X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fnet%2Fafsk.h;h=d5eb272db1dc16e903c4f7d2ce433a06a15297df;hb=911d2706a86d326786bfe721dcc3d63aeade7f28;hp=49d5ce7ba1261fd956511b5fbdada5c6c6aa38d0;hpb=192418d2e34d644d7f652378f68ff3b2fed183e0;p=bertos.git

diff --git a/bertos/net/afsk.h b/bertos/net/afsk.h
index 49d5ce7b..d5eb272d 100644
--- a/bertos/net/afsk.h
+++ b/bertos/net/afsk.h
@@ -32,24 +32,166 @@
  *
  * \brief AFSK1200 modem.
  *
- * \version $Id$
  * \author Francesco Sacchi <asterix@develer.com>
- * 
+ *
  * $WIZ$ module_name = "afsk"
  * $WIZ$ module_configuration = "bertos/cfg/cfg_afsk.h"
  * $WIZ$ module_depends = "timer", "kfile"
+ * $WIZ$ module_hw = "bertos/hw/hw_afsk.h"
  */
 
-#ifndef DRV_AFSK_H
-#define DRV_AFSK_H
+#ifndef NET_AFSK_H
+#define NET_AFSK_H
 
-#include <kern/kfile.h>
-#include <cfg/compiler.h>
+#include "cfg/cfg_afsk.h"
 #include "hw/hw_afsk.h"
 
+#include <io/kfile.h>
+#include <cfg/compiler.h>
+#include <struct/fifobuf.h>
+
+
+
+/**
+ * ADC sample rate.
+ * The demodulator filters are designed to work at this frequency.
+ * If you need to change this remember to update afsk_adc_isr().
+ */
+#define SAMPLERATE 9600
+
+/**
+ * Bitrate of the received/transmitted data.
+ * The demodulator filters and decoderes are designed to work at this frequency.
+ * If you need to change this remember to update afsk_adc_isr().
+ */
+#define BITRATE    1200
+
+#define SAMPLEPERBIT (SAMPLERATE / BITRATE)
+
+/**
+ * HDLC (High-Level Data Link Control) context.
+ * Maybe to be moved in a separate HDLC module one day.
+ */
+typedef struct Hdlc
+{
+	uint8_t demod_bits; ///< Bitstream from the demodulator.
+	uint8_t bit_idx;    ///< Current received bit.
+	uint8_t currchar;   ///< Current received character.
+	bool rxstart;       ///< True if an HDLC_FLAG char has been found in the bitstream.
+} Hdlc;
+
+/**
+ * RX FIFO buffer full error.
+ */
+#define AFSK_RXFIFO_OVERRUN BV(0)
+
+/**
+ * AFSK1200 modem context.
+ */
 typedef struct Afsk
 {
-  KFile fd;
+	/** Base "class" */
+	KFile fd;
+
+	/** ADC channel to be used by the demodulator */
+	int adc_ch;
+
+	/** DAC channel to be used by the modulator */
+	int dac_ch;
+
+	/** Current sample of bit for output data. */
+	uint8_t sample_count;
+
+	/** Current character to be modulated */
+	uint8_t curr_out;
+
+	/** Mask of current modulated bit */
+	uint8_t tx_bit;
+
+	/** True if bit stuff is allowed, false otherwise */
+	bool bit_stuff;
+
+	/** Counter for bit stuffing */
+	uint8_t stuff_cnt;
+	/**
+	 * DDS phase accumulator for generating modulated data.
+	 */
+	uint16_t phase_acc;
+
+	/** Current phase increment for current modulated bit */
+	uint16_t phase_inc;
+
+	/** Delay line used to delay samples by (SAMPLEPERBIT / 2) */
+	FIFOBuffer delay_fifo;
+
+	/**
+	 * Buffer for delay FIFO.
+	 * The 1 is added because the FIFO macros need
+	 * 1 byte more to handle a buffer (SAMPLEPERBIT / 2) bytes long.
+	 */
+	int8_t delay_buf[SAMPLEPERBIT / 2 + 1];
+
+	/** FIFO for received data */
+	FIFOBuffer rx_fifo;
+
+	/** FIFO rx buffer */
+	uint8_t rx_buf[CONFIG_AFSK_RX_BUFLEN];
+
+	/** FIFO for transmitted data */
+	FIFOBuffer tx_fifo;
+
+	/** FIFO tx buffer */
+	uint8_t tx_buf[CONFIG_AFSK_TX_BUFLEN];
+
+	/** IIR filter X cells, used to filter sampled data by the demodulator */
+	int16_t iir_x[2];
+
+	/** IIR filter Y cells, used to filter sampled data by the demodulator */
+	int16_t iir_y[2];
+
+	/**
+	 * Bits sampled by the demodulator are here.
+	 * Since ADC samplerate is higher than the bitrate, the bits here are
+	 * SAMPLEPERBIT times the bitrate.
+	 */
+	uint8_t sampled_bits;
+
+	/**
+	 * Current phase, needed to know when the bitstream at ADC speed
+	 * should be sampled.
+	 */
+	int8_t curr_phase;
+
+	/** Bits found by the demodulator at the correct bitrate speed. */
+	uint8_t found_bits;
+
+	/** True while modem sends data */
+	volatile bool sending;
+
+	/**
+	 * AFSK modem status.
+	 * If 0 all is ok, otherwise errors are present.
+	 */
+	volatile int status;
+
+	/** Hdlc context */
+	Hdlc hdlc;
+
+	/**
+	 * Preamble length.
+	 * When the AFSK modem wants to send data, before sending the actual data,
+	 * shifts out preamble_len HDLC_FLAG characters.
+	 * This helps to synchronize the demodulator filters on the receiver side.
+	 */
+	uint16_t preamble_len;
+
+	/**
+	 * Trailer length.
+	 * After sending the actual data, the AFSK shifts out
+	 * trailer_len HDLC_FLAG characters.
+	 * This helps to synchronize the demodulator filters on the receiver side.
+	 */
+	uint16_t trailer_len;
 } Afsk;
 
 #define KFT_AFSK MAKE_ID('A', 'F', 'S', 'K')
@@ -60,10 +202,23 @@ INLINE Afsk *AFSK_CAST(KFile *fd)
   return (Afsk *)fd;
 }
 
-void afsk_init(Afsk *af);
 
-#define HDLC_FLAG  0x7E
-#define HDLC_RESET 0x7F
-#define AFSK_ESC   0x1B
+void afsk_adc_isr(Afsk *af, int8_t sample);
+uint8_t afsk_dac_isr(Afsk *af);
+void afsk_init(Afsk *af, int adc_ch, int dac_ch);
+
+
+/**
+ * \name Afsk filter types.
+ * $WIZ$ afsk_filter_list = "AFSK_BUTTERWORTH", "AFSK_CHEBYSHEV"
+ * \{
+ */
+#define AFSK_BUTTERWORTH  0
+#define AFSK_CHEBYSHEV    1
+/* \} */
+
+int afsk_testSetup(void);
+int afsk_testRun(void);
+int afsk_testTearDown(void);
 
-#endif
+#endif /* NET_AFSK_H */