sp5wwp

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <math.h>
#include <sys/ioctl.h>
#include <linux/spi/spidev.h>

sp5wwp

/*
to pass IQ baseband samples to SX1255 over I2S, run this:
./zmq-sub | aplay -t raw -f S32_LE -r 192000 -c 2 --device="hw:0,0"

note: you need to enable I2S overlay (acting as a slave)
this one works good: https://github.com/AkiyukiOkayasu/RaspberryPi_I2S_Slave
note: setting the rate to 192k isn't really effective, the actual rate is 125k (governed by the I2S master - SX1255)
*/

#include <stdio.h>

sp5wwp

/*
to source IQ baseband samples from SX1255 over I2S, run this:
arecord -t raw -f S32_LE -r 192000 -c 2 --device="hw:0,1" | ./zmq-pub

note: you need to enable I2S overlay (acting as a slave)
this one works good: https://github.com/AkiyukiOkayasu/RaspberryPi_I2S_Slave
note: setting the rate to 192k isn't really effective, the actual rate is 125k (governed by the I2S master - SX1255)
*/

#include <stdio.h>

sp5wwp

for(uint8_t y = startRow; y < endRow; y++)
{
  for(uint8_t x = 0; x < SCREEN_WIDTH; x++)
  {
    if(y<SCREEN_HEIGHT/2)
    {
      size_t pos1 = x + y * SCREEN_WIDTH;
      size_t pos2 = x + (SCREEN_HEIGHT-1-y) * SCREEN_WIDTH;
      uint16_t tmp = frameBuffer[pos1];
      frameBuffer[pos1] = __builtin_bswap16(frameBuffer[pos2]);

sp5wwp

void AT86_Write(const uint16_t addr, const uint8_t val)
{
	uint8_t tx[3]={(addr>>8)|(1<<7), addr&0xFF, val}; //write enable

	GPIOA->BSRR=(1<<(4+16));
	HAL_SPI_Transmit(&hspi1, tx, 3, 1);
	GPIOA->BSRR=(1<<4);
	HAL_Delay(2);
}

sp5wwp

#!/bin/bash

if [ "$#" -lt 1 ]; then
    echo "Not enough parameters."
	exit
fi

mkdir $1
cd $1

sp5wwp

delay_ms(250);
WM8960_Write(0x0F, 0x1FF); delay_ms(250); //reset

WM8960_Write(0x34, 0x018); //PLL prescale=2

WM8960_Write(0x04, 0x3B1); //clocking

//WM8960_Write(0x07, (1<<1)); //16-bit, I2S format
WM8960_Write(0x07, (1<<0)); //16-bit, left justified MSB first format

sp5wwp

--I2S sample source - 1kHz sinewave
--8kHz, 16-bit, left-aligned, MSB first
--clk     - 12MHz input clock
--i2s_clk - 400kHz main clock
--lr_clk  - 8kHz channel clock
--outp    - data output

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_arith.all;

sp5wwp

/*
 * M17 baseband interpolator
 *
 * Wojciech Kaczmarski SP5WWP
 * M17 Project, Nov 2022
 */

#include <stdio.h>
#include <stdint.h>
#include <unistd.h>

sp5wwp

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% root-Nyquist (M) filter design                        %
% Source:                                               %
% https://my.ece.utah.edu/~farhang/Nyquist_M_r1.pdf     %
% Edited by Wojciech SP5WWP to work with rcosdesign()   %
%                                                       %
% parameters:                                           %
% N: filter order (filter length = N+1)                 %
% M: number of samples per symbol period                %
% alpha: rolloff factor (range 0 to 1)                  %