM, puis la fréquence est à nouveau décalée pour mettre en évidence le RDS 57KHz lui-même. Le bloc Root Cosined Filter sélectionne une fréquence étroite, mais le décodeur MPSK avec le paramètre 2 effectue le décodage BPSK (le RDS lui-même est transmis en utilisant
une modulation de phase à deux états). Le RDS utilise
un codage différentiel , de sorte que le décodeur différentiel correspondant est appelé, et enfin, le flux binaire fini est envoyé au bloc du décodeur RDS (ses sources peuvent être consultées sur
github ). Après le décodeur, une partie tout aussi importante est l'
analyseur RDS - il y a beaucoup de types de paquets dans RDS, et l'analyseur fait tout le travail pour les déchiffrer.
En fait, c'est tout. Les résultats du décodeur sur le KDPV et les captures d'écran.
Si quelqu'un a besoin d'utiliser le programme en mode sans interface utilisateur, vous pouvez utiliser le bloc FR Tap, une description plus détaillée
ici , personnellement, je ne l'ai pas essayé. Si le RDS de niveau binaire inférieur est intéressant, je l'ai considéré
plus tôt , pour l'intérêt général, il peut également être utile.
Comme d'habitude, toutes les expériences réussies.
Le fichier GRC d'origine fonctionnant sous Windows est sous un spoiler (il suffit de changer la fréquence de la station de radio).
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<key>_coordinate</key> <value>(184, 6)</value> </param> <param> <key>_rotation</key> <value>0</value> </param> <param> <key>grid_pos</key> <value></value> </param> <param> <key>id</key> <value>nb</value> </param> <param> <key>labels</key> <value>['BB', 'Demod', 'L+R', 'Pilot', 'DSBSC', 'RDS', 'L-R', 'RDS constellation','Waterfall']</value> </param> <param> <key>notebook</key> <value></value> </param> <param> <key>style</key> <value>wx.NB_TOP</value> </param> </block> <block> <key>root_raised_cosine_filter</key> <param> <key>alpha</key> <value>1</value> </param> <param> <key>alias</key> <value></value> </param> <param> <key>comment</key> <value></value> </param> <param> <key>affinity</key> <value></value> </param> <param> <key>decim</key> <value>1</value> </param> <param> <key>_enabled</key> <value>True</value> </param> <param> <key>type</key> <value>fir_filter_ccf</value> </param> <param> <key>_coordinate</key> <value>(304, 516)</value> </param> <param> <key>_rotation</key> <value>0</value> </param> <param> <key>gain</key> <value>1</value> </param> <param> <key>id</key> <value>root_raised_cosine_filter_0</value> </param> <param> <key>interp</key> <value>1</value> </param> <param> <key>maxoutbuf</key> <value>0</value> </param> <param> <key>minoutbuf</key> <value>0</value> </param> <param> <key>ntaps</key> <value>100</value> </param> <param> <key>samp_rate</key> <value>samp_rate/bb_decim/audio_decim</value> </param> <param> <key>sym_rate</key> <value>2375</value> </param> </block> <block> <key>rtlsdr_source</key> <param> <key>alias</key> <value></value> </param> <param> <key>ant0</key> <value></value> </param> <param> <key>bb_gain0</key> <value>20</value> </param> <param> <key>bw0</key> <value>0</value> </param> <param> <key>dc_offset_mode0</key> <value>0</value> </param> <param> <key>corr0</key> <value>0</value> </param> <param> <key>freq0</key> <value>freq_tune</value> </param> <param> <key>gain_mode0</key> <value>False</value> </param> <param> <key>if_gain0</key> <value>20</value> </param> <param> <key>iq_balance_mode0</key> <value>0</value> </param> <param> <key>gain0</key> <value>gain</value> </param> <param> <key>ant10</key> <value></value> </param> <param> <key>bb_gain10</key> <value>20</value> </param> <param> <key>bw10</key> <value>0</value> </param> <param> <key>dc_offset_mode10</key> <value>0</value> </param> <param> <key>corr10</key> <value>0</value> </param> <param> <key>freq10</key> <value>100e6</value> </param> <param> <key>gain_mode10</key> <value>False</value> </param> <param> <key>if_gain10</key> <value>20</value> </param> <param> <key>iq_balance_mode10</key> <value>0</value> </param> <param> <key>gain10</key> <value>10</value> </param> <param> <key>ant11</key> <value></value> </param> <param> <key>bb_gain11</key> <value>20</value> </param> <param> <key>bw11</key> <value>0</value> </param> <param> <key>dc_offset_mode11</key> <value>0</value> </param> <param> <key>corr11</key> <value>0</value> </param> <param> <key>freq11</key> <value>100e6</value> </param> <param> <key>gain_mode11</key> <value>False</value> </param> <param> <key>if_gain11</key> <value>20</value> </param> <param> <key>iq_balance_mode11</key> <value>0</value> </param> <param> <key>gain11</key> <value>10</value> </param> <param> <key>ant12</key> <value></value> </param> <param> <key>bb_gain12</key> <value>20</value> </param> <param> <key>bw12</key> <value>0</value> </param> <param> <key>dc_offset_mode12</key> <value>0</value> </param> <param> <key>corr12</key> <value>0</value> </param> <param> <key>freq12</key> <value>100e6</value> </param> <param> <key>gain_mode12</key> <value>False</value> </param> <param> <key>if_gain12</key> <value>20</value> </param> <param> <key>iq_balance_mode12</key> <value>0</value> </param> <param> <key>gain12</key> <value>10</value> </param> <param> <key>ant13</key> <value></value> </param> <param> <key>bb_gain13</key> <value>20</value> </param> <param> <key>bw13</key> <value>0</value> </param> <param> <key>dc_offset_mode13</key> <value>0</value> </param> <param> <key>corr13</key> <value>0</value> </param> <param> <key>freq13</key> <value>100e6</value> </param> <param> <key>gain_mode13</key> <value>False</value> </param> <param> <key>if_gain13</key> <value>20</value> </param> <param> <key>iq_balance_mode13</key> <value>0</value> </param> <param> <key>gain13</key> <value>10</value> </param> <param> <key>ant14</key> <value></value> </param> <param> <key>bb_gain14</key> <value>20</value> </param> <param> <key>bw14</key> <value>0</value> </param> <param> <key>dc_offset_mode14</key> <value>0</value> </param> <param> <key>corr14</key> <value>0</value> </param> <param> <key>freq14</key> <value>100e6</value> </param> <param> <key>gain_mode14</key> <value>False</value> </param> <param> <key>if_gain14</key> <value>20</value> </param> <param> <key>iq_balance_mode14</key> <value>0</value> </param> <param> <key>gain14</key> <value>10</value> </param> <param> <key>ant15</key> <value></value> </param> <param> <key>bb_gain15</key> <value>20</value> </param> <param> <key>bw15</key> <value>0</value> </param> <param> <key>dc_offset_mode15</key> <value>0</value> </param> <param> <key>corr15</key> <value>0</value> </param> <param> <key>freq15</key> <value>100e6</value> </param> <param> <key>gain_mode15</key> <value>False</value> </param> <param> <key>if_gain15</key> <value>20</value> </param> <param> <key>iq_balance_mode15</key> <value>0</value> </param> <param> <key>gain15</key> <value>10</value> </param> <param> <key>ant16</key> <value></value> </param> <param> <key>bb_gain16</key> <value>20</value> </param> <param> <key>bw16</key> <value>0</value> </param> <param> <key>dc_offset_mode16</key> <value>0</value> </param> <param> <key>corr16</key> <value>0</value> </param> <param> <key>freq16</key> <value>100e6</value> </param> <param> <key>gain_mode16</key> <value>False</value> </param> <param> <key>if_gain16</key> <value>20</value> </param> <param> <key>iq_balance_mode16</key> <value>0</value> </param> <param> <key>gain16</key> <value>10</value> </param> <param> <key>ant17</key> <value></value> </param> <param> <key>bb_gain17</key> <value>20</value> </param> <param> <key>bw17</key> <value>0</value> </param> <param> <key>dc_offset_mode17</key> <value>0</value> </param> <param> <key>corr17</key> <value>0</value> </param> <param> <key>freq17</key> <value>100e6</value> </param> <param> <key>gain_mode17</key> <value>False</value> </param> <param> <key>if_gain17</key> <value>20</value> </param> <param> <key>iq_balance_mode17</key> <value>0</value> </param> <param> <key>gain17</key> <value>10</value> </param> <param> <key>ant18</key> <value></value> </param> <param> <key>bb_gain18</key> <value>20</value> </param> <param> <key>bw18</key> <value>0</value> </param> <param> <key>dc_offset_mode18</key> <value>0</value> </param> <param> <key>corr18</key> <value>0</value> </param> <param> <key>freq18</key> <value>100e6</value> </param> <param> <key>gain_mode18</key> <value>False</value> </param> <param> <key>if_gain18</key> <value>20</value> </param> <param> <key>iq_balance_mode18</key> <value>0</value> </param> <param> <key>gain18</key> <value>10</value> </param> <param> <key>ant19</key> <value></value> </param> <param> <key>bb_gain19</key> <value>20</value> </param> <param> <key>bw19</key> <value>0</value> </param> <param> <key>dc_offset_mode19</key> <value>0</value> </param> <param> <key>corr19</key> <value>0</value> </param> <param> <key>freq19</key> <value>100e6</value> </param> <param> <key>gain_mode19</key> <value>False</value> </param> <param> <key>if_gain19</key> <value>20</value> </param> <param> <key>iq_balance_mode19</key> <value>0</value> </param> <param> <key>gain19</key> <value>10</value> </param> <param> <key>ant1</key> <value></value> </param> <param> <key>bb_gain1</key> <value>20</value> </param> <param> <key>bw1</key> <value>0</value> </param> <param> <key>dc_offset_mode1</key> <value>0</value> </param> <param> <key>corr1</key> <value>0</value> </param> <param> <key>freq1</key> <value>100e6</value> </param> <param> <key>gain_mode1</key> <value>False</value> </param> <param> <key>if_gain1</key> <value>20</value> </param> <param> <key>iq_balance_mode1</key> <value>0</value> </param> <param> <key>gain1</key> <value>10</value> </param> <param> <key>ant20</key> <value></value> </param> <param> <key>bb_gain20</key> <value>20</value> </param> <param> <key>bw20</key> <value>0</value> </param> <param> <key>dc_offset_mode20</key> <value>0</value> </param> <param> <key>corr20</key> <value>0</value> </param> <param> <key>freq20</key> <value>100e6</value> </param> <param> <key>gain_mode20</key> <value>False</value> </param> <param> <key>if_gain20</key> <value>20</value> </param> <param> <key>iq_balance_mode20</key> <value>0</value> </param> <param> <key>gain20</key> <value>10</value> </param> <param> <key>ant21</key> <value></value> </param> <param> <key>bb_gain21</key> <value>20</value> </param> <param> <key>bw21</key> <value>0</value> </param> <param> <key>dc_offset_mode21</key> <value>0</value> </param> <param> <key>corr21</key> <value>0</value> </param> <param> <key>freq21</key> <value>100e6</value> </param> <param> <key>gain_mode21</key> <value>False</value> </param> <param> <key>if_gain21</key> <value>20</value> </param> <param> <key>iq_balance_mode21</key> <value>0</value> </param> <param> <key>gain21</key> <value>10</value> </param> <param> <key>ant22</key> <value></value> </param> <param> <key>bb_gain22</key> <value>20</value> </param> <param> <key>bw22</key> <value>0</value> </param> <param> <key>dc_offset_mode22</key> <value>0</value> </param> <param> <key>corr22</key> <value>0</value> </param> <param> <key>freq22</key> <value>100e6</value> </param> <param> <key>gain_mode22</key> <value>False</value> </param> <param> <key>if_gain22</key> <value>20</value> </param> <param> <key>iq_balance_mode22</key> <value>0</value> </param> <param> <key>gain22</key> <value>10</value> </param> <param> <key>ant23</key> <value></value> </param> <param> <key>bb_gain23</key> <value>20</value> </param> <param> <key>bw23</key> <value>0</value> </param> <param> <key>dc_offset_mode23</key> <value>0</value> </param> <param> <key>corr23</key> <value>0</value> </param> <param> <key>freq23</key> <value>100e6</value> </param> <param> <key>gain_mode23</key> <value>False</value> </param> <param> <key>if_gain23</key> <value>20</value> </param> <param> <key>iq_balance_mode23</key> <value>0</value> </param> <param> <key>gain23</key> <value>10</value> </param> <param> <key>ant24</key> <value></value> </param> <param> <key>bb_gain24</key> <value>20</value> </param> <param> <key>bw24</key> <value>0</value> </param> <param> <key>dc_offset_mode24</key> <value>0</value> </param> <param> <key>corr24</key> <value>0</value> </param> <param> <key>freq24</key> <value>100e6</value> </param> <param> <key>gain_mode24</key> <value>False</value> </param> <param> <key>if_gain24</key> <value>20</value> </param> <param> <key>iq_balance_mode24</key> <value>0</value> </param> <param> <key>gain24</key> <value>10</value> </param> <param> <key>ant25</key> <value></value> </param> <param> <key>bb_gain25</key> <value>20</value> </param> <param> <key>bw25</key> <value>0</value> </param> <param> <key>dc_offset_mode25</key> <value>0</value> </param> <param> <key>corr25</key> <value>0</value> </param> <param> <key>freq25</key> <value>100e6</value> </param> <param> <key>gain_mode25</key> <value>False</value> </param> <param> <key>if_gain25</key> <value>20</value> </param> <param> <key>iq_balance_mode25</key> <value>0</value> </param> <param> <key>gain25</key> <value>10</value> </param> <param> <key>ant26</key> <value></value> </param> <param> <key>bb_gain26</key> <value>20</value> </param> <param> <key>bw26</key> <value>0</value> </param> <param> <key>dc_offset_mode26</key> <value>0</value> </param> <param> <key>corr26</key> <value>0</value> </param> <param> <key>freq26</key> <value>100e6</value> </param> <param> <key>gain_mode26</key> <value>False</value> </param> <param> <key>if_gain26</key> <value>20</value> </param> <param> <key>iq_balance_mode26</key> <value>0</value> </param> <param> <key>gain26</key> <value>10</value> </param> <param> <key>ant27</key> <value></value> </param> <param> <key>bb_gain27</key> <value>20</value> </param> <param> <key>bw27</key> <value>0</value> </param> <param> <key>dc_offset_mode27</key> <value>0</value> </param> <param> <key>corr27</key> <value>0</value> </param> <param> <key>freq27</key> <value>100e6</value> </param> <param> <key>gain_mode27</key> <value>False</value> </param> <param> <key>if_gain27</key> <value>20</value> </param> <param> <key>iq_balance_mode27</key> <value>0</value> </param> <param> <key>gain27</key> <value>10</value> </param> <param> <key>ant28</key> <value></value> </param> <param> <key>bb_gain28</key> <value>20</value> </param> <param> <key>bw28</key> <value>0</value> </param> <param> <key>dc_offset_mode28</key> <value>0</value> </param> <param> <key>corr28</key> <value>0</value> </param> <param> <key>freq28</key> <value>100e6</value> </param> <param> <key>gain_mode28</key> <value>False</value> </param> <param> <key>if_gain28</key> <value>20</value> </param> <param> <key>iq_balance_mode28</key> <value>0</value> </param> <param> <key>gain28</key> <value>10</value> </param> <param> <key>ant29</key> <value></value> </param> <param> <key>bb_gain29</key> <value>20</value> </param> <param> <key>bw29</key> <value>0</value> </param> <param> <key>dc_offset_mode29</key> <value>0</value> </param> <param> <key>corr29</key> <value>0</value> </param> <param> <key>freq29</key> <value>100e6</value> </param> <param> <key>gain_mode29</key> <value>False</value> </param> <param> <key>if_gain29</key> <value>20</value> </param> <param> <key>iq_balance_mode29</key> <value>0</value> </param> <param> <key>gain29</key> <value>10</value> </param> <param> <key>ant2</key> <value></value> </param> <param> <key>bb_gain2</key> <value>20</value> </param> <param> <key>bw2</key> <value>0</value> </param> <param> <key>dc_offset_mode2</key> <value>0</value> </param> <param> <key>corr2</key> <value>0</value> </param> <param> <key>freq2</key> <value>100e6</value> </param> <param> <key>gain_mode2</key> <value>False</value> </param> <param> <key>if_gain2</key> <value>20</value> </param> <param> <key>iq_balance_mode2</key> <value>0</value> </param> <param> <key>gain2</key> <value>10</value> </param> <param> <key>ant30</key> <value></value> </param> <param> <key>bb_gain30</key> <value>20</value> </param> <param> <key>bw30</key> <value>0</value> </param> <param> <key>dc_offset_mode30</key> <value>0</value> </param> <param> <key>corr30</key> <value>0</value> </param> <param> <key>freq30</key> <value>100e6</value> </param> <param> <key>gain_mode30</key> <value>False</value> </param> <param> <key>if_gain30</key> <value>20</value> </param> <param> <key>iq_balance_mode30</key> <value>0</value> </param> <param> <key>gain30</key> <value>10</value> </param> <param> <key>ant31</key> <value></value> </param> <param> <key>bb_gain31</key> <value>20</value> </param> <param> <key>bw31</key> <value>0</value> </param> <param> <key>dc_offset_mode31</key> <value>0</value> </param> <param> <key>corr31</key> <value>0</value> </param> <param> <key>freq31</key> <value>100e6</value> </param> <param> <key>gain_mode31</key> <value>False</value> </param> <param> <key>if_gain31</key> <value>20</value> </param> <param> <key>iq_balance_mode31</key> <value>0</value> </param> <param> <key>gain31</key> <value>10</value> </param> <param> <key>ant3</key> <value></value> </param> <param> <key>bb_gain3</key> <value>20</value> </param> <param> <key>bw3</key> <value>0</value> </param> <param> <key>dc_offset_mode3</key> <value>0</value> </param> <param> <key>corr3</key> <value>0</value> </param> <param> <key>freq3</key> <value>100e6</value> </param> <param> <key>gain_mode3</key> <value>False</value> </param> <param> <key>if_gain3</key> <value>20</value> </param> <param> <key>iq_balance_mode3</key> <value>0</value> </param> <param> <key>gain3</key> <value>10</value> </param> <param> <key>ant4</key> <value></value> </param> <param> <key>bb_gain4</key> <value>20</value> </param> <param> <key>bw4</key> <value>0</value> </param> <param> <key>dc_offset_mode4</key> <value>0</value> </param> <param> <key>corr4</key> <value>0</value> </param> <param> <key>freq4</key> <value>100e6</value> </param> <param> <key>gain_mode4</key> <value>False</value> </param> <param> <key>if_gain4</key> <value>20</value> </param> <param> <key>iq_balance_mode4</key> <value>0</value> </param> <param> <key>gain4</key> <value>10</value> </param> <param> <key>ant5</key> <value></value> </param> <param> <key>bb_gain5</key> <value>20</value> </param> <param> <key>bw5</key> <value>0</value> </param> <param> <key>dc_offset_mode5</key> <value>0</value> </param> <param> <key>corr5</key> <value>0</value> </param> <param> <key>freq5</key> <value>100e6</value> </param> <param> <key>gain_mode5</key> <value>False</value> </param> <param> <key>if_gain5</key> <value>20</value> </param> <param> <key>iq_balance_mode5</key> <value>0</value> </param> <param> <key>gain5</key> <value>10</value> </param> <param> <key>ant6</key> <value></value> </param> <param> <key>bb_gain6</key> <value>20</value> </param> <param> <key>bw6</key> <value>0</value> </param> <param> <key>dc_offset_mode6</key> <value>0</value> </param> <param> <key>corr6</key> <value>0</value> </param> <param> <key>freq6</key> <value>100e6</value> </param> <param> <key>gain_mode6</key> <value>False</value> </param> <param> <key>if_gain6</key> <value>20</value> </param> <param> <key>iq_balance_mode6</key> <value>0</value> </param> <param> <key>gain6</key> <value>10</value> </param> <param> <key>ant7</key> <value></value> </param> <param> <key>bb_gain7</key> <value>20</value> </param> <param> <key>bw7</key> <value>0</value> </param> <param> <key>dc_offset_mode7</key> <value>0</value> </param> <param> <key>corr7</key> <value>0</value> </param> <param> <key>freq7</key> <value>100e6</value> </param> <param> <key>gain_mode7</key> <value>False</value> </param> <param> <key>if_gain7</key> <value>20</value> </param> <param> <key>iq_balance_mode7</key> <value>0</value> </param> <param> <key>gain7</key> <value>10</value> </param> <param> <key>ant8</key> <value></value> </param> <param> <key>bb_gain8</key> <value>20</value> </param> <param> <key>bw8</key> <value>0</value> </param> <param> <key>dc_offset_mode8</key> <value>0</value> </param> <param> <key>corr8</key> <value>0</value> </param> <param> <key>freq8</key> <value>100e6</value> </param> <param> <key>gain_mode8</key> <value>False</value> </param> <param> <key>if_gain8</key> <value>20</value> </param> <param> <key>iq_balance_mode8</key> <value>0</value> </param> <param> <key>gain8</key> <value>10</value> </param> <param> <key>ant9</key> <value></value> </param> <param> <key>bb_gain9</key> <value>20</value> </param> <param> <key>bw9</key> <value>0</value> </param> <param> <key>dc_offset_mode9</key> <value>0</value> </param> <param> <key>corr9</key> <value>0</value> </param> <param> <key>freq9</key> <value>100e6</value> </param> <param> <key>gain_mode9</key> <value>False</value> </param> <param> <key>if_gain9</key> <value>20</value> </param> <param> <key>iq_balance_mode9</key> <value>0</value> </param> <param> <key>gain9</key> <value>10</value> </param> <param> <key>comment</key> <value></value> </param> <param> <key>affinity</key> <value></value> </param> <param> <key>args</key> <value></value> </param> <param> <key>_enabled</key> <value>1</value> </param> <param> <key>_coordinate</key> <value>(24, 272)</value> </param> <param> <key>_rotation</key> <value>0</value> </param> <param> <key>id</key> <value>rtlsdr_source_0</value> </param> <param> <key>maxoutbuf</key> <value>0</value> </param> <param> <key>clock_source0</key> <value></value> </param> <param> <key>time_source0</key> <value></value> </param> <param> <key>clock_source1</key> <value></value> </param> <param> <key>time_source1</key> <value></value> </param> <param> <key>clock_source2</key> <value></value> </param> <param> <key>time_source2</key> <value></value> </param> <param> <key>clock_source3</key> <value></value> </param> <param> <key>time_source3</key> <value></value> </param> <param> <key>clock_source4</key> <value></value> </param> <param> <key>time_source4</key> <value></value> </param> <param> <key>clock_source5</key> <value></value> </param> <param> <key>time_source5</key> <value></value> </param> <param> <key>clock_source6</key> <value></value> </param> <param> <key>time_source6</key> <value></value> </param> <param> <key>clock_source7</key> <value></value> </param> <param> <key>time_source7</key> <value></value> </param> <param> <key>minoutbuf</key> <value>0</value> </param> <param> <key>nchan</key> <value>1</value> </param> <param> <key>num_mboards</key> <value>1</value> </param> <param> <key>type</key> <value>fc32</value> </param> <param> <key>sample_rate</key> <value>samp_rate</value> </param> <param> <key>sync</key> <value></value> </param> </block> <block> <key>wxgui_fftsink2</key> <param> <key>avg_alpha</key> <value>0.8</value> </param> <param> <key>average</key> <value>True</value> </param> <param> <key>baseband_freq</key> <value>0</value> </param> <param> <key>alias</key> <value></value> </param> <param> <key>comment</key> <value></value> </param> <param> <key>affinity</key> <value></value> </param> <param> <key>_enabled</key> <value>True</value> </param> <param> <key>fft_size</key> <value>1024</value> </param> <param> <key>freqvar</key> <value>None</value> </param> <param> <key>_coordinate</key> <value>(1056, 56)</value> </param> <param> <key>_rotation</key> <value>0</value> </param> <param> <key>grid_pos</key> <value></value> </param> <param> <key>id</key> <value>wxgui_fftsink2_0</value> </param> <param> <key>notebook</key> <value>nb, 0</value> </param> <param> <key>peak_hold</key> <value>False</value> </param> <param> <key>ref_level</key> <value>-30</value> </param> <param> <key>ref_scale</key> <value>2.0</value> </param> <param> <key>fft_rate</key> <value>15</value> </param> <param> <key>samp_rate</key> <value>samp_rate</value> </param> <param> <key>title</key> <value>Baseband</value> </param> <param> <key>type</key> <value>complex</value> </param> <param> <key>win_size</key> <value></value> </param> <param> <key>win</key> <value>None</value> </param> <param> <key>y_divs</key> <value>10</value> </param> <param> <key>y_per_div</key> <value>10</value> </param> </block> <block> <key>wxgui_fftsink2</key> <param> <key>avg_alpha</key> <value>0.8</value> </param> <param> <key>average</key> <value>True</value> </param> <param> <key>baseband_freq</key> <value>0</value> </param> <param> <key>alias</key> <value></value> </param> <param> <key>comment</key> <value></value> </param> <param> <key>affinity</key> <value></value> </param> <param> <key>_enabled</key> <value>True</value> </param> <param> <key>fft_size</key> <value>1024</value> </param> <param> <key>freqvar</key> <value>None</value> </param> <param> <key>_coordinate</key> <value>(1056, 280)</value> </param> <param> <key>_rotation</key> <value>0</value> </param> <param> <key>grid_pos</key> <value></value> </param> <param> <key>id</key> <value>wxgui_fftsink2_0_0</value> </param> <param> <key>notebook</key> <value>nb, 1</value> </param> <param> <key>peak_hold</key> <value>False</value> </param> <param> <key>ref_level</key> <value>0</value> </param> <param> <key>ref_scale</key> <value>2.0</value> </param> <param> <key>fft_rate</key> <value>15</value> </param> <param> <key>samp_rate</key> <value>baseband_rate</value> </param> <param> <key>title</key> <value>FM Demod</value> </param> <param> <key>type</key> <value>float</value> </param> <param> <key>win_size</key> <value></value> </param> <param> <key>win</key> <value>None</value> </param> <param> <key>y_divs</key> <value>10</value> </param> <param> <key>y_per_div</key> <value>10</value> </param> </block> <block> <key>wxgui_scopesink2</key> <param> <key>ac_couple</key> <value>False</value> </param> <param> <key>alias</key> <value></value> </param> <param> <key>comment</key> <value></value> </param> <param> <key>affinity</key> <value></value> </param> <param> <key>_enabled</key> <value>True</value> </param> <param> <key>_coordinate</key> <value>(1056, 500)</value> </param> <param> <key>_rotation</key> <value>0</value> </param> <param> <key>grid_pos</key> <value></value> </param> <param> <key>id</key> <value>wxgui_scopesink2_1</value> </param> <param> <key>notebook</key> <value>nb,7</value> </param> <param> <key>num_inputs</key> <value>1</value> </param> <param> <key>samp_rate</key> <value>2375</value> </param> <param> <key>t_scale</key> <value>0</value> </param> <param> <key>title</key> <value>Scope Plot</value> </param> <param> <key>trig_mode</key> <value>wxgui.TRIG_MODE_AUTO</value> </param> <param> <key>type</key> <value>complex</value> </param> <param> <key>v_offset</key> <value>0</value> </param> <param> <key>v_scale</key> <value>0.4</value> </param> <param> <key>win_size</key> <value></value> </param> <param> <key>xy_mode</key> <value>True</value> </param> <param> <key>y_axis_label</key> <value>Counts</value> </param> </block> <connection> <source_block_id>analog_wfm_rcv_0</source_block_id> <sink_block_id>freq_xlating_fir_filter_xxx_1</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>analog_wfm_rcv_0</source_block_id> <sink_block_id>wxgui_fftsink2_0_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>blocks_complex_to_real_0</source_block_id> <sink_block_id>digital_binary_slicer_fb_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>blocks_keep_one_in_n_0</source_block_id> <sink_block_id>digital_diff_decoder_bb_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>digital_binary_slicer_fb_0</source_block_id> <sink_block_id>blocks_keep_one_in_n_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>digital_diff_decoder_bb_0</source_block_id> <sink_block_id>gr_rds_decoder_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>digital_mpsk_receiver_cc_0</source_block_id> <sink_block_id>blocks_complex_to_real_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>digital_mpsk_receiver_cc_0</source_block_id> <sink_block_id>wxgui_scopesink2_1</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>freq_xlating_fir_filter_xxx_0</source_block_id> <sink_block_id>analog_wfm_rcv_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>freq_xlating_fir_filter_xxx_0</source_block_id> <sink_block_id>wxgui_fftsink2_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>freq_xlating_fir_filter_xxx_1</source_block_id> <sink_block_id>root_raised_cosine_filter_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>gr_rds_decoder_0</source_block_id> <sink_block_id>gr_rds_parser_0</sink_block_id> <source_key>out</source_key> <sink_key>in</sink_key> </connection> <connection> <source_block_id>gr_rds_parser_0</source_block_id> <sink_block_id>gr_rds_panel_0</sink_block_id> <source_key>out</source_key> <sink_key>in</sink_key> </connection> <connection> <source_block_id>root_raised_cosine_filter_0</source_block_id> <sink_block_id>digital_mpsk_receiver_cc_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> <connection> <source_block_id>rtlsdr_source_0</source_block_id> <sink_block_id>freq_xlating_fir_filter_xxx_0</sink_block_id> <source_key>0</source_key> <sink_key>0</sink_key> </connection> </flow_graph>