MMDVM/CalDStarRX.cpp

129 lines
3.1 KiB
C++

/*
* Copyright (C) 2009-2016 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.
*/
#include "Config.h"
#include "Globals.h"
#include "CalDStarRX.h"
#include "Utils.h"
const unsigned int BUFFER_LENGTH = 200U;
const uint32_t PLLMAX = 0x10000U;
const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_BIT_LENGTH;
const uint32_t INC = PLLINC / 32U;
// D-Star bit order version of 0x55 0x2D 0x16
const uint32_t DATA_SYNC_DATA1 = 0x00AAB468U;
const uint32_t DATA_SYNC_DATA2 = 0x00554B97U;
const uint32_t DATA_SYNC_MASK = 0x00FFFFFFU;
const uint8_t DATA_SYNC_ERRS = 2U;
CCalDStarRX::CCalDStarRX() :
m_pll(0U),
m_prev(false),
m_patternBuffer(0x00U),
m_rxBuffer(),
m_ptr(0U)
{
}
void CCalDStarRX::samples(const q15_t* samples, uint8_t length)
{
for (uint16_t i = 0U; i < length; i++) {
bool bit = samples[i] < 0;
if (bit != m_prev) {
if (m_pll < (PLLMAX / 2U))
m_pll += INC;
else
m_pll -= INC;
}
m_prev = bit;
m_pll += PLLINC;
if (m_pll >= PLLMAX) {
m_pll -= PLLMAX;
process(samples[i]);
}
}
}
void CCalDStarRX::process(q15_t value)
{
m_patternBuffer <<= 1;
if (value < 0)
m_patternBuffer |= 0x01U;
m_rxBuffer[m_ptr++] = value;
if (m_ptr >= 24U)
m_ptr = 0U;
if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA1) <= DATA_SYNC_ERRS) {
q15_t max = -16000;
q15_t min = 16000;
for (uint8_t i = 0U; i < 24U; i++) {
q15_t value = m_rxBuffer[i];
if (value > max)
max = value;
if (value < min)
min = value;
}
if ((max - min) > 5) {
uint8_t buffer[5U];
buffer[0U] = 0x00U;
buffer[1U] = (max >> 8) & 0xFFU;
buffer[2U] = (max >> 0) & 0xFFU;
buffer[3U] = (min >> 8) & 0xFFU;
buffer[4U] = (min >> 0) & 0xFFU;
serial.writeCalData(buffer, 5U);
}
}
if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA2) <= DATA_SYNC_ERRS) {
q15_t max = -16000;
q15_t min = 16000;
for (uint8_t i = 0U; i < 24U; i++) {
q15_t value = m_rxBuffer[i];
if (value > max)
max = value;
if (value < min)
min = value;
}
if ((max - min) > 5) {
uint8_t buffer[5U];
buffer[0U] = 0x80U;
buffer[1U] = (max >> 8) & 0xFFU;
buffer[2U] = (max >> 0) & 0xFFU;
buffer[3U] = (min >> 8) & 0xFFU;
buffer[4U] = (min >> 0) & 0xFFU;
serial.writeCalData(buffer, 5U);
}
}
}