SPIDMXParser.h

/*
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * 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 Library General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * SPIDMXParser.h
 * This parses a SPI buffer into a DmxBuffer and notifies a callback when a
 * packet is received completely.
 * Copyright (C) 2017 Florian Edelmann
 */

#ifndef PLUGINS_SPIDMX_SPIDMXPARSER_H_
#define PLUGINS_SPIDMX_SPIDMXPARSER_H_

#include "ola/Callback.h"
#include "ola/DmxBuffer.h"
#include "ola/base/Macro.h"

namespace ola {
namespace plugin {
namespace spidmx {

class SPIDMXParser {
 public:
 SPIDMXParser(DmxBuffer *buffer, Callback0<void> *callback)
 : m_dmx_buffer(buffer),
 m_callback(callback),
 m_state(WAIT_FOR_BREAK), // reset in ChangeState()
 m_chunk(NULL), // reset in ParseDmx()
 m_chunk_spi_bytecount(0), // first reset in ParseDmx()
 m_state_spi_bitcount(0), // first reset in ChangeState()
 m_current_dmx_value(0), // first reset in InDataStartbit()
 m_channel_count(0), // first reset in ChangeState()
 m_sampling_position(0) { // reset in InDataStartbit()
 }
 void ParseDmx(uint8_t *buffer, uint64_t chunksize);
 void SetCallback(Callback0<void> *callback) {
 m_callback = callback;
 }

 private:
 typedef enum {
 WAIT_FOR_BREAK,
 IN_BREAK,
 WAIT_FOR_MAB,
 IN_MAB,
 IN_STARTCODE,
 IN_STARTCODE_STOPBITS,
 IN_DATA_STARTBIT,
 IN_DATA_BITS,
 IN_DATA_STOPBITS
 } dmx_state_t;

 // helper functions
 int8_t DetectFallingEdge(uint8_t byte);
 int8_t DetectRisingEdge(uint8_t byte);

 void ChangeState(SPIDMXParser::dmx_state_t new_state);
 void PacketComplete();

 // handle one state each
 void WaitForBreak();
 void InBreak();
 void WaitForMab();
 void InMab();
 void InStartcode();
 void InStartcodeStopbits();
 void InDataStartbit();
 void InDataBits();
 void InLastDataBit();
 void InDataStopbits();

 DmxBuffer *m_dmx_buffer;

 Callback0<void> *m_callback;

 SPIDMXParser::dmx_state_t m_state;

 uint8_t *m_chunk;

 uint64_t m_chunk_spi_bytecount;

 uint64_t m_state_spi_bitcount;

 uint8_t m_current_dmx_value;

 int16_t m_channel_count;

 uint8_t m_sampling_position;

 DISALLOW_COPY_AND_ASSIGN(SPIDMXParser);
};

} // namespace spidmx
} // namespace plugin
} // namespace ola
#endif // PLUGINS_SPIDMX_SPIDMXPARSER_H_