mirror of https://github.com/markqvist/MMDVM.git
Start work on 4800 baud NXDN support.
Jonathan Naylor
parent
f32b8dc4e8
commit
a6b6219c6d
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@ -0,0 +1,50 @@
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/*
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* Copyright (C) 2016,2017,2018 by Jonathan Naylor G4KLX
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#if !defined(NXDNDEFINES_H)
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#define NXDNDEFINES_H
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const unsigned int NXDN_RADIO_SYMBOL_LENGTH = 5U; // At 24 kHz sample rate
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const unsigned int NXDN_FRAME_LENGTH_BITS = 384U;
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const unsigned int NXDN_FRAME_LENGTH_BYTES = NXDN_FRAME_LENGTH_BITS / 8U;
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const unsigned int NXDN_FRAME_LENGTH_SYMBOLS = NXDN_FRAME_LENGTH_BITS / 2U;
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const unsigned int NXDN_FRAME_LENGTH_SAMPLES = NXDN_FRAME_LENGTH_SYMBOLS * NXDN_RADIO_SYMBOL_LENGTH;
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const unsigned int NXDN_FSW_LENGTH_BITS = 20U;
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const unsigned int NXDN_FSW_LENGTH_SYMBOLS = NXDN_FSW_LENGTH_BITS / 2U;
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const unsigned int NXDN_FSW_LENGTH_SAMPLES = NXDN_FSW_LENGTH_SYMBOLS * NXDN_RADIO_SYMBOL_LENGTH;
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const uint8_t NXDN_FSW_BYTES[] = {0xCDU, 0xF5U, 0x90U};
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const uint8_t NXDN_FSW_BYTES_MASK[] = {0xFFU, 0xFFU, 0xF0U};
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const uint8_t NXDN_FSW_BYTES_LENGTH = 3U;
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const uint32_t NXDN_FSW_BITS = 0x000CDF59U;
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const uint32_t NXDN_FSW_BITS_MASK = 0x000FFFFFU;
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// C D F 5 9
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// 11 00 11 01 11 11 01 01 10 01
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// -3 +1 -3 +3 -3 -3 +3 +3 -1 +3
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const int8_t NXDN_FSW_SYMBOLS_VALUES[] = {-3, +1, -3, +3, -3, -3, +3, +3, -1, +3};
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const uint16_t NXDN_FSW_SYMBOLS = 0x014DU;
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const uint16_t NXDN_FSW_SYMBOLS_MASK = 0x03FFU;
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#endif
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@ -0,0 +1,50 @@
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/*
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* Copyright (C) 2016,2017,2018 by Jonathan Naylor G4KLX
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#if !defined(NXDNDEFINES_H)
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#define NXDNDEFINES_H
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const unsigned int NXDN_RADIO_SYMBOL_LENGTH = 5U; // At 24 kHz sample rate
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const unsigned int NXDN_FRAME_LENGTH_BITS = 384U;
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const unsigned int NXDN_FRAME_LENGTH_BYTES = NXDN_FRAME_LENGTH_BITS / 8U;
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const unsigned int NXDN_FRAME_LENGTH_SYMBOLS = NXDN_FRAME_LENGTH_BITS / 2U;
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const unsigned int NXDN_FRAME_LENGTH_SAMPLES = NXDN_FRAME_LENGTH_SYMBOLS * NXDN_RADIO_SYMBOL_LENGTH;
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const unsigned int NXDN_FSW_LENGTH_BITS = 20U;
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const unsigned int NXDN_FSW_LENGTH_SYMBOLS = NXDN_FSW_LENGTH_BITS / 2U;
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const unsigned int NXDN_FSW_LENGTH_SAMPLES = NXDN_FSW_LENGTH_SYMBOLS * NXDN_RADIO_SYMBOL_LENGTH;
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const uint8_t NXDN_FSW_BYTES[] = {0xCDU, 0xF5U, 0x90U};
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const uint8_t NXDN_FSW_BYTES_MASK[] = {0xFFU, 0xFFU, 0xF0U};
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const uint8_t NXDN_FSW_BYTES_LENGTH = 3U;
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const uint32_t NXDN_FSW_BITS = 0x000CDF59U;
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const uint32_t NXDN_FSW_BITS_MASK = 0x000FFFFFU;
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// C D F 5 9
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// 11 00 11 01 11 11 01 01 10 01
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// -3 +1 -3 +3 -3 -3 +3 +3 -1 +3
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const int8_t NXDN_FSW_SYMBOLS_VALUES[] = {-3, +1, -3, +3, -3, -3, +3, +3, -1, +3};
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const uint16_t NXDN_FSW_SYMBOLS = 0x014DU;
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const uint16_t NXDN_FSW_SYMBOLS_MASK = 0x03FFU;
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#endif
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@ -0,0 +1,398 @@
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/*
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* Copyright (C) 2009-2018 by Jonathan Naylor G4KLX
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include "Config.h"
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#include "Globals.h"
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#include "NXDNRX.h"
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#include "Utils.h"
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const q15_t SCALING_FACTOR = 18750; // Q15(0.55)
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const uint8_t MAX_FSW_BIT_ERRS = 1U;
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const uint8_t MAX_FSW_SYMBOLS_ERRS = 1U;
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const uint8_t BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
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#define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
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const uint8_t NOAVEPTR = 99U;
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const uint16_t NOENDPTR = 9999U;
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const unsigned int MAX_FSW_FRAMES = 5U + 1U;
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CNXDNRX::CNXDNRX() :
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m_state(NXDNRXS_NONE),
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m_bitBuffer(),
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m_buffer(),
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m_bitPtr(0U),
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m_dataPtr(0U),
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m_startPtr(NOENDPTR),
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m_endPtr(NOENDPTR),
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m_fswPtr(NOENDPTR),
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m_minFSWPtr(NOENDPTR),
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m_maxFSWPtr(NOENDPTR),
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m_maxCorr(0),
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m_lostCount(0U),
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m_countdown(0U),
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m_centre(),
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m_centreVal(0),
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m_threshold(),
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m_thresholdVal(0),
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m_averagePtr(NOAVEPTR),
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m_rssiAccum(0U),
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m_rssiCount(0U)
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{
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}
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void CNXDNRX::reset()
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{
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m_state = NXDNRXS_NONE;
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m_dataPtr = 0U;
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m_bitPtr = 0U;
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m_maxCorr = 0;
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m_averagePtr = NOAVEPTR;
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m_startPtr = NOENDPTR;
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m_endPtr = NOENDPTR;
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m_fswPtr = NOENDPTR;
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m_minFSWPtr = NOENDPTR;
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m_maxFSWPtr = NOENDPTR;
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m_centreVal = 0;
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m_thresholdVal = 0;
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m_lostCount = 0U;
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m_countdown = 0U;
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m_rssiAccum = 0U;
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m_rssiCount = 0U;
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}
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void CNXDNRX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length)
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{
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for (uint8_t i = 0U; i < length; i++) {
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q15_t sample = samples[i];
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m_rssiAccum += rssi[i];
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m_rssiCount++;
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m_bitBuffer[m_bitPtr] <<= 1;
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if (sample < 0)
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m_bitBuffer[m_bitPtr] |= 0x01U;
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m_buffer[m_dataPtr] = sample;
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switch (m_state) {
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case NXDNRXS_DATA:
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processData(sample);
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break;
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default:
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processNone(sample);
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break;
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}
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m_dataPtr++;
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if (m_dataPtr >= NXDN_FRAME_LENGTH_SAMPLES)
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m_dataPtr = 0U;
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m_bitPtr++;
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if (m_bitPtr >= NXDN_RADIO_SYMBOL_LENGTH)
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m_bitPtr = 0U;
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}
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}
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void CNXDNRX::processNone(q15_t sample)
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{
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bool ret = correlateFSW();
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if (ret) {
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// On the first sync, start the countdown to the state change
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if (m_countdown == 0U) {
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m_rssiAccum = 0U;
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m_rssiCount = 0U;
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io.setDecode(true);
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io.setADCDetection(true);
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m_averagePtr = NOAVEPTR;
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m_countdown = 5U;
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}
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}
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if (m_countdown > 0U)
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m_countdown--;
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if (m_countdown == 1U) {
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m_minFSWPtr = m_fswPtr + NXDN_FRAME_LENGTH_SAMPLES - 1U;
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if (m_minFSWPtr >= NXDN_FRAME_LENGTH_SAMPLES)
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m_minFSWPtr -= NXDN_FRAME_LENGTH_SAMPLES;
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m_maxFSWPtr = m_fswPtr + 1U;
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if (m_maxFSWPtr >= NXDN_FRAME_LENGTH_SAMPLES)
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m_maxFSWPtr -= NXDN_FRAME_LENGTH_SAMPLES;
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m_state = NXDNRXS_DATA;
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m_countdown = 0U;
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}
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}
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void CNXDNRX::processData(q15_t sample)
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{
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if (m_minFSWPtr < m_maxFSWPtr) {
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if (m_dataPtr >= m_minFSWPtr && m_dataPtr <= m_maxFSWPtr)
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correlateFSW();
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} else {
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if (m_dataPtr >= m_minFSWPtr || m_dataPtr <= m_maxFSWPtr)
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correlateFSW();
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}
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if (m_dataPtr == m_endPtr) {
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// Only update the centre and threshold if they are from a good sync
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if (m_lostCount == MAX_FSW_FRAMES) {
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m_minFSWPtr = m_fswPtr + NXDN_FRAME_LENGTH_SAMPLES - 1U;
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if (m_minFSWPtr >= NXDN_FRAME_LENGTH_SAMPLES)
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m_minFSWPtr -= NXDN_FRAME_LENGTH_SAMPLES;
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m_maxFSWPtr = m_fswPtr + 1U;
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if (m_maxFSWPtr >= NXDN_FRAME_LENGTH_SAMPLES)
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m_maxFSWPtr -= NXDN_FRAME_LENGTH_SAMPLES;
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}
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calculateLevels(m_startPtr, NXDN_FRAME_LENGTH_SYMBOLS);
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DEBUG4("NXDNRX: sync found pos/centre/threshold", m_fswPtr, m_centreVal, m_thresholdVal);
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uint8_t frame[NXDN_FRAME_LENGTH_BYTES + 3U];
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samplesToBits(m_startPtr, NXDN_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal);
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// We've not seen a data sync for too long, signal RXLOST and change to RX_NONE
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m_lostCount--;
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if (m_lostCount == 0U) {
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DEBUG1("NXDNRX: sync timed out, lost lock");
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io.setDecode(false);
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io.setADCDetection(false);
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serial.writeNXDNLost();
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m_state = NXDNRXS_NONE;
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m_endPtr = NOENDPTR;
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m_averagePtr = NOAVEPTR;
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m_countdown = 0U;
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m_maxCorr = 0;
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} else {
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frame[0U] = m_lostCount == (MAX_FSW_FRAMES - 1U) ? 0x01U : 0x00U;
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writeRSSIData(frame);
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m_maxCorr = 0;
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}
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}
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}
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bool CNXDNRX::correlateFSW()
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{
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if (countBits32((m_bitBuffer[m_bitPtr] & NXDN_FSW_SYMBOLS_MASK) ^ NXDN_FSW_SYMBOLS) <= MAX_FSW_SYMBOLS_ERRS) {
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uint16_t ptr = m_dataPtr + NXDN_FRAME_LENGTH_SAMPLES - NXDN_FSW_LENGTH_SAMPLES + NXDN_RADIO_SYMBOL_LENGTH;
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if (ptr >= NXDN_FRAME_LENGTH_SAMPLES)
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ptr -= NXDN_FRAME_LENGTH_SAMPLES;
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q31_t corr = 0;
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q15_t min = 16000;
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q15_t max = -16000;
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for (uint8_t i = 0U; i < NXDN_FSW_LENGTH_SYMBOLS; i++) {
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q15_t val = m_buffer[ptr];
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if (val > max)
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max = val;
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if (val < min)
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min = val;
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switch (NXDN_FSW_SYMBOLS_VALUES[i]) {
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case +3:
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corr -= (val + val + val);
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break;
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case +1:
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corr -= val;
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break;
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case -1:
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corr += val;
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break;
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default: // -3
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corr += (val + val + val);
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break;
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}
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ptr += NXDN_RADIO_SYMBOL_LENGTH;
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if (ptr >= NXDN_FRAME_LENGTH_SAMPLES)
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ptr -= NXDN_FRAME_LENGTH_SAMPLES;
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}
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if (corr > m_maxCorr) {
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if (m_averagePtr == NOAVEPTR) {
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m_centreVal = (max + min) >> 1;
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q31_t v1 = (max - m_centreVal) * SCALING_FACTOR;
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m_thresholdVal = q15_t(v1 >> 15);
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}
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uint16_t startPtr = m_dataPtr + NXDN_FRAME_LENGTH_SAMPLES - NXDN_FSW_LENGTH_SAMPLES + NXDN_RADIO_SYMBOL_LENGTH;
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if (startPtr >= NXDN_FRAME_LENGTH_SAMPLES)
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startPtr -= NXDN_FRAME_LENGTH_SAMPLES;
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uint8_t sync[NXDN_FSW_BYTES_LENGTH];
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samplesToBits(startPtr, NXDN_FSW_LENGTH_SYMBOLS, sync, 0U, m_centreVal, m_thresholdVal);
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uint8_t errs = 0U;
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for (uint8_t i = 0U; i < NXDN_FSW_BYTES_LENGTH; i++)
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errs += countBits8((sync[i] & NXDN_FSW_BYTES_MASK[i]) ^ NXDN_FSW_BYTES[i]);
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if (errs <= MAX_FSW_BIT_ERRS) {
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m_maxCorr = corr;
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m_lostCount = MAX_FSW_FRAMES;
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m_fswPtr = m_dataPtr;
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m_startPtr = startPtr;
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m_endPtr = m_dataPtr + NXDN_FRAME_LENGTH_SAMPLES - NXDN_FSW_LENGTH_SAMPLES - 1U;
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if (m_endPtr >= NXDN_FRAME_LENGTH_SAMPLES)
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m_endPtr -= NXDN_FRAME_LENGTH_SAMPLES;
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return true;
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}
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}
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}
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return false;
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}
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void CNXDNRX::calculateLevels(uint16_t start, uint16_t count)
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{
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q15_t maxPos = -16000;
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q15_t minPos = 16000;
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q15_t maxNeg = 16000;
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q15_t minNeg = -16000;
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for (uint16_t i = 0U; i < count; i++) {
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q15_t sample = m_buffer[start];
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if (sample > 0) {
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if (sample > maxPos)
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maxPos = sample;
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if (sample < minPos)
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minPos = sample;
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} else {
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if (sample < maxNeg)
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maxNeg = sample;
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if (sample > minNeg)
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minNeg = sample;
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}
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start += NXDN_RADIO_SYMBOL_LENGTH;
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if (start >= NXDN_FRAME_LENGTH_SAMPLES)
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start -= NXDN_FRAME_LENGTH_SAMPLES;
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}
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q15_t posThresh = (maxPos + minPos) >> 1;
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q15_t negThresh = (maxNeg + minNeg) >> 1;
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q15_t centre = (posThresh + negThresh) >> 1;
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q15_t threshold = posThresh - centre;
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DEBUG5("NXDNRX: pos/neg/centre/threshold", posThresh, negThresh, centre, threshold);
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if (m_averagePtr == NOAVEPTR) {
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for (uint8_t i = 0U; i < 16U; i++) {
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m_centre[i] = centre;
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m_threshold[i] = threshold;
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}
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m_averagePtr = 0U;
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} else {
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m_centre[m_averagePtr] = centre;
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m_threshold[m_averagePtr] = threshold;
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m_averagePtr++;
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if (m_averagePtr >= 16U)
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m_averagePtr = 0U;
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}
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|
||||
m_centreVal = 0;
|
||||
m_thresholdVal = 0;
|
||||
|
||||
for (uint8_t i = 0U; i < 16U; i++) {
|
||||
m_centreVal += m_centre[i];
|
||||
m_thresholdVal += m_threshold[i];
|
||||
}
|
||||
|
||||
m_centreVal >>= 4;
|
||||
m_thresholdVal >>= 4;
|
||||
}
|
||||
|
||||
void CNXDNRX::samplesToBits(uint16_t start, uint16_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold)
|
||||
{
|
||||
for (uint16_t i = 0U; i < count; i++) {
|
||||
q15_t sample = m_buffer[start] - centre;
|
||||
|
||||
if (sample < -threshold) {
|
||||
WRITE_BIT1(buffer, offset, false);
|
||||
offset++;
|
||||
WRITE_BIT1(buffer, offset, true);
|
||||
offset++;
|
||||
} else if (sample < 0) {
|
||||
WRITE_BIT1(buffer, offset, false);
|
||||
offset++;
|
||||
WRITE_BIT1(buffer, offset, false);
|
||||
offset++;
|
||||
} else if (sample < threshold) {
|
||||
WRITE_BIT1(buffer, offset, true);
|
||||
offset++;
|
||||
WRITE_BIT1(buffer, offset, false);
|
||||
offset++;
|
||||
} else {
|
||||
WRITE_BIT1(buffer, offset, true);
|
||||
offset++;
|
||||
WRITE_BIT1(buffer, offset, true);
|
||||
offset++;
|
||||
}
|
||||
|
||||
start += NXDN_RADIO_SYMBOL_LENGTH;
|
||||
if (start >= NXDN_FRAME_LENGTH_SAMPLES)
|
||||
start -= NXDN_FRAME_LENGTH_SAMPLES;
|
||||
}
|
||||
}
|
||||
|
||||
void CNXDNRX::writeRSSIData(uint8_t* data)
|
||||
{
|
||||
#if defined(SEND_RSSI_DATA)
|
||||
if (m_rssiCount > 0U) {
|
||||
uint16_t rssi = m_rssiAccum / m_rssiCount;
|
||||
|
||||
data[49U] = (rssi >> 8) & 0xFFU;
|
||||
data[50U] = (rssi >> 0) & 0xFFU;
|
||||
|
||||
serial.writeNXDNData(data, NXDN_FRAME_LENGTH_BYTES + 3U);
|
||||
} else {
|
||||
serial.writeNXDNData(data, NXDN_FRAME_LENGTH_BYTES + 1U);
|
||||
}
|
||||
#else
|
||||
serial.writeNXDNData(data, NXDN_FRAME_LENGTH_BYTES + 1U);
|
||||
#endif
|
||||
|
||||
m_rssiAccum = 0U;
|
||||
m_rssiCount = 0U;
|
||||
}
|
||||
|
||||
|
|
@ -0,0 +1,69 @@
|
|||
/*
|
||||
* Copyright (C) 2015,2016,2017,2018 by Jonathan Naylor G4KLX
|
||||
*
|
||||
* 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
|
||||
#if !defined(NXDNRX_H)
|
||||
#define NXDNRX_H
|
||||
|
||||
#include "Config.h"
|
||||
#include "NXDNDefines.h"
|
||||
|
||||
enum NXDNRX_STATE {
|
||||
NXDNRXS_NONE,
|
||||
NXDNRXS_DATA
|
||||
};
|
||||
|
||||
class CNXDNRX {
|
||||
public:
|
||||
CNXDNRX();
|
||||
|
||||
void samples(const q15_t* samples, uint16_t* rssi, uint8_t length);
|
||||
|
||||
void reset();
|
||||
|
||||
private:
|
||||
NXDNRX_STATE m_state;
|
||||
uint16_t m_bitBuffer[NXDN_RADIO_SYMBOL_LENGTH];
|
||||
q15_t m_buffer[NXDN_FRAME_LENGTH_SAMPLES];
|
||||
uint16_t m_bitPtr;
|
||||
uint16_t m_dataPtr;
|
||||
uint16_t m_startPtr;
|
||||
uint16_t m_endPtr;
|
||||
uint16_t m_fswPtr;
|
||||
uint16_t m_minFSWPtr;
|
||||
uint16_t m_maxFSWPtr;
|
||||
q31_t m_maxCorr;
|
||||
uint16_t m_lostCount;
|
||||
uint8_t m_countdown;
|
||||
q15_t m_centre[16U];
|
||||
q15_t m_centreVal;
|
||||
q15_t m_threshold[16U];
|
||||
q15_t m_thresholdVal;
|
||||
uint8_t m_averagePtr;
|
||||
uint32_t m_rssiAccum;
|
||||
uint16_t m_rssiCount;
|
||||
|
||||
void processNone(q15_t sample);
|
||||
void processData(q15_t sample);
|
||||
bool correlateFSW();
|
||||
void calculateLevels(uint16_t start, uint16_t count);
|
||||
void samplesToBits(uint16_t start, uint16_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold);
|
||||
void writeRSSIData(uint8_t* data);
|
||||
};
|
||||
|
||||
#endif
|
||||
|
||||
|
|
@ -0,0 +1,153 @@
|
|||
/*
|
||||
* Copyright (C) 2009-2018 by Jonathan Naylor G4KLX
|
||||
* Copyright (C) 2017 by Andy Uribe CA6JAU
|
||||
*
|
||||
* 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
|
||||
#include "Config.h"
|
||||
#include "Globals.h"
|
||||
#include "NXDNTX.h"
|
||||
|
||||
#include "NXDNDefines.h"
|
||||
|
||||
// Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
|
||||
static q15_t RRC_0_2_FILTER[] = {0, 0, 0, 0, 850, 219, -720, -1548, -1795, -1172, 237, 1927, 3120, 3073, 1447, -1431, -4544, -6442,
|
||||
-5735, -1633, 5651, 14822, 23810, 30367, 32767, 30367, 23810, 14822, 5651, -1633, -5735, -6442,
|
||||
-4544, -1431, 1447, 3073, 3120, 1927, 237, -1172, -1795, -1548, -720, 219, 850}; // numTaps = 45, L = 5
|
||||
const uint16_t RRC_0_2_FILTER_PHASE_LEN = 9U; // phaseLength = numTaps/L
|
||||
|
||||
const q15_t NXDN_LEVELA = 1680;
|
||||
const q15_t NXDN_LEVELB = 560;
|
||||
const q15_t NXDN_LEVELC = -560;
|
||||
const q15_t NXDN_LEVELD = -1680;
|
||||
|
||||
const uint8_t NXDN_PREAMBLE[] = {0x57U, 0x75U, 0xFDU};
|
||||
const uint8_t NXDN_SYNC = 0x5FU;
|
||||
|
||||
CNXDNTX::CNXDNTX() :
|
||||
m_buffer(1500U),
|
||||
m_modFilter(),
|
||||
m_modState(),
|
||||
m_poBuffer(),
|
||||
m_poLen(0U),
|
||||
m_poPtr(0U),
|
||||
m_txDelay(240U) // 200ms
|
||||
{
|
||||
::memset(m_modState, 0x00U, 16U * sizeof(q15_t));
|
||||
|
||||
m_modFilter.L = NXDN_RADIO_SYMBOL_LENGTH;
|
||||
m_modFilter.phaseLength = RRC_0_2_FILTER_PHASE_LEN;
|
||||
m_modFilter.pCoeffs = RRC_0_2_FILTER;
|
||||
m_modFilter.pState = m_modState;
|
||||
}
|
||||
|
||||
void CNXDNTX::process()
|
||||
{
|
||||
if (m_buffer.getData() == 0U && m_poLen == 0U)
|
||||
return;
|
||||
|
||||
if (m_poLen == 0U) {
|
||||
if (!m_tx) {
|
||||
for (uint16_t i = 0U; i < m_txDelay; i++)
|
||||
m_poBuffer[m_poLen++] = NXDN_SYNC;
|
||||
m_poBuffer[m_poLen++] = NXDN_PREAMBLE[0U];
|
||||
m_poBuffer[m_poLen++] = NXDN_PREAMBLE[1U];
|
||||
m_poBuffer[m_poLen++] = NXDN_PREAMBLE[2U];
|
||||
} else {
|
||||
for (uint8_t i = 0U; i < NXDN_FRAME_LENGTH_BYTES; i++) {
|
||||
uint8_t c = m_buffer.get();
|
||||
m_poBuffer[m_poLen++] = c;
|
||||
}
|
||||
}
|
||||
|
||||
m_poPtr = 0U;
|
||||
}
|
||||
|
||||
if (m_poLen > 0U) {
|
||||
uint16_t space = io.getSpace();
|
||||
|
||||
while (space > (4U * NXDN_RADIO_SYMBOL_LENGTH)) {
|
||||
uint8_t c = m_poBuffer[m_poPtr++];
|
||||
writeByte(c);
|
||||
|
||||
space -= 4U * NXDN_RADIO_SYMBOL_LENGTH;
|
||||
|
||||
if (m_poPtr >= m_poLen) {
|
||||
m_poPtr = 0U;
|
||||
m_poLen = 0U;
|
||||
return;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
uint8_t CNXDNTX::writeData(const uint8_t* data, uint8_t length)
|
||||
{
|
||||
if (length != (NXDN_FRAME_LENGTH_BYTES + 1U))
|
||||
return 4U;
|
||||
|
||||
uint16_t space = m_buffer.getSpace();
|
||||
if (space < NXDN_FRAME_LENGTH_BYTES)
|
||||
return 5U;
|
||||
|
||||
for (uint8_t i = 0U; i < NXDN_FRAME_LENGTH_BYTES; i++)
|
||||
m_buffer.put(data[i + 1U]);
|
||||
|
||||
return 0U;
|
||||
}
|
||||
|
||||
void CNXDNTX::writeByte(uint8_t c)
|
||||
{
|
||||
q15_t inBuffer[4U];
|
||||
q15_t outBuffer[NXDN_RADIO_SYMBOL_LENGTH * 4U];
|
||||
|
||||
const uint8_t MASK = 0xC0U;
|
||||
|
||||
for (uint8_t i = 0U; i < 4U; i++, c <<= 2) {
|
||||
switch (c & MASK) {
|
||||
case 0xC0U:
|
||||
inBuffer[i] = NXDN_LEVELA;
|
||||
break;
|
||||
case 0x80U:
|
||||
inBuffer[i] = NXDN_LEVELB;
|
||||
break;
|
||||
case 0x00U:
|
||||
inBuffer[i] = NXDN_LEVELC;
|
||||
break;
|
||||
default:
|
||||
inBuffer[i] = NXDN_LEVELD;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
::arm_fir_interpolate_q15(&m_modFilter, inBuffer, outBuffer, 4U);
|
||||
|
||||
io.write(STATE_NXDN, outBuffer, NXDN_RADIO_SYMBOL_LENGTH * 4U);
|
||||
}
|
||||
|
||||
void CNXDNTX::setTXDelay(uint8_t delay)
|
||||
{
|
||||
m_txDelay = 600U + uint16_t(delay) * 12U; // 500ms + tx delay
|
||||
|
||||
if (m_txDelay > 1200U)
|
||||
m_txDelay = 1200U;
|
||||
}
|
||||
|
||||
uint8_t CNXDNTX::getSpace() const
|
||||
{
|
||||
return m_buffer.getSpace() / YSF_FRAME_LENGTH_BYTES;
|
||||
}
|
||||
|
||||
|
|
@ -0,0 +1,51 @@
|
|||
/*
|
||||
* Copyright (C) 2015,2016,2017,2018 by Jonathan Naylor G4KLX
|
||||
*
|
||||
* 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*/
|
||||
|
||||
#if !defined(NXDNTX_H)
|
||||
#define NXDNTX_H
|
||||
|
||||
#include "Config.h"
|
||||
|
||||
#include "SerialRB.h"
|
||||
|
||||
class CNXDNTX {
|
||||
public:
|
||||
CNXDNTX();
|
||||
|
||||
uint8_t writeData(const uint8_t* data, uint8_t length);
|
||||
|
||||
void process();
|
||||
|
||||
void setTXDelay(uint8_t delay);
|
||||
|
||||
uint8_t getSpace() const;
|
||||
|
||||
private:
|
||||
CSerialRB m_buffer;
|
||||
arm_fir_interpolate_instance_q15 m_modFilter;
|
||||
q15_t m_modState[16U]; // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
|
||||
uint8_t m_poBuffer[1200U];
|
||||
uint16_t m_poLen;
|
||||
uint16_t m_poPtr;
|
||||
uint16_t m_txDelay;
|
||||
|
||||
void writeByte(uint8_t c);
|
||||
};
|
||||
|
||||
#endif
|
||||
|
||||
Loading…
Reference in New Issue