Files
GnuRadio/gr-jay/lib/preamble_sync_impl.cc
T
2019-01-08 16:20:37 +00:00

159 lines
3.3 KiB
C++

/* -*- c++ -*- */
/*
* Copyright 2019 Jay Arrowfield.
*
* This 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, or (at your option)
* any later version.
*
* This software 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 software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gnuradio/io_signature.h>
#include "preamble_sync_impl.h"
namespace gr
{
namespace jay
{
preamble_sync::sptr preamble_sync::make()
{
return gnuradio::get_initial_sptr (new preamble_sync_impl());
}
/*
* The private constructor
*/
preamble_sync_impl::preamble_sync_impl()
: gr::block("preamble_sync", gr::io_signature::make(1, 1, sizeof(uint8_t)), gr::io_signature::make(1, 1, sizeof(uint8_t)))
, m_state(Init)
, m_stateNext(Init)
, m_word(0)
, m_wordCount(0)
, m_preambleCount(0)
{
}
/*
* Our virtual destructor.
*/
preamble_sync_impl::~preamble_sync_impl()
{
}
void preamble_sync_impl::forecast (int noutput_items, gr_vector_int &ninput_items_required)
{
ninput_items_required[0] = 8*noutput_items;
}
int preamble_sync_impl::general_work (int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
{
size_t const word_size = 8;
const uint8_t *in = (const uint8_t *) input_items[0];
uint8_t *out = (uint8_t *) output_items[0];
// Do <+signal processing+>
size_t i = 0;
size_t j = 0;
for (i=0; i < ninput_items[0]; i++)
{
if (in[i] == 0xFF)
{
if (m_state != Init)
{
m_state = Init;
fprintf(stderr, "Init\n");
}
continue;
}
m_word = (m_word << 1) | in[i];
if (m_wordCount != 0)
{
m_wordCount--;
continue;
}
m_word &= (typeof(m_word))(1 << word_size)-1;
m_stateNext = m_state;
switch (m_state)
{
case Init:
if (m_word != 0xCC)
{
m_wordCount = 0;
m_preambleCount = 8;
}
else
{
m_wordCount = word_size-1;
if (m_preambleCount)
{
m_preambleCount--;
}
else
{
m_stateNext = Preamble;
fprintf(stderr, "Preamble\n");
}
}
break;
case Preamble:
m_wordCount = word_size-1;
if (m_word == 0xC0)
{
m_stateNext = Sync;
fprintf(stderr, "Sync 1\n");
}
else if (m_word == 0xCF)
{
m_stateNext = Sync;
fprintf(stderr, "Sync 2\n");
}
else if (m_word == 0xF0)
{
m_wordCount = word_size/2-1;
m_stateNext = Sync;
fprintf(stderr, "Sync 3\n");
}
else if (m_word != 0xCC)
{
m_wordCount = 0;
m_stateNext = Init;
}
break;
case Sync:
m_wordCount = word_size-1;
out[j++] = m_word;
break;
}
m_state = m_stateNext;
}
// Tell runtime system how many input items we consumed on
// each input stream.
consume_each (i);
// Tell runtime system how many output items we produced.
return j;
}
} /* namespace jay */
} /* namespace gr */