[New feature] Added function prototype for olivia mfsk encoding

firmware/inc/mfsk.h

@@ -0,0 +1,32 @@
+/*
+ * Bit-bangs MFSK
+ * Copyright (C) 2014  Richard Meadows <richardeoin>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef MFSK_H
+#define MFSK_H
+
+#include "samd20.h"
+
+void olivia_mfsk_encode_block(char* buffer, int8_t* tones);
+
+#endif /* MFSK_H */

firmware/src/mfsk.c

@@ -0,0 +1,99 @@
+/*
+ * Functions for MFSK encoding / decoding
+ * Copyright (C) 2014  Richard Meadows <richardeoin>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "samd20.h"
+#include "msfk.h"
+
+//#define OLIVIA_MFSK_ENCODE_TEST
+#ifdef OLIVIA_MFSK_ENCODE_TEST
+#include <stdint.h>
+#endif
+
+
+static const uint64_t ScramblingCodeOlivia	= 0xE257E6D0291574ECLL;
+static const uint64_t ScramblingCodeContestia	= 0xEDB88320LL;
+
+/**
+ * USEFUL RESOURES =============================================================
+ *
+ * http://en.wikipedia.org/wiki/Olivia_MFSK
+ * http://www.arrl.org/olivia
+ *
+ * Also, although without images:
+ * http://web.archive.org/web/20070927210543/http://homepage.sunrise.ch/mysunrise/jalocha/fht_coding.htm
+ *
+ * Useful guide to the differences between olivia and contestia
+ * (ultimately we'd like to support both):
+ * http://f1ult.free.fr/DIGIMODES/MULTIPSK/contestia_rttym_en.htm
+ *
+ * Also dl-fldigi's source might be helpful:
+ * https://github.com/jamescoxon/dl-fldigi/blob/master/src/include/jalocha/pj_mfsk.h
+ */
+
+/**
+ * This function encodes a single block of Olivia MFSK
+ *
+ * It takes a buffer of ASCII-encoded text and returns an array of
+ * tones to transmit.
+ */
+void olivia_mfsk_encode_block(char* buffer, int8_t* tones)
+{
+  size_t bits_per_character = 7;
+
+  size_t bits_per_symbol = 5; /* That is, there are 2^5=32 tones */
+  size_t symbols_per_block = 64;
+
+
+
+
+  /* TODO! */
+
+
+
+
+}
+
+#ifdef OLIVIA_MFSK_ENCODE_TEST
+void main(void)
+{
+  /* Define a test string */
+  char test_string[6];
+  test_string = "HELLO";
+
+  /* Define a buffer for the tones produced */
+  int8_t tones[64];
+
+
+  olivia_mfsk_encode_block(buffer, tones);
+
+
+  /* Debug printout */
+  for (int i = 0; i < sizeof(tones)/sizeof(int8_t); i++) {
+    printf("%d ", tones[i]);
+  }
+  printf("\n");
+}
+#endif