M17_Implementations/SP5WWP/lib/lib.c

68 wiersze
1.6 KiB
C

//--------------------------------------------------------------------
// M17 C library - lib.c
//
// Wojciech Kaczmarski, SP5WWP
// M17 Project, 29 December 2023
//--------------------------------------------------------------------
#include <stdio.h>
#include <encode/symbols.h>
#include "lib.h"
//misc
void send_preamble(const uint8_t type)
{
float symb;
if(type) //pre-BERT
{
for(uint16_t i=0; i<192/2; i++) //40ms * 4800 = 192
{
symb=-3.0;
fwrite((uint8_t*)&symb, sizeof(float), 1, stdout);
symb=+3.0;
fwrite((uint8_t*)&symb, sizeof(float), 1, stdout);
}
}
else //pre-LSF
{
for(uint16_t i=0; i<192/2; i++) //40ms * 4800 = 192
{
symb=+3.0;
fwrite((uint8_t*)&symb, sizeof(float), 1, stdout);
symb=-3.0;
fwrite((uint8_t*)&symb, sizeof(float), 1, stdout);
}
}
}
void send_syncword(const uint16_t syncword)
{
float symb;
for(uint8_t i=0; i<16; i+=2)
{
symb=symbol_map[(syncword>>(14-i))&3];
fwrite((uint8_t*)&symb, sizeof(float), 1, stdout);
}
}
//send the data (can be used for both LSF and frames)
void send_data(const uint8_t* in)
{
float s=0.0;
for(uint16_t i=0; i<SYM_PER_PLD; i++) //40ms * 4800 - 8 (syncword)
{
s=symbol_map[in[2*i]*2+in[2*i+1]];
fwrite((uint8_t*)&s, sizeof(float), 1, stdout);
}
}
void send_eot(void)
{
float symb=+3.0;
for(uint16_t i=0; i<192; i++) //40ms * 4800 = 192
{
fwrite((uint8_t*)&symb, sizeof(float), 1, stdout);
}
}