mirror of
https://github.com/g4klx/MMDVM.git
synced 2026-02-15 12:14:19 +01:00
694b83123a
In to NXDN possible problem on sinc filter anc isinc filter, think they must be recalculated but do not know how to do it. On D-STAR, DMR, C4FM and P25 it work.
403 lines
12 KiB
C++
403 lines
12 KiB
C++
/*
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* Copyright (C) 2009-2017 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 "DMRSlotRX.h"
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#include "DMRSlotType.h"
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#include "Utils.h"
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const uint16_t SCAN_START = 790U;
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const uint16_t SCAN_END = 920U;
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const q15_t SCALING_FACTOR = 19505; // Q15(0.60)
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const uint8_t MAX_SYNC_SYMBOLS_ERRS = 4U;
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const uint8_t MAX_SYNC_BYTES_ERRS = 6U;
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const uint8_t MAX_SYNC_LOST_FRAMES = 26U;
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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 uint16_t NOENDPTR = 9999U;
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const uint8_t CONTROL_NONE = 0x00U;
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const uint8_t CONTROL_VOICE = 0x20U;
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const uint8_t CONTROL_DATA = 0x40U;
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CDMRSlotRX::CDMRSlotRX(bool slot) :
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m_slot(slot),
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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_syncPtr(0U),
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m_startPtr(0U),
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m_endPtr(NOENDPTR),
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m_delayPtr(0U),
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m_maxCorr(0),
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m_centre(),
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m_threshold(),
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m_averagePtr(0U),
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m_control(CONTROL_NONE),
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m_syncCount(0U),
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m_colorCode(0U),
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m_delay(0U),
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m_state(DMRRXS_NONE),
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m_n(0U),
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m_type(0U),
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m_rssi()
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{
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}
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void CDMRSlotRX::start()
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{
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m_dataPtr = 0U;
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m_delayPtr = 0U;
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m_bitPtr = 0U;
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m_maxCorr = 0;
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m_control = CONTROL_NONE;
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}
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void CDMRSlotRX::reset()
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{
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m_syncPtr = 0U;
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m_dataPtr = 0U;
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m_delayPtr = 0U;
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m_bitPtr = 0U;
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m_maxCorr = 0;
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m_control = CONTROL_NONE;
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m_syncCount = 0U;
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m_state = DMRRXS_NONE;
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m_startPtr = 0U;
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m_endPtr = NOENDPTR;
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}
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bool CDMRSlotRX::processSample(q15_t sample, uint16_t rssi)
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{
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m_delayPtr++;
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if (m_delayPtr < m_delay)
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return m_state != DMRRXS_NONE;
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// Ensure that the buffer doesn't overflow
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if (m_dataPtr > m_endPtr || m_dataPtr >= 1900U)
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return m_state != DMRRXS_NONE;
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m_buffer[m_dataPtr] = sample;
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m_rssi[m_dataPtr] = rssi;
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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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if (m_state == DMRRXS_NONE) {
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if (m_dataPtr >= SCAN_START && m_dataPtr <= SCAN_END)
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correlateSync(true);
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} else {
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uint16_t min = m_syncPtr - 1U;
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uint16_t max = m_syncPtr + 1U;
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if (m_dataPtr >= min && m_dataPtr <= max)
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correlateSync(false);
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}
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if (m_dataPtr == m_endPtr) {
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// Find the average centre and threshold values
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q15_t centre = (m_centre[0U] + m_centre[1U] + m_centre[2U] + m_centre[3U]) >> 2;
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q15_t threshold = (m_threshold[0U] + m_threshold[1U] + m_threshold[2U] + m_threshold[3U]) >> 2;
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uint8_t frame[DMR_FRAME_LENGTH_BYTES + 3U];
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frame[0U] = m_control;
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uint16_t ptr = m_endPtr - DMR_FRAME_LENGTH_SAMPLES + DMR_RADIO_SYMBOL_LENGTH + 1U;
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samplesToBits(ptr, DMR_FRAME_LENGTH_SYMBOLS, frame, 8U, centre, threshold);
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if (m_control == CONTROL_DATA) {
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// Data sync
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uint8_t colorCode;
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uint8_t dataType;
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CDMRSlotType slotType;
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slotType.decode(frame + 1U, colorCode, dataType);
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if (colorCode == m_colorCode) {
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m_syncCount = 0U;
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m_n = 0U;
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frame[0U] |= dataType;
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switch (dataType) {
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case DT_DATA_HEADER:
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DEBUG5("DMRSlotRX: data header found slot/pos/centre/threshold", m_slot ? 2U : 1U, m_syncPtr, centre, threshold);
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writeRSSIData(frame);
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m_state = DMRRXS_DATA;
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m_type = 0x00U;
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break;
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case DT_RATE_12_DATA:
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case DT_RATE_34_DATA:
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case DT_RATE_1_DATA:
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if (m_state == DMRRXS_DATA) {
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DEBUG5("DMRSlotRX: data payload found slot/pos/centre/threshold", m_slot ? 2U : 1U, m_syncPtr, centre, threshold);
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writeRSSIData(frame);
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m_type = dataType;
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}
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break;
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case DT_VOICE_LC_HEADER:
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DEBUG5("DMRSlotRX: voice header found slot/pos/centre/threshold", m_slot ? 2U : 1U, m_syncPtr, centre, threshold);
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writeRSSIData(frame);
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m_state = DMRRXS_VOICE;
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break;
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case DT_VOICE_PI_HEADER:
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if (m_state == DMRRXS_VOICE) {
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DEBUG5("DMRSlotRX: voice pi header found slot/pos/centre/threshold", m_slot ? 2U : 1U, m_syncPtr, centre, threshold);
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writeRSSIData(frame);
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}
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m_state = DMRRXS_VOICE;
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break;
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case DT_TERMINATOR_WITH_LC:
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if (m_state == DMRRXS_VOICE) {
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DEBUG5("DMRSlotRX: voice terminator found slot/pos/centre/threshold", m_slot ? 2U : 1U, m_syncPtr, centre, threshold);
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writeRSSIData(frame);
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m_state = DMRRXS_NONE;
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m_endPtr = NOENDPTR;
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}
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break;
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default: // DT_CSBK
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DEBUG5("DMRSlotRX: csbk found slot/pos/centre/threshold", m_slot ? 2U : 1U, m_syncPtr, centre, threshold);
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writeRSSIData(frame);
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m_state = DMRRXS_NONE;
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m_endPtr = NOENDPTR;
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break;
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}
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}
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} else if (m_control == CONTROL_VOICE) {
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// Voice sync
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DEBUG5("DMRSlotRX: voice sync found slot/pos/centre/threshold", m_slot ? 2U : 1U, m_syncPtr, centre, threshold);
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writeRSSIData(frame);
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m_state = DMRRXS_VOICE;
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m_syncCount = 0U;
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m_n = 0U;
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} else {
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if (m_state != DMRRXS_NONE) {
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m_syncCount++;
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if (m_syncCount >= MAX_SYNC_LOST_FRAMES) {
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serial.writeDMRLost(m_slot);
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m_state = DMRRXS_NONE;
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m_endPtr = NOENDPTR;
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}
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}
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if (m_state == DMRRXS_VOICE) {
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if (m_n >= 5U) {
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frame[0U] = CONTROL_VOICE;
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m_n = 0U;
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} else {
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frame[0U] = ++m_n;
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}
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serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
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} else if (m_state == DMRRXS_DATA) {
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if (m_type != 0x00U) {
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frame[0U] = CONTROL_DATA | m_type;
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writeRSSIData(frame);
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}
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}
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}
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}
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m_dataPtr++;
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m_bitPtr++;
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if (m_bitPtr >= DMR_RADIO_SYMBOL_LENGTH)
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m_bitPtr = 0U;
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return m_state != DMRRXS_NONE;
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}
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void CDMRSlotRX::correlateSync(bool first)
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{
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uint8_t errs = countBits32((m_bitBuffer[m_bitPtr] & DMR_SYNC_SYMBOLS_MASK) ^ DMR_MS_DATA_SYNC_SYMBOLS);
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// The voice sync is the complement of the data sync
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bool data = (errs <= MAX_SYNC_SYMBOLS_ERRS);
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bool voice = (errs >= (DMR_SYNC_LENGTH_SYMBOLS - MAX_SYNC_SYMBOLS_ERRS));
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if (data || voice) {
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uint16_t ptr = m_dataPtr - DMR_SYNC_LENGTH_SAMPLES + DMR_RADIO_SYMBOL_LENGTH;
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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 < DMR_SYNC_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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int8_t corrVal;
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if (data)
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corrVal = DMR_MS_DATA_SYNC_SYMBOLS_VALUES[i];
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else
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corrVal = DMR_MS_VOICE_SYNC_SYMBOLS_VALUES[i];
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switch (corrVal) {
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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 += DMR_RADIO_SYMBOL_LENGTH;
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}
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if (corr > m_maxCorr) {
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q15_t centre = (max + min) >> 1;
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q31_t v1 = (max - centre) * SCALING_FACTOR;
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q15_t threshold = q15_t(v1 >> 15);
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uint8_t sync[DMR_SYNC_BYTES_LENGTH];
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uint16_t ptr = m_dataPtr - DMR_SYNC_LENGTH_SAMPLES + DMR_RADIO_SYMBOL_LENGTH;
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samplesToBits(ptr, DMR_SYNC_LENGTH_SYMBOLS, sync, 4U, centre, threshold);
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if (data) {
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uint8_t errs = 0U;
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for (uint8_t i = 0U; i < DMR_SYNC_BYTES_LENGTH; i++)
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errs += countBits8((sync[i] & DMR_SYNC_BYTES_MASK[i]) ^ DMR_MS_DATA_SYNC_BYTES[i]);
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if (errs <= MAX_SYNC_BYTES_ERRS) {
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if (first) {
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m_threshold[0U] = m_threshold[1U] = m_threshold[2U] = m_threshold[3U] = threshold;
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m_centre[0U] = m_centre[1U] = m_centre[2U] = m_centre[3U] = centre;
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m_averagePtr = 0U;
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} else {
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m_threshold[m_averagePtr] = threshold;
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m_centre[m_averagePtr] = centre;
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m_averagePtr++;
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if (m_averagePtr >= 4U)
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m_averagePtr = 0U;
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}
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m_maxCorr = corr;
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m_control = CONTROL_DATA;
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m_syncPtr = m_dataPtr;
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m_startPtr = m_dataPtr - DMR_SLOT_TYPE_LENGTH_SAMPLES / 2U - DMR_INFO_LENGTH_SAMPLES / 2U - DMR_SYNC_LENGTH_SAMPLES;
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m_endPtr = m_dataPtr + DMR_SLOT_TYPE_LENGTH_SAMPLES / 2U + DMR_INFO_LENGTH_SAMPLES / 2U - 1U;
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}
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} else { // if (voice)
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uint8_t errs = 0U;
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for (uint8_t i = 0U; i < DMR_SYNC_BYTES_LENGTH; i++)
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errs += countBits8((sync[i] & DMR_SYNC_BYTES_MASK[i]) ^ DMR_MS_VOICE_SYNC_BYTES[i]);
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if (errs <= MAX_SYNC_BYTES_ERRS) {
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if (first) {
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m_threshold[0U] = m_threshold[1U] = m_threshold[2U] = m_threshold[3U] = threshold;
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m_centre[0U] = m_centre[1U] = m_centre[2U] = m_centre[3U] = centre;
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m_averagePtr = 0U;
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} else {
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m_threshold[m_averagePtr] = threshold;
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m_centre[m_averagePtr] = centre;
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m_averagePtr++;
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if (m_averagePtr >= 4U)
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m_averagePtr = 0U;
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}
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m_maxCorr = corr;
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m_control = CONTROL_VOICE;
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m_syncPtr = m_dataPtr;
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m_startPtr = m_dataPtr - DMR_SLOT_TYPE_LENGTH_SAMPLES / 2U - DMR_INFO_LENGTH_SAMPLES / 2U - DMR_SYNC_LENGTH_SAMPLES;
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m_endPtr = m_dataPtr + DMR_SLOT_TYPE_LENGTH_SAMPLES / 2U + DMR_INFO_LENGTH_SAMPLES / 2U - 1U;
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}
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}
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}
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}
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}
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void CDMRSlotRX::samplesToBits(uint16_t start, uint8_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold)
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{
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for (uint8_t i = 0U; i < count; i++, start += DMR_RADIO_SYMBOL_LENGTH) {
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q15_t sample = m_buffer[start] - centre;
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if (sample < -threshold) {
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WRITE_BIT1(buffer, offset, false);
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offset++;
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WRITE_BIT1(buffer, offset, true);
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offset++;
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} else if (sample < 0) {
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WRITE_BIT1(buffer, offset, false);
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offset++;
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WRITE_BIT1(buffer, offset, false);
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offset++;
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} else if (sample < threshold) {
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WRITE_BIT1(buffer, offset, true);
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offset++;
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WRITE_BIT1(buffer, offset, false);
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offset++;
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} else {
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WRITE_BIT1(buffer, offset, true);
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offset++;
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WRITE_BIT1(buffer, offset, true);
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offset++;
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}
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}
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}
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void CDMRSlotRX::setColorCode(uint8_t colorCode)
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{
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m_colorCode = colorCode;
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}
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void CDMRSlotRX::setDelay(uint8_t delay)
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{
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m_delay = delay;
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}
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void CDMRSlotRX::writeRSSIData(uint8_t* frame)
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{
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#if defined(SEND_RSSI_DATA)
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// Calculate RSSI average over a burst period. We don't take into account 2.5 ms at the beginning and 2.5 ms at the end
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uint16_t start = m_startPtr + DMR_SYNC_LENGTH_SAMPLES / 2U;
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uint32_t accum = 0U;
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for (uint16_t i = 0U; i < (DMR_FRAME_LENGTH_SAMPLES - DMR_SYNC_LENGTH_SAMPLES); i++)
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accum += m_rssi[start++];
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uint16_t avg = accum / (DMR_FRAME_LENGTH_SAMPLES - DMR_SYNC_LENGTH_SAMPLES);
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frame[34U] = (avg >> 8) & 0xFFU;
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frame[35U] = (avg >> 0) & 0xFFU;
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serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 3U);
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#else
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serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
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#endif
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}
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