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diff --git a/src/fmfsk.h b/src/fmfsk.h
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+/*---------------------------------------------------------------------------*\
+
+  FILE........: fmfsk.h
+  AUTHOR......: Brady O'Brien
+  DATE CREATED: 6 February 2016
+
+  C Implementation of 2FSK+Manchester over FM modulator/demodulator, based
+  on mancyfsk.m and fmfsk.m
+
+\*---------------------------------------------------------------------------*/
+
+/*
+  Copyright (C) 2016 David Rowe
+
+  All rights reserved.
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License version 2.1, as
+  published by the Free Software Foundation.  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 Lesser General Public License
+  along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __C2FMFSK_H
+#define __C2FMFSK_H
+
+#include <stdint.h>
+#include "comp.h"
+#include "modem_stats.h"
+
+#define FMFSK_SCALE 16383
+
+/* 
+ * fm-me-2fsk state
+ */
+struct FMFSK{
+    /* Static fmfsk parameters */
+    int Rb;             /* Manchester-encoded bitrate */
+    int Rs;             /* Raw modem symbol rate */
+    int Fs;             /* Sample rate */
+    int Ts;             /* Samples-per-symbol */
+    int N;              /* Sample processing buffer size */
+    int nsym;           /* Number of raw modem symbols processed per demod call */
+    int nbit;           /* Number of bits spit out per demod call */
+    int nmem;           /* Number of samples kept around between demod calls */
+    
+    /* State kept by demod */
+    int nin;            /* Number of samples to be demod-ed the next cycle */
+    int lodd;           /* Last integrated sample for odd bitstream generation */
+    float * oldsamps;   /* Memory of old samples to make clock-offset-tolerance possible */
+    
+    /* Stats generated by demod */
+    float norm_rx_timing; /* RX Timing, used to calculate clock offset */
+    int ppm;			/* Clock offset in parts-per-million */
+    float snr_mean;
+    
+    /* Modem stat structure */
+    struct MODEM_STATS * stats;
+};
+
+/*
+ * Create a new fmfsk modem instance.
+ * 
+ * int Fs - sample rate
+ * int Rb - non-manchester bitrate
+ * returns - new struct FMFSK on success, NULL on failure
+ */
+struct FMFSK * fmfsk_create(int Fs,int Rb);
+
+/*
+ * Destroys an fmfsk modem and deallocates memory
+ */
+void fmfsk_destroy(struct FMFSK *fmfsk);
+
+/*
+ * Deposit demod statistics into a MODEM_STATS struct
+ */
+void fmfsk_get_demod_stats(struct FMFSK *fmfsk,struct MODEM_STATS *stats);
+
+/*
+ * Returns the number of samples that must be fed to fmfsk_demod the next
+ * cycle
+ */
+uint32_t fmfsk_nin(struct FMFSK *fmfsk);
+
+/*
+ * Modulates nbit bits into N samples to be sent through an FM radio
+ * 
+ * struct FSK *fsk - FSK config/state struct, set up by fsk_create
+ * float mod_out[] - Buffer for N samples of modulated FMFSK
+ * uint8_t tx_bits[] - Buffer containing Nbits unpacked bits
+ */
+void fmfsk_mod(struct FMFSK *fmfsk, float fmfsk_out[],uint8_t bits_in[]);
+
+
+/*
+ * Demodulate some number of FMFSK samples. The number of samples to be 
+ *  demodulated can be found by calling fmfsk_nin().
+ * 
+ * struct FMFSK *fsk - FMFSK config/state struct, set up by fsk_create
+ * uint8_t rx_bits[] - Buffer for nbit unpacked bits to be written
+ * float fsk_in[] - nin samples of modualted FMFSK from an FM radio
+ */
+void fmfsk_demod(struct FMFSK *fmfsk, uint8_t rx_bits[],float fmfsk_in[]);
+
+#endif