/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
* Copyright (C) 2016 Furrtek
*
* This file is part of PortaPack.
*
* 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, 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; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "rds.hpp"
#include "portapack_shared_memory.hpp"
// RDS infos:
// One group = 4 blocks = 4 * 26 bits
// One block = 26 bits (16 bits data + 10 bits checkword)
// Sent MSB first
namespace rds {
uint32_t makeblock(uint32_t data, uint16_t offset) {
uint16_t CRC = 0;
uint8_t bit;
for (uint8_t i = 0; i < 16; i++) {
bit = (((data << i) & 0x8000) >> 15) ^ (CRC >> 9);
if (bit) CRC ^= 0b0011011100;
CRC = ((CRC << 1) | bit) & 0x3FF;
}
return (data << 10) | (CRC ^ offset);
}
// Todo:
// Make PI
// TA/TP flags
// Group selection
// Boolean to binary
uint8_t b2b(const bool in) {
if (in)
return 1;
else
return 0;
}
// Type 0B groups are like 0A groups but without alternative frequency data
void make_0B_group(uint32_t blocks[], const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool TA,
const bool MS, const bool DI, const uint8_t C, const char * chars) {
blocks[0] = PI_code;
blocks[1] = (0x0 << 12) | (1 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | (b2b(TA) << 4) | (b2b(MS) << 3) | (b2b(DI) << 2) | (C & 3);
blocks[2] = PI_code;
blocks[3] = (chars[0] << 8) | chars[1];
}
// For RadioText, up to 64 chars with 2A, 32 chars with 2B
void make_2A_group(uint32_t blocks[], const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool AB,
const uint8_t segment, const char * chars) {
blocks[0] = PI_code;
blocks[1] = (0x2 << 12) | (0 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | (b2b(AB) << 4) | (segment & 15);
blocks[2] = (chars[0] << 8) | chars[1];
blocks[3] = (chars[2] << 8) | chars[3];
}
// Time and date - usually one message per minute - Month: 1~12 - Day: 1~31 - Hour/Minute: 0~59 - Local offset: -12/+12 from UTC
void make_4A_group(uint32_t blocks[], const uint16_t PI_code, const bool TP, const uint8_t PTY,
const uint16_t year, const uint8_t month, const uint8_t day,
const uint8_t hour, const uint8_t minute, const int8_t local_offset) {
uint32_t L = 0;
uint32_t day_code;
if ((month == 1) || (month == 2)) L = 1;
day_code = 14956 + day + (uint32_t)((float)(year - 1900 - L) * 365.25) + uint16_t((float)((month + 1) + L * 12) * 30.6001);
blocks[0] = PI_code;
blocks[1] = (0x4 << 12) | (0 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | ((day_code & 0x18000) >> 15);
blocks[2] = ((day_code & 0x7FFF) << 1) | (hour >> 4);
blocks[3] = ((hour & 15) << 12) | ((minute & 0x3F) << 6) | (local_offset & 0x3F);
}
uint16_t gen_PSN(const char * psname, const RDS_flags * rds_flags) {
uint8_t c;
uint32_t group[4][4] = { 0 };
// 4 groups with 2 PSN characters in each
for (c = 0; c < 4; c++)
make_0B_group(&group[c][0], rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, rds_flags->TA, rds_flags->MS, rds_flags->DI, c, &psname[c * 2]);
// Generate checkbits for each block of each group
for (c = 0; c < 4; c++) {
group[c][0] = makeblock(group[c][0], RDS_OFFSET_A);
group[c][1] = makeblock(group[c][1], RDS_OFFSET_B);
group[c][2] = makeblock(group[c][2], RDS_OFFSET_Cp); // C' !
group[c][3] = makeblock(group[c][3], RDS_OFFSET_D);
}
uint32_t * tx_data_u32 = (uint32_t*)shared_memory.bb_data.data;
// Copy to tx_data for baseband
for (c = 0; c < 4 * 4; c++)
tx_data_u32[c] = group[c >> 2][c & 3];
return 4 * 4 * 26;
}
uint16_t gen_RadioText(const char * text, const bool AB, const RDS_flags * rds_flags) {
size_t c, i;
uint32_t * group;
char radiotext_buffer[65] = { 0 };
uint8_t rtlen, groups;
strncpy(radiotext_buffer, text, 64);
rtlen = strlen(radiotext_buffer);
// Pad message with spaces to a multiple of 4 characters
while (rtlen & 3)
radiotext_buffer[rtlen++] = ' ';
// End message with Carriage Return, as required
if (rtlen < 64) radiotext_buffer[rtlen] = 0x0D;
groups = rtlen >> 2; // 4 characters per group
group = (uint32_t*)chHeapAlloc(0, 4 * groups * sizeof(uint32_t));
for (c = 0; c < groups; c++)
make_2A_group(&group[c * 4], rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, AB, c, &radiotext_buffer[c * 4]);
// Generate checkbits for each block of each group
for (c = 0; c < groups; c++) {
i = c * 4;
group[i + 0] = makeblock(group[i + 0], RDS_OFFSET_A);
group[i + 1] = makeblock(group[i + 1], RDS_OFFSET_B);
group[i + 2] = makeblock(group[i + 2], RDS_OFFSET_C);
group[i + 3] = makeblock(group[i + 3], RDS_OFFSET_D);
}
uint32_t * tx_data_u32 = (uint32_t*)shared_memory.bb_data.data;
// Copy to tx_data for baseband
for (c = 0; c < (groups * 4); c++)
tx_data_u32[c] = group[c];
chHeapFree(group);
return groups * 4 * 26;
}
uint16_t gen_ClockTime(const RDS_flags * rds_flags,
const uint16_t year, const uint8_t month, const uint8_t day,
const uint8_t hour, const uint8_t minute, const int8_t local_offset) {
uint8_t c;
uint32_t group[4] = { 0 };
make_4A_group(&group[0], rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, year, month, day, hour, minute, local_offset);
// Generate checkbits for each block
group[0] = makeblock(group[0], RDS_OFFSET_A);
group[1] = makeblock(group[1], RDS_OFFSET_B);
group[2] = makeblock(group[2], RDS_OFFSET_C);
group[3] = makeblock(group[3], RDS_OFFSET_D);
uint32_t * tx_data_u32 = (uint32_t*)shared_memory.bb_data.data;
// Copy to tx_data for baseband
for (c = 0; c < 4; c++)
tx_data_u32[c] = group[c];
return 4 * 26;
}
} /* namespace rds */