mirror of https://github.com/markqvist/MMDVM.git
151 lines
3.9 KiB
C++
151 lines
3.9 KiB
C++
/*
|
|
* 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 = 1893;
|
|
const q15_t NXDN_LEVELB = 631;
|
|
const q15_t NXDN_LEVELC = -631;
|
|
const q15_t NXDN_LEVELD = -1893;
|
|
|
|
const uint8_t NXDN_START_SYNC = 0x77U;
|
|
const uint8_t NXDN_END_SYNC = 0xFFU;
|
|
|
|
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_START_SYNC;
|
|
} 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;
|
|
}
|
|
|