Airband VOR receiver and trasmitter (#3244)

* First test

* Reorder includes for consistency and fix string dereference in VorCdiIndicator

* Add memory section and linker script entry for vor_rx application

* Testing VOR TX

* Moving VOR TX to SD

* Code refactoring to align with guidelines

* Add TODO comment to verify radial sign convention in vor_tx_config

* Remove unnecessary set_dirty() calls in VorRxView methods

* Update Course Deviation Indicator label and adjust UI element positions

* Update VorTxView to run prepared image from memory map

* Update build condition in nightly release workflow to include workflow_dispatch event

* Reverting action changes

* Adjust Course Deviation Indicator layout and refine painting logic

* Refactor VorRxView UI elements for improved layout and clarity

* Add calibration field and update radial calculation logic in VorRxView

* Enhance VOR processing: add renormalization to phase oscillator, improve signal handling, and update configuration parameters

* Implement radial smoothing and TO/FROM state handling in VorRxView; update VOR processing logic

* Setting comments inline

* Refactor VorCdiIndicator and VorRxView: change normalize_signed_degrees to use int32_t, update radial smoothing to use fixed point arithmetic to reduce flash usage

* Update external app address end to 0xAE0B0000

* Update set_vor_tx_config to include enabled parameter for consistency

* Refactor VorRx to omit decim_2 stage and update comments for clarity on VOR processing

* Add RSSI, Channel, and Audio fields to VorRxView to mimic existing apps

* Refactor VorRxView labels and status messages

* Update VorRxView calibration field range to allow full circle input

* Completing Ident transmission logic

* Fixing TX gain and moving log label

* Refactor VOR phase calculations and update radial offset handling for accurate bearing representation

* Add low-pass filters to strip 9960 Hz subcarrier from audio output
This commit is contained in:
Luca
2026-07-04 08:49:21 +02:00
committed by GitHub
parent 7481aefe9f
commit b5d84fcc4d
20 changed files with 1765 additions and 1 deletions
+1
View File
@@ -83,3 +83,4 @@ venv/
# generated bitmap arr file
# TODO: generate bitmap during build, since we use python during build anyway, lemme know if this is a bad idea @zxkmm
/firmware/tools/bitmap.hpp
tmp/*
+10
View File
@@ -361,6 +361,16 @@ void set_noaaapt_config() {
send_message(&message);
}
void set_vor_config(bool enabled) {
const VorRxConfigureMessage message{enabled};
send_message(&message);
}
void set_vor_tx_config(uint16_t radial_deg, bool ident_enabled, const std::string& ident, bool enabled) {
const VorTxConfigureMessage message{radial_deg, ident_enabled, ident.c_str(), enabled};
send_message(&message);
}
void set_flex_config() {
const FlexConfigureMessage message{};
send_message(&message);
+2
View File
@@ -113,6 +113,8 @@ void set_morsetx_config(uint8_t mode, uint32_t tone, float fm_delta);
void set_morsetx_key(bool key_down);
void set_wefax_config(uint8_t lpm, uint8_t ioc);
void set_noaaapt_config();
void set_vor_config(bool enabled = true);
void set_vor_tx_config(uint16_t radial_deg, bool ident_enabled = true, const std::string& ident = "", bool enabled = true);
void set_flex_config();
void set_bitstream_config(uint32_t deviation, uint8_t mode); // mode 0 for am, 1 for 2fsk
void set_rtty_config(uint16_t baud, uint16_t shift, uint8_t* payload = nullptr, uint16_t payload_length = 0); // baud*100
+10
View File
@@ -133,6 +133,14 @@ set(EXTCPPSRC
external/noaaapt_rx/main.cpp
external/noaaapt_rx/ui_noaaapt_rx.cpp
#vor_rx
external/vor_rx/main.cpp
external/vor_rx/ui_vor_rx.cpp
#vor_tx
external/vor_tx/main.cpp
external/vor_tx/ui_vor_tx.cpp
#shoppingcart_lock 272 bytes
external/shoppingcart_lock/main.cpp
external/shoppingcart_lock/shoppingcart_lock.cpp
@@ -401,6 +409,8 @@ set(EXTAPPLIST
acars_rx
wefax_rx
noaaapt_rx
vor_rx
vor_tx
shoppingcart_lock
ookbrute
ook_editor
+14
View File
@@ -111,6 +111,8 @@ MEMORY
ram_external_app_flex_tx (rwx) : org = 0xAE060000, len = 32k
ram_external_app_hard_reset (rwx) : org = 0xAE070000, len = 32k
ram_external_app_secplustx (rwx) : org = 0xAE080000, len = 32k
ram_external_app_vor_rx (rwx) : org = 0xAE090000, len = 32k
ram_external_app_vor_tx (rwx) : org = 0xAE0A0000, len = 32k
}
SECTIONS
@@ -391,6 +393,18 @@ SECTIONS
*(*ui*external_app*noaaapt_rx*);
} > ram_external_app_noaaapt_rx
.external_app_vor_rx : ALIGN(4) SUBALIGN(4)
{
KEEP(*(.external_app.app_vor_rx.application_information));
*(*ui*external_app*vor_rx*);
} > ram_external_app_vor_rx
.external_app_vor_tx : ALIGN(4) SUBALIGN(4)
{
KEEP(*(.external_app.app_vor_tx.application_information));
*(*ui*external_app*vor_tx*);
} > ram_external_app_vor_tx
.external_app_breakout : ALIGN(4) SUBALIGN(4)
{
KEEP(*(.external_app.app_breakout.application_information));
+85
View File
@@ -0,0 +1,85 @@
/*
* Copyright (C) 2026 PortaPack Mayhem
*
* 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; if not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "ui.hpp"
#include "ui_vor_rx.hpp"
#include "ui_navigation.hpp"
#include "external_app.hpp"
namespace ui::external_app::vor_rx {
void initialize_app(ui::NavigationView& nav) {
nav.push<VorRxView>();
}
} // namespace ui::external_app::vor_rx
extern "C" {
__attribute__((section(".external_app.app_vor_rx.application_information"), used)) application_information_t _application_information_vor_rx = {
/*.memory_location = */ (uint8_t*)0x00000000,
/*.externalAppEntry = */ ui::external_app::vor_rx::initialize_app,
/*.header_version = */ CURRENT_HEADER_VERSION,
/*.app_version = */ VERSION_MD5,
/*.app_name = */ "VOR RX",
/*.bitmap_data = */ {
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x80,
0x01,
0xC0,
0x03,
0xE0,
0x07,
0xF0,
0x0F,
0xF8,
0x1F,
0xF8,
0x1F,
0xF0,
0x0F,
0xE0,
0x07,
0xC0,
0x03,
0x80,
0x01,
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
},
/*.icon_color = */ ui::Color::orange().v,
/*.menu_location = */ app_location_t::RX,
/*.desired_menu_position = */ -1,
/*.m4_app_tag = portapack::spi_flash::image_tag_vor_rx */ {'P', 'V', 'R', 'X'},
/*.m4_app_offset = */ 0x00000000, // will be filled at compile time
};
}
+341
View File
@@ -0,0 +1,341 @@
/*
* Copyright (C) 2026 PortaPack Mayhem
*
* 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; if not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "ui_vor_rx.hpp"
#include "audio.hpp"
#include "string_format.hpp"
#include <algorithm>
#include <cstdint>
using namespace portapack;
using namespace ui;
namespace ui::external_app::vor_rx {
void VorLogger::write_header() {
log_file.write_raw("Time;Course;Radial;Deviation;Quality;Flag;");
}
void VorLogger::log_status(const VorRxStatusDataMessage& message, uint16_t course_deg) {
const int16_t deviation = static_cast<int16_t>((static_cast<int32_t>(message.radial_deg) - static_cast<int32_t>(course_deg) + 540) % 360 - 180);
std::string row = ";";
row += to_string_dec_uint(course_deg);
row += ";" + to_string_dec_uint(message.radial_deg);
row += ";" + std::to_string(deviation);
row += ";" + to_string_dec_uint(message.quality);
row += ";" + std::string(message.valid ? (message.to_from ? "TO" : "FROM") : "--");
log_file.write_entry(rtc_time::now(), row);
}
VorCdiIndicator::VorCdiIndicator(Point position)
: Widget{{position, {screen_width, 32}}} {
}
void VorCdiIndicator::set_course(uint16_t course_deg) {
if (course_deg_ != course_deg) {
course_deg_ = course_deg;
set_dirty();
}
}
void VorCdiIndicator::set_radial(uint16_t radial_deg) {
if (radial_deg_ != radial_deg) {
radial_deg_ = radial_deg;
set_dirty();
}
}
void VorCdiIndicator::set_valid(bool valid) {
if (valid_ != valid) {
valid_ = valid;
set_dirty();
}
}
int32_t VorCdiIndicator::normalize_signed_degrees(int32_t degrees) {
while (degrees <= -180) {
degrees += 360;
}
while (degrees > 180) {
degrees -= 360;
}
return degrees;
}
void VorCdiIndicator::paint(Painter& painter) {
const auto r = screen_rect();
const auto theme = Theme::getInstance();
const auto line_color = valid_ ? theme->fg_light->foreground : theme->bg_medium->foreground;
const auto needle_color = valid_ ? theme->fg_red->foreground : theme->bg_medium->foreground;
// Clear background so old needle positions don't linger.
painter.fill_rectangle(r, theme->bg_darkest->background);
const auto center_x = static_cast<Coord>(r.left() + r.width() / 2);
const auto center_y = static_cast<Coord>(r.top() + r.height() / 2);
// Horizontal scale line.
painter.draw_hline({static_cast<Coord>(r.left() + 8), center_y}, r.width() - 16, line_color);
// Evenly spaced tick marks, longer at center.
constexpr int32_t tick_spacing = 40;
for (int32_t tick = -2; tick <= 2; ++tick) {
const auto x = static_cast<Coord>(center_x + tick * tick_spacing);
const auto len = (tick == 0) ? 14 : 8;
painter.draw_vline({x, static_cast<Coord>(center_y - len / 2)}, len, line_color);
}
// Deviation needle, clamped to +/-10 degrees full-scale.
const int32_t deviation = normalize_signed_degrees(static_cast<int32_t>(radial_deg_) - static_cast<int32_t>(course_deg_));
const int32_t scaled = std::max<int32_t>(-10, std::min<int32_t>(10, deviation));
// +/-10 deg full-scale maps to +/-2 ticks (2 * tick_spacing); the division
// is exact for the clamped range so no rounding is needed.
const int16_t needle_offset = static_cast<int16_t>((scaled * (2 * tick_spacing)) / 10);
const auto needle_x = static_cast<Coord>(center_x + needle_offset);
painter.draw_vline({needle_x, static_cast<Coord>(r.top() + 4)}, r.height() - 8, needle_color);
}
VorRxView::VorRxView(NavigationView& nav)
: nav_{nav} {
add_children({&field_rf_amp,
&field_lna,
&field_vga,
&field_volume,
&field_frequency,
&rssi,
&channel,
&audio,
&labels,
&text_status,
&text_band,
&text_next,
&field_course,
&text_course_unit,
&field_calibration,
&text_calib_unit,
&text_radial,
&text_flag,
&text_cdi_title,
&cdi_indicator,
&check_log,
&button_start_stop});
field_frequency.set_step(8333);
if (field_frequency.value() == 0) {
field_frequency.set_value(110'000'000);
}
field_course.set_value(0);
field_course.on_change = [this](int32_t) {
update_cdi();
};
field_calibration.set_value(0);
field_calibration.on_change = [this](int32_t) {
refresh_radial();
};
logger = std::make_unique<VorLogger>();
check_log.set_value(logging_);
check_log.on_select = [this](Checkbox&, bool v) {
logging_ = v;
update_logging();
};
update_logging();
button_start_stop.on_select = [this](Button&) {
if (running_) {
stop_receiver();
} else {
start_receiver();
}
};
start_receiver();
}
VorRxView::~VorRxView() {
stop_receiver();
}
void VorRxView::focus() {
field_frequency.focus();
}
void VorRxView::start_receiver() {
baseband::run_prepared_image(portapack::memory::map::m4_code.base());
baseband::set_vor_config(true);
radial_filter_valid_ = false;
flag_state_ = 0;
receiver_model.set_hidden_offset(0);
receiver_model.set_modulation(ReceiverModel::Mode::AMAudio);
receiver_model.set_frequency_step(8333);
receiver_model.set_sampling_rate(3072000);
receiver_model.set_baseband_bandwidth(1750000);
receiver_model.enable();
// enable() applies the AM configuration, which forces the audio codec to
// 12 kHz. The VOR baseband keeps its channel at 48 kHz (so the 9960 Hz
// subcarrier stays representable), so re-assert 48 kHz audio afterwards.
audio::set_rate(audio::Rate::Hz_48000);
audio::output::start();
running_ = true;
update_status();
}
void VorRxView::stop_receiver() {
if (!running_) {
return;
}
running_ = false;
baseband::set_vor_config(false);
receiver_model.disable();
baseband::shutdown();
audio::output::stop();
update_status();
}
void VorRxView::update_status() {
text_status.set(running_ ? "Running" : "Idle");
button_start_stop.set_text(running_ ? "Stop" : "Start");
}
void VorRxView::update_logging() {
if (logger && logging_) {
logger->append(logs_dir / (std::string("VOR_") + to_string_timestamp(rtc_time::now()) + ".CSV"));
logger->write_header();
}
}
void VorRxView::on_vor_status(const VorRxStatusDataMessage& message) {
if (!running_) {
return;
}
last_radial_deg_ = message.radial_deg;
last_valid_ = message.valid;
have_status_ = true;
if (message.valid) {
last_radial_deg_ = smooth_radial(message.radial_deg);
} else {
// Drop the filter history so a fresh lock doesn't drag from stale data.
radial_filter_valid_ = false;
}
text_next.set(message.valid ? "Locked" : "Searching");
refresh_radial();
if (logger && logging_) {
VorRxStatusDataMessage calibrated = message;
calibrated.radial_deg = calibrated_radial(last_radial_deg_);
calibrated.to_from = (flag_state_ == 2);
logger->log_status(calibrated, field_course.value());
}
}
uint16_t VorRxView::smooth_radial(uint16_t radial_deg) {
// Wrapped exponential moving average. At ~10 updates/s blending 20% of each
// new reading (alpha = 0.8) gives a ~0.5 s time constant while cutting the
// jitter by ~3x. Stepping along the shortest arc in 1/64 deg fixed point
// handles the 0/360 deg wrap without any trig (which would otherwise pull
// newlib's float sin/cos/atan2 argument-reduction code into flash ROM).
constexpr int32_t scale = 64;
constexpr int32_t full_circle = 360 * scale;
const int32_t target = static_cast<int32_t>(radial_deg) * scale;
if (!radial_filter_valid_) {
radial_smoothed_fp_ = target;
radial_filter_valid_ = true;
} else {
int32_t diff = (target - radial_smoothed_fp_) % full_circle;
if (diff < -full_circle / 2) {
diff += full_circle;
} else if (diff > full_circle / 2) {
diff -= full_circle;
}
// 20% step toward the new reading (1 - alpha).
radial_smoothed_fp_ += diff / 5;
radial_smoothed_fp_ %= full_circle;
if (radial_smoothed_fp_ < 0) {
radial_smoothed_fp_ += full_circle;
}
}
return static_cast<uint16_t>((radial_smoothed_fp_ + scale / 2) / scale) % 360;
}
uint16_t VorRxView::calibrated_radial(uint16_t radial_deg) const {
int32_t value = (static_cast<int32_t>(radial_deg) + field_calibration.value()) % 360;
if (value < 0) {
value += 360;
}
return static_cast<uint16_t>(value);
}
void VorRxView::refresh_radial() {
if (!have_status_) {
return;
}
const uint16_t radial = calibrated_radial(last_radial_deg_);
text_radial.set(to_string_dec_uint(radial, 3) + " deg");
text_flag.set(to_from_label(radial));
cdi_indicator.set_radial(radial);
cdi_indicator.set_valid(last_valid_);
}
const char* VorRxView::to_from_label(uint16_t radial_deg) {
if (!last_valid_) {
flag_state_ = 0;
return "--";
}
// TO/FROM is set by the selected OBS course relative to the received radial,
// not by the radial alone. Take the difference wrapped to [-180, 180]: the
// switch is at the 90 deg abeam point. |diff| < 90 means the selected course
// leads away from the station (FROM); |diff| > 90 means toward it (TO).
int32_t diff = (static_cast<int32_t>(radial_deg) - field_course.value() + 540) % 360 - 180;
const int32_t adiff = (diff < 0) ? -diff : diff;
// Hysteresis: hold the current flag within a +/-5 deg dead zone around the
// 90 deg boundary so noise near abeam doesn't rapidly toggle TO/FROM.
if (adiff < 85) {
flag_state_ = 1; // FROM
} else if (adiff > 95) {
flag_state_ = 2; // TO
}
if (flag_state_ == 1) return "FROM";
if (flag_state_ == 2) return "TO";
return "--"; // abeam / ambiguous
}
void VorRxView::update_cdi() {
cdi_indicator.set_course(field_course.value());
}
} // namespace ui::external_app::vor_rx
+200
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@@ -0,0 +1,200 @@
/*
* Copyright (C) 2026 PortaPack Mayhem
*
* 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; if not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __UI_VOR_RX_H__
#define __UI_VOR_RX_H__
#include "audio.hpp"
#include "baseband_api.hpp"
#include "file_path.hpp"
#include "log_file.hpp"
#include "rtc_time.hpp"
#include "portapack.hpp"
#include "ui.hpp"
#include "ui_audio.hpp"
#include "ui_channel.hpp"
#include "ui_freq_field.hpp"
#include "ui_navigation.hpp"
#include "ui_receiver.hpp"
#include "ui_rssi.hpp"
namespace ui::external_app::vor_rx {
class VorLogger {
public:
Optional<File::Error> append(const std::filesystem::path& filename) {
return log_file.append(filename);
}
void write_header();
void log_status(const VorRxStatusDataMessage& message, uint16_t course_deg);
private:
LogFile log_file{};
};
class VorCdiIndicator : public Widget {
public:
VorCdiIndicator(Point position);
void set_course(uint16_t course_deg);
void set_radial(uint16_t radial_deg);
void set_valid(bool valid);
void paint(Painter& painter) override;
private:
static int32_t normalize_signed_degrees(int32_t degrees);
uint16_t course_deg_{0};
uint16_t radial_deg_{0};
bool valid_{false};
};
class VorRxView : public View {
public:
VorRxView(NavigationView& nav);
~VorRxView();
void focus() override;
std::string title() const override { return "VOR RX"; }
private:
void start_receiver();
void stop_receiver();
void update_status();
void on_vor_status(const VorRxStatusDataMessage& message);
void update_cdi();
void refresh_radial();
uint16_t calibrated_radial(uint16_t radial_deg) const;
uint16_t smooth_radial(uint16_t radial_deg);
const char* to_from_label(uint16_t radial_deg);
void update_logging();
NavigationView& nav_;
bool running_{false};
bool logging_{false};
bool have_status_{false};
uint16_t last_radial_deg_{0};
bool last_valid_{false};
uint8_t flag_state_{0}; // TO/FROM hysteresis: 0=unknown, 1=FROM, 2=TO
// Circular exponential moving average of the radial. Each 100 ms estimate
// is noisy (~10 deg std even when locked), so blend it along the shortest
// arc in 1/64 deg fixed point to average correctly across the 0/360 deg
// wrap without trig.
bool radial_filter_valid_{false};
int32_t radial_smoothed_fp_{0};
RxFrequencyField field_frequency{
{UI_POS_X(0), UI_POS_Y(0)},
nav_};
RFAmpField field_rf_amp{
{UI_POS_X(13), UI_POS_Y(0)}};
LNAGainField field_lna{
{UI_POS_X(15), UI_POS_Y(0)}};
VGAGainField field_vga{
{UI_POS_X(18), UI_POS_Y(0)}};
AudioVolumeField field_volume{
{screen_width - 2 * 8, UI_POS_Y(0)}};
RSSI rssi{
{UI_POS_X(21), 0, UI_POS_WIDTH_REMAINING(21) - UI_POS_WIDTH(2), 4}};
Channel channel{
{UI_POS_X(21), 5, UI_POS_WIDTH_REMAINING(21) - UI_POS_WIDTH(2), 4}};
Audio audio{
{UI_POS_X(21), 10, UI_POS_WIDTH_REMAINING(21) - UI_POS_WIDTH(2), 4}};
NumberField field_course{
{UI_POS_X(14), UI_POS_Y(4)},
3,
{0, 359},
1,
'0'};
NumberField field_calibration{
{UI_POS_X(14), UI_POS_Y(7)},
4,
{-359, 359},
1,
' '};
Labels labels{
{{UI_POS_X(0), UI_POS_Y(1)}, "Status:", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(2)}, "VOR Band:", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(3)}, "Decoder:", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(4)}, "Course (OBS):", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(5)}, "Rec. Radial:", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(6)}, "Flag:", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(7)}, "Calibration:", Theme::getInstance()->fg_light->foreground}};
Text text_status{
{UI_POS_X(14), UI_POS_Y(1), UI_POS_WIDTH_REMAINING(14), UI_POS_HEIGHT(1)},
"Idle"};
Text text_band{
{UI_POS_X(14), UI_POS_Y(2), UI_POS_WIDTH_REMAINING(14), UI_POS_HEIGHT(1)},
"108.00-117.95MHz"};
Text text_next{
{UI_POS_X(14), UI_POS_Y(3), UI_POS_WIDTH_REMAINING(14), UI_POS_HEIGHT(1)},
"Pending"};
Text text_course_unit{
{UI_POS_X(18), UI_POS_Y(4), UI_POS_WIDTH_REMAINING(18), UI_POS_HEIGHT(1)},
"deg"};
Text text_radial{
{UI_POS_X(14), UI_POS_Y(5), UI_POS_WIDTH_REMAINING(14), UI_POS_HEIGHT(1)},
"--"};
Text text_flag{
{UI_POS_X(14), UI_POS_Y(6), UI_POS_WIDTH_REMAINING(14), UI_POS_HEIGHT(1)},
"--"};
Text text_calib_unit{
{UI_POS_X(19), UI_POS_Y(7), UI_POS_WIDTH_REMAINING(19), UI_POS_HEIGHT(1)},
"deg"};
Text text_cdi_title{
{UI_POS_X(0), UI_POS_Y(9), UI_POS_WIDTH_REMAINING(0), UI_POS_HEIGHT(1)},
"Course Deviation Indicator"};
VorCdiIndicator cdi_indicator{
{UI_POS_X(0), UI_POS_Y(10)}};
std::unique_ptr<VorLogger> logger{};
Button button_start_stop{
{UI_POS_X(9), UI_POS_Y(14), UI_POS_WIDTH(12), UI_POS_HEIGHT(2)},
"Start"};
Checkbox check_log{
{UI_POS_X(7), UI_POS_Y(17)},
3,
"LOG to SD Card",
true};
MessageHandlerRegistration message_handler_vor_status{
Message::ID::VorRxStatusData,
[this](const Message* p) {
const auto message = *reinterpret_cast<const VorRxStatusDataMessage*>(p);
on_vor_status(message);
}};
};
} // namespace ui::external_app::vor_rx
#endif // __UI_VOR_RX_H__
+85
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@@ -0,0 +1,85 @@
/*
* Copyright (C) 2026 PortaPack Mayhem
*
* 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; if not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "ui.hpp"
#include "ui_vor_tx.hpp"
#include "ui_navigation.hpp"
#include "external_app.hpp"
namespace ui::external_app::vor_tx {
void initialize_app(ui::NavigationView& nav) {
nav.push<VorTxView>();
}
} // namespace ui::external_app::vor_tx
extern "C" {
__attribute__((section(".external_app.app_vor_tx.application_information"), used)) application_information_t _application_information_vor_tx = {
/*.memory_location = */ (uint8_t*)0x00000000,
/*.externalAppEntry = */ ui::external_app::vor_tx::initialize_app,
/*.header_version = */ CURRENT_HEADER_VERSION,
/*.app_version = */ VERSION_MD5,
/*.app_name = */ "VOR TX",
/*.bitmap_data = */ {
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x80,
0x01,
0xC0,
0x03,
0xE0,
0x07,
0xF0,
0x0F,
0xF8,
0x1F,
0xF8,
0x1F,
0xF0,
0x0F,
0xE0,
0x07,
0xC0,
0x03,
0x80,
0x01,
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
},
/*.icon_color = */ ui::Color::green().v,
/*.menu_location = */ app_location_t::TX,
/*.desired_menu_position = */ -1,
/*.m4_app_tag = portapack::spi_flash::image_tag_vor_tx */ {'P', 'V', 'T', 'X'},
/*.m4_app_offset = */ 0x00000000, // will be filled at compile time
};
}
+133
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@@ -0,0 +1,133 @@
/*
* Copyright (C) 2026 PortaPack Mayhem
*
* 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; if not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "ui_vor_tx.hpp"
#include "string_format.hpp"
#include "ui_textentry.hpp"
using namespace portapack;
using namespace ui;
namespace ui::external_app::vor_tx {
VorTxView::VorTxView(NavigationView& nav)
: nav_{nav} {
baseband::run_prepared_image(portapack::memory::map::m4_code.base());
add_children({&labels,
&field_radial,
&text_radial_unit,
&check_ident,
&button_ident_text,
&text_status,
&tx_view});
field_radial.set_value(radial_);
field_radial.on_change = [this](int32_t v) {
radial_ = v;
if (transmitting_) {
update_config();
}
};
check_ident.set_value(ident_);
check_ident.on_select = [this](Checkbox&, bool v) {
ident_ = v;
if (transmitting_) {
update_config();
}
};
button_ident_text.set_text(ident_text_);
button_ident_text.on_select = [this](Button&) {
text_prompt(nav_, ident_text_, 7, ENTER_KEYBOARD_MODE_ALPHA, [this](std::string&) {
button_ident_text.set_text(ident_text_);
if (transmitting_) {
update_config();
}
});
};
tx_view.on_edit_frequency = [this, &nav]() {
auto new_view = nav.push<FrequencyKeypadView>(transmitter_model.target_frequency());
new_view->on_changed = [this](rf::Frequency f) {
transmitter_model.set_target_frequency(f);
};
};
tx_view.on_start = [this]() {
if (tx_acknowledged_) {
start_tx();
return;
}
nav_.display_modal(
"TX WARNING",
"VOR is an aviation nav\nband! TX only into a\ndummy load.",
YESNO,
[this](bool choice) {
if (choice) {
tx_acknowledged_ = true;
start_tx();
} else {
tx_view.set_transmitting(false);
}
});
};
tx_view.on_stop = [this]() {
stop_tx();
};
}
VorTxView::~VorTxView() {
transmitter_model.disable();
baseband::shutdown();
}
void VorTxView::focus() {
tx_view.focus();
}
void VorTxView::update_config() {
baseband::set_vor_tx_config(static_cast<uint16_t>(radial_), ident_, ident_text_);
}
void VorTxView::start_tx() {
transmitter_model.set_sampling_rate(1536000);
transmitter_model.set_baseband_bandwidth(1750000);
transmitter_model.enable();
update_config();
transmitting_ = true;
tx_view.set_transmitting(true);
text_status.set("TX radial " + to_string_dec_uint(radial_));
set_dirty();
}
void VorTxView::stop_tx() {
transmitter_model.disable();
transmitting_ = false;
tx_view.set_transmitting(false);
text_status.set("Idle");
set_dirty();
}
} // namespace ui::external_app::vor_tx
+113
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@@ -0,0 +1,113 @@
/*
* Copyright (C) 2026 PortaPack Mayhem
*
* 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; if not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __UI_VOR_TX_H__
#define __UI_VOR_TX_H__
#include "app_settings.hpp"
#include "baseband_api.hpp"
#include "portapack.hpp"
#include "radio_state.hpp"
#include "ui.hpp"
#include "ui_navigation.hpp"
#include "ui_receiver.hpp"
#include "ui_transmitter.hpp"
namespace ui::external_app::vor_tx {
class VorTxView : public View {
public:
VorTxView(NavigationView& nav);
~VorTxView();
void focus() override;
std::string title() const override { return "VOR TX"; }
private:
void start_tx();
void stop_tx();
void update_config();
NavigationView& nav_;
bool transmitting_{false};
bool tx_acknowledged_{false};
uint32_t radial_{0};
bool ident_{true};
std::string ident_text_{"VOR"};
TxRadioState radio_state_{
113'500'000 /* frequency */,
1750000 /* bandwidth */,
1536000 /* sampling rate */
};
app_settings::SettingsManager settings_{
"tx_vor",
app_settings::Mode::TX,
{
{"radial"sv, &radial_},
{"ident"sv, &ident_},
{"ident_text"sv, &ident_text_},
}};
Labels labels{
{{UI_POS_X(0), UI_POS_Y(1)}, "Radial:", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(5)}, "Ident:", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(8)}, "Status:", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(10)}, "Lab use: set any freq &", Theme::getInstance()->fg_light->foreground},
{{UI_POS_X(0), UI_POS_Y(11)}, "TX into a dummy load.", Theme::getInstance()->fg_light->foreground}};
NumberField field_radial{
{UI_POS_X(8), UI_POS_Y(1)},
3,
{0, 359},
1,
'0'};
Text text_radial_unit{
{UI_POS_X(12), UI_POS_Y(1), UI_POS_WIDTH(4), UI_POS_HEIGHT(1)},
"deg"};
Checkbox check_ident{
{UI_POS_X(0), UI_POS_Y(3)},
13,
"CW identifier",
true};
Button button_ident_text{
{UI_POS_X(8), UI_POS_Y(5), UI_POS_WIDTH(10), UI_POS_HEIGHT(2)},
"VOR"};
Text text_status{
{UI_POS_X(8), UI_POS_Y(8), UI_POS_WIDTH_REMAINING(8), UI_POS_HEIGHT(1)},
"Idle"};
TransmitterView tx_view{
(int16_t)UI_POS_Y_BOTTOM(4),
8333,
1750000};
};
} // namespace ui::external_app::vor_tx
#endif // __UI_VOR_TX_H__
+14
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@@ -516,6 +516,20 @@ DeclareTargets(PFUT flash_utility)
set(add_to_firmware FALSE)
set(MODE_FLAGS "-O3")
### VOR TX
set(MODE_CPPSRC
proc_vor_tx.cpp
)
DeclareTargets(PVTX vor_tx)
### VOR RX
set(MODE_CPPSRC
proc_vor_rx.cpp
)
DeclareTargets(PVRX vor_rx)
### FLEX RX
set(MODE_CPPSRC
+272
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@@ -0,0 +1,272 @@
/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
* Copyright (C) 2026 PortaPack Mayhem
*
* 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 "proc_vor_rx.hpp"
#include "audio_output.hpp"
#include "audio_dma.hpp"
#include "dsp_iir_config.hpp"
#include "portapack_shared_memory.hpp"
#include "event_m4.hpp"
#include <algorithm>
namespace {
constexpr float kPi = 3.14159265358979323846f;
}
VorRx::VorRx() {
channel_spectrum.set_decimation_factor(1);
baseband_thread.start();
rssi_thread.start();
}
void VorRx::execute(const buffer_c8_t& buffer) {
if (!configured) {
return;
}
const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
channel_spectrum.feed(decim_1_out, channel_filter_low_f, channel_filter_high_f, channel_filter_transition);
// No decim_2 stage: the standard AM decim_2 filter is a ~4.5 kHz low-pass
// that would attenuate the 9960 Hz VOR subcarrier by ~60 dB and destroy the
// reference phase. The channel stays at 48 kHz so the subcarrier survives.
const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
feed_channel_stats(channel_out);
auto audio = demod_am.execute(channel_out, audio_buffer);
if (vor_enabled) {
process_vor_metrics(audio);
// Strip the 9960 Hz subcarrier from the audible signal (the metrics
// above still ran on the unfiltered audio so the decode is unaffected).
audio_lpf_1.execute_in_place(audio);
audio_lpf_2.execute_in_place(audio);
}
audio_compressor.execute_in_place(audio);
audio_output.write(audio);
}
void VorRx::on_message(const Message* const message) {
switch (message->id) {
case Message::ID::UpdateSpectrum:
case Message::ID::SpectrumStreamingConfig:
channel_spectrum.on_message(message);
break;
case Message::ID::VorRxConfigure:
configure_vor(*reinterpret_cast<const VorRxConfigureMessage*>(message));
break;
case Message::ID::AMConfigure:
configure(*reinterpret_cast<const AMConfigureMessage*>(message));
break;
default:
break;
}
}
void VorRx::configure(const AMConfigureMessage& message) {
decim_0.configure(message.decim_0_filter.taps);
decim_1.configure(message.decim_1_filter.taps);
channel_filter.configure(message.channel_filter.taps, channel_filter_decimation_factor);
constexpr size_t decim_0_output_fs = baseband_fs / decim_0.decimation_factor;
constexpr size_t decim_1_output_fs = decim_0_output_fs / decim_1.decimation_factor;
constexpr size_t channel_filter_input_fs = decim_1_output_fs;
channel_filter_low_f = message.channel_filter.low_frequency_normalized * channel_filter_input_fs;
channel_filter_high_f = message.channel_filter.high_frequency_normalized * channel_filter_input_fs;
channel_filter_transition = message.channel_filter.transition_normalized * channel_filter_input_fs;
channel_spectrum.set_decimation_factor(message.channel_spectrum_decimation_factor);
audio_output.configure(message.audio_hpf_lpf_config);
configured = true;
}
void VorRx::PhaseOscillator::configure(float frequency_hz, float sample_rate_hz) {
const float step = 2.0f * kPi * frequency_hz / sample_rate_hz;
step_sin = sinf(step);
step_cos = cosf(step);
sin_v = 0.0f;
cos_v = 1.0f;
}
void VorRx::PhaseOscillator::advance() {
const float next_cos = (cos_v * step_cos) - (sin_v * step_sin);
const float next_sin = (sin_v * step_cos) + (cos_v * step_sin);
cos_v = next_cos;
sin_v = next_sin;
}
void VorRx::PhaseOscillator::renormalize() {
// The recursive rotator slowly drifts in amplitude over long runs;
// rescale to the unit circle so accumulated tone levels stay meaningful.
const float mag = sqrtf((cos_v * cos_v) + (sin_v * sin_v));
if (mag > 0.0f) {
const float inv = 1.0f / mag;
cos_v *= inv;
sin_v *= inv;
}
}
void VorRx::configure_vor(const VorRxConfigureMessage& message) {
vor_enabled = message.enabled;
vor_reference_osc.configure(vor_reference_hz, 48000.0f);
vor_subcarrier_osc.configure(vor_subcarrier_hz, 48000.0f);
audio_lpf_1.configure(audio_48k_lpf_3200hz_config);
audio_lpf_2.configure(audio_48k_lpf_3200hz_config);
vor_ref_i = 0.0f;
vor_ref_q = 0.0f;
vor_var_i = 0.0f;
vor_var_q = 0.0f;
vor_dc_sum = 0.0f;
vor_sub_lp_i = 0.0f;
vor_sub_lp_q = 0.0f;
vor_sub_prev_i = 0.0f;
vor_sub_prev_q = 0.0f;
vor_sample_count = 0;
}
uint16_t VorRx::normalize_degrees(float degrees) {
while (degrees < 0.0f) {
degrees += 360.0f;
}
while (degrees >= 360.0f) {
degrees -= 360.0f;
}
return static_cast<uint16_t>(degrees + 0.5f);
}
void VorRx::send_vor_status(uint16_t phase_deg, uint16_t radial_deg, uint16_t ref_level, uint16_t var_level, uint8_t quality, bool valid, bool to_from) {
const VorRxStatusDataMessage message{phase_deg, radial_deg, ref_level, var_level, quality, valid, to_from};
shared_memory.application_queue.push(message);
}
void VorRx::process_vor_metrics(const buffer_f32_t& audio) {
for (size_t i = 0; i < audio.count; ++i) {
const float sample = audio.p[i];
const float ref_cos = vor_reference_osc.cosine();
const float ref_sin = vor_reference_osc.sine();
const float sub_cos = vor_subcarrier_osc.cosine();
const float sub_sin = vor_subcarrier_osc.sine();
// Variable signal: 30 Hz amplitude modulation of the carrier envelope.
// Correlate the envelope against a local 30 Hz tone (DC rejected because
// the window spans an exact integer number of 30 Hz cycles).
vor_dc_sum += sample;
vor_var_i += sample * ref_cos;
vor_var_q -= sample * ref_sin;
// Reference signal: 30 Hz FM on the 9960 Hz subcarrier. Quadrature
// down-convert the subcarrier, low-pass to its +/-480 Hz baseband, then
// FM-demodulate (phase difference between successive samples).
const float sc_i = sample * sub_cos;
const float sc_q = -sample * sub_sin;
vor_sub_lp_i += (1.0f - vor_sub_lp_alpha) * (sc_i - vor_sub_lp_i);
vor_sub_lp_q += (1.0f - vor_sub_lp_alpha) * (sc_q - vor_sub_lp_q);
const float num = (vor_sub_lp_q * vor_sub_prev_i) - (vor_sub_lp_i * vor_sub_prev_q);
const float den = (vor_sub_lp_i * vor_sub_prev_i) + (vor_sub_lp_q * vor_sub_prev_q);
const float fm = atan2f(num, den);
vor_sub_prev_i = vor_sub_lp_i;
vor_sub_prev_q = vor_sub_lp_q;
vor_ref_i += fm * ref_cos;
vor_ref_q -= fm * ref_sin;
vor_reference_osc.advance();
vor_subcarrier_osc.advance();
++vor_sample_count;
if (vor_sample_count < vor_window_samples) {
continue;
}
const float inv_n = 1.0f / static_cast<float>(vor_window_samples);
const float variable_phase = atan2f(vor_var_q, vor_var_i);
const float reference_phase = atan2f(vor_ref_q, vor_ref_i);
// Real VOR radials increase clockwise, i.e. the variable tone lags the
// reference by the bearing. The decoder therefore reports
// (reference - variable); the opposite order mirrors every bearing to
// 360 - true. Add back the receive-chain phase lag (see
// vor_ref_phase_lag_deg): with this subtraction order the delayed
// reference makes the raw radial read low, so the correction is added.
float phase_diff = ((reference_phase - variable_phase) * 180.0f / kPi) + vor_ref_phase_lag_deg;
while (phase_diff < 0.0f) {
phase_diff += 360.0f;
}
while (phase_diff >= 360.0f) {
phase_diff -= 360.0f;
}
// Scale-invariant lock metrics (independent of RF/AGC level):
// - var_ratio: 30 Hz AM depth vs. carrier DC (~0.30 for a real VOR).
// - ref_amp: FM-demodulated 30 Hz amplitude (phase-only, so it does
// not depend on signal amplitude, ~0.065 when locked).
const float dc_level = vor_dc_sum * inv_n;
const float var_amp = 2.0f * sqrtf((vor_var_i * vor_var_i) + (vor_var_q * vor_var_q)) * inv_n;
const float ref_amp = 2.0f * sqrtf((vor_ref_i * vor_ref_i) + (vor_ref_q * vor_ref_q)) * inv_n;
const float var_ratio = (dc_level > 0.0f) ? (var_amp / dc_level) : 0.0f;
const auto phase_deg = normalize_degrees(phase_diff);
const auto radial_deg = phase_deg;
const auto ref_level = static_cast<uint16_t>(std::min(65535.0f, ref_amp * 10000.0f));
const auto var_level = static_cast<uint16_t>(std::min(65535.0f, var_ratio * 1000.0f));
const bool valid = (ref_amp > 0.03f) && (var_ratio > 0.15f);
// TO/FROM depends on the operator-selected OBS course, which only the
// application knows, so it is derived there (see VorRxView). Emit a
// stable placeholder here rather than a radial-only guess.
const bool to_from = false;
uint8_t quality = 0;
if (valid) {
const float q = (ref_amp / 0.065f) * 100.0f;
quality = static_cast<uint8_t>(std::min(100.0f, std::max(0.0f, q)));
}
send_vor_status(phase_deg, radial_deg, ref_level, var_level, quality, valid, to_from);
vor_reference_osc.renormalize();
vor_subcarrier_osc.renormalize();
vor_sample_count = 0;
vor_ref_i = 0.0f;
vor_ref_q = 0.0f;
vor_var_i = 0.0f;
vor_var_q = 0.0f;
vor_dc_sum = 0.0f;
}
}
int main() {
audio::dma::init_audio_out();
EventDispatcher event_dispatcher{std::make_unique<VorRx>()};
event_dispatcher.run();
return 0;
}
+150
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@@ -0,0 +1,150 @@
/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
* Copyright (C) 2026 PortaPack Mayhem
*
* 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.
*/
#ifndef __PROC_VOR_RX_H__
#define __PROC_VOR_RX_H__
#include "baseband_processor.hpp"
#include "baseband_thread.hpp"
#include "rssi_thread.hpp"
#include "dsp_decimate.hpp"
#include "dsp_demodulate.hpp"
#include "dsp_iir.hpp"
#include "audio_compressor.hpp"
#include "audio_output.hpp"
#include "spectrum_collector.hpp"
#include <array>
#include <cstdint>
#include <cmath>
// Standalone VOR receiver baseband.
// Demodulates the AM channel at 48 kHz (so the 9960 Hz subcarrier stays
// representable) and decodes the 30 Hz reference vs. variable phase to derive
// the radial.
class VorRx : public BasebandProcessor {
public:
VorRx();
void execute(const buffer_c8_t& buffer) override;
void on_message(const Message* const message) override;
private:
static constexpr size_t baseband_fs = 3072000;
// VOR keeps the channel at 48 kHz instead of the AM audio 12 kHz, so the
// 9960 Hz subcarrier stays below Nyquist. The standard AM decim_2 stage is
// therefore omitted (its ~4.5 kHz low-pass would remove the subcarrier).
static constexpr size_t channel_filter_decimation_factor = 1;
std::array<complex16_t, 512> dst{};
const buffer_c16_t dst_buffer{
dst.data(),
dst.size()};
std::array<float, 32> audio{};
const buffer_f32_t audio_buffer{
audio.data(),
audio.size()};
dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0{};
dsp::decimate::FIRC16xR16x32Decim8 decim_1{};
dsp::decimate::FIRAndDecimateComplex channel_filter{};
int32_t channel_filter_low_f = 0;
int32_t channel_filter_high_f = 0;
int32_t channel_filter_transition = 0;
bool configured{false};
bool vor_enabled{false};
static constexpr float vor_reference_hz{30.0f};
static constexpr float vor_subcarrier_hz{9960.0f};
// 100 ms at 48 kHz (exactly 3 cycles of 30 Hz)
static constexpr uint32_t vor_window_samples{4800};
// One-pole low-pass to isolate the +/-480 Hz FM subcarrier baseband
// after quadrature down-conversion (corner ~600 Hz at 48 kHz).
static constexpr float vor_sub_lp_alpha{0.9245f};
// Fixed phase lag the receive chain adds to the recovered 30 Hz reference
// tone, expressed in degrees at 30 Hz. It comes almost entirely from the
// one-pole subcarrier low-pass above (~2.75 deg of lag at 30 Hz for
// alpha = 0.9245) plus a ~0.1 deg half-sample delay in the FM
// differentiator. Because the reference tone is delayed, the raw radial
// (reference - variable) reads low by this amount, so we add it back.
// Value verified by a TX->RX loopback (proc_vor_tx fed through this
// decoder): every transmitted radial decoded ~3.2 deg low before this
// correction, and on-bearing afterwards.
static constexpr float vor_ref_phase_lag_deg{3.2f};
struct PhaseOscillator {
float sin_v{0.0f};
float cos_v{1.0f};
float step_sin{0.0f};
float step_cos{1.0f};
void configure(float frequency_hz, float sample_rate_hz);
float cosine() const { return cos_v; }
float sine() const { return sin_v; }
void advance();
void renormalize();
} vor_reference_osc{}, vor_subcarrier_osc{};
// 30 Hz DFT accumulators for the variable (AM) and reference (FM) tones.
float vor_ref_i{0.0f};
float vor_ref_q{0.0f};
float vor_var_i{0.0f};
float vor_var_q{0.0f};
float vor_dc_sum{0.0f};
// Subcarrier quadrature down-converter / FM-demodulator state.
float vor_sub_lp_i{0.0f};
float vor_sub_lp_q{0.0f};
float vor_sub_prev_i{0.0f};
float vor_sub_prev_q{0.0f};
uint32_t vor_sample_count{0};
dsp::demodulate::AM demod_am{};
// Two cascaded 2nd-order Butterworth low-passes (4th-order total) that strip
// the 9960 Hz FM subcarrier out of the audio before it reaches the speaker.
// The channel is kept wide (48 kHz) so the subcarrier survives for the
// radial decode, so it must be filtered out of the audible path here.
IIRBiquadFilter audio_lpf_1{};
IIRBiquadFilter audio_lpf_2{};
FeedForwardCompressor audio_compressor{};
AudioOutput audio_output{};
SpectrumCollector channel_spectrum{};
/* NB: Threads should be the last members in the class definition. */
#ifdef PRALINE
BasebandThread baseband_thread{baseband_fs, this, baseband::Direction::Receive,
/*auto_start*/ false};
RSSIThread rssi_thread{/*auto_start*/ false};
#else
BasebandThread baseband_thread{baseband_fs, this, baseband::Direction::Receive};
RSSIThread rssi_thread{};
#endif
void configure(const AMConfigureMessage& message);
void configure_vor(const VorRxConfigureMessage& message);
void process_vor_metrics(const buffer_f32_t& audio);
void send_vor_status(uint16_t phase_deg, uint16_t radial_deg, uint16_t ref_level, uint16_t var_level, uint8_t quality, bool valid, bool to_from);
static uint16_t normalize_degrees(float degrees);
};
#endif /*__PROC_VOR_RX_H__*/
+169
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@@ -0,0 +1,169 @@
/*
* Copyright (C) 2026 PortaPack Mayhem
*
* 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; if not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "proc_vor_tx.hpp"
#include "morse.hpp"
#include "sine_table_int8.hpp"
#include "event_m4.hpp"
void VorTxProcessor::execute(const buffer_c8_t& buffer) {
for (size_t i = 0; i < buffer.count; i++) {
if (!configured) {
buffer.p[i] = {0, 0};
continue;
}
// 30 Hz reference and variable tones (same frequency, offset by the radial).
const int32_t ref_sine = sine_table_i8[(phase_30 >> 24) & 0xFF];
const int32_t var_sine = sine_table_i8[((phase_30 - radial_offset) >> 24) & 0xFF];
phase_30 += delta_30;
// 9960 Hz subcarrier, FM-modulated +/- 480 Hz by the 30 Hz reference tone.
const int32_t sub_inc = static_cast<int32_t>(delta_sub) + ((ref_sine * static_cast<int32_t>(delta_480)) >> 7);
phase_sub += static_cast<uint32_t>(sub_inc);
const int32_t sub_sine = sine_table_i8[(phase_sub >> 24) & 0xFF];
// Optional 1020 Hz identification tone.
int32_t id_sine = 0;
if (ident_enabled && ident_tone_active()) {
id_sine = sine_table_i8[(phase_id >> 24) & 0xFF];
phase_id += delta_1020;
}
// DSB-AM envelope (carrier kept at LO -> Q = 0).
int32_t env = carrier_level + (((var_sine * var_depth) + (sub_sine * sub_depth) + (id_sine * id_depth)) >> 7);
if (env < 0) env = 0;
if (env > 127) env = 127;
buffer.p[i] = {static_cast<int8_t>(env), 0};
}
}
void VorTxProcessor::vor_tx_config(const VorTxConfigureMessage& message) {
// Real VOR radials increase clockwise: the variable tone lags the 30 Hz
// reference by the bearing, so the offset is subtracted (see the matching
// (reference - variable) decode in proc_vor_rx). A TX->RX loopback with this
// convention still decodes a transmitted radial of N degrees as N degrees,
// and it now matches real ground-station VOR bearings.
radial_offset = static_cast<uint32_t>(static_cast<uint64_t>(message.radial_deg % 360) * phase_period / 360);
ident_enabled = message.ident_enabled;
for (size_t i = 0; i < sizeof(ident_text); ++i)
ident_text[i] = message.ident_text[i];
ident_text[sizeof(ident_text) - 1] = '\0';
build_ident_schedule();
configured = message.enabled;
}
// Render the ident text into a repeating sequence of keyed-on / keyed-off
// sample runs using the shared ITU Morse table. Timing is derived from the
// standard "dot = 1200 / wpm" relation; letters are separated by a 3-unit gap,
// words by 7 units, and a trailing gap pads each cycle to a fixed 10 s period.
void VorTxProcessor::build_ident_schedule() {
ident_segment_count = 0;
ident_index = 0;
ident_sample_counter = 0;
const uint32_t dot_samples = static_cast<uint32_t>(1200ULL * baseband_fs / (ident_wpm * 1000ULL));
uint32_t total_samples = 0;
auto push_samples = [&](bool on, uint32_t samples) {
if (ident_segment_count >= max_ident_segments) return;
ident_segments[ident_segment_count++] = {on, samples};
total_samples += samples;
};
auto push = [&](bool on, uint32_t units) {
push_samples(on, units * dot_samples);
};
bool any = false;
for (size_t n = 0; n < sizeof(ident_text) && ident_text[n]; ++n) {
char ch = ident_text[n];
if (ch >= 'a' && ch <= 'z') ch -= 32;
uint16_t code = 0;
if (ch >= '!' && ch <= '_') code = morse::morse_ITU[ch - '!'];
if (!code) {
// Space or unsupported character: word gap between symbols.
if (any) push(false, MORSE_WORD_SPACE);
continue;
}
const uint16_t code_size = code & 7;
for (uint16_t c = 0; c < code_size; ++c) {
const bool dash = ((code << c) & 0x8000) != 0;
push(true, dash ? MORSE_DASH : MORSE_DOT);
if (c + 1 < code_size)
push(false, MORSE_SYMBOL_SPACE);
}
push(false, MORSE_LETTER_SPACE);
any = true;
}
if (!any) {
// No sendable characters: disable keying entirely.
ident_segment_count = 0;
return;
}
// Pad the trailing silence so ident-start to ident-start is a full 10 s.
// If the keyed sequence is somehow longer than the period, fall back to a
// one word-space gap so repeats never run back-to-back.
const uint32_t min_gap = MORSE_WORD_SPACE * dot_samples;
const uint32_t gap = (ident_period_samples > total_samples + min_gap)
? ident_period_samples - total_samples
: min_gap;
push_samples(false, gap);
}
// Advances the keying schedule by one sample and returns whether the ident
// tone should be sounding right now. Returns false when there is nothing to
// send so the caller leaves the ident tone off.
bool VorTxProcessor::ident_tone_active() {
if (ident_segment_count == 0) return false;
if (ident_sample_counter == 0)
ident_sample_counter = ident_segments[ident_index].length;
const bool on = ident_segments[ident_index].on;
if (ident_sample_counter == 0 || --ident_sample_counter == 0) {
++ident_index;
if (ident_index >= ident_segment_count) ident_index = 0;
}
return on;
}
void VorTxProcessor::on_message(const Message* const msg) {
if (msg->id == Message::ID::VorTxConfigure) {
vor_tx_config(*reinterpret_cast<const VorTxConfigureMessage*>(msg));
}
}
int main() {
EventDispatcher event_dispatcher{std::make_unique<VorTxProcessor>()};
event_dispatcher.run();
return 0;
}
+90
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@@ -0,0 +1,90 @@
/*
* Copyright (C) 2026 PortaPack Mayhem
*
* 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; if not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __PROC_VOR_TX_H__
#define __PROC_VOR_TX_H__
#include "baseband_processor.hpp"
#include "baseband_thread.hpp"
// Generates a conventional VOR composite signal as DSB-AM (carrier at LO, Q = 0):
// - 30 Hz "variable" tone, amplitude-modulated directly (phase = transmitted radial)
// - 9960 Hz subcarrier, FM-modulated (+/- 480 Hz) by a 30 Hz "reference" tone
// - optional 1020 Hz identification tone
// The radial encoded is the phase difference between the variable and reference 30 Hz tones.
class VorTxProcessor : public BasebandProcessor {
public:
void execute(const buffer_c8_t& buffer) override;
void on_message(const Message* const msg) override;
private:
static constexpr size_t baseband_fs = 1536000;
static constexpr uint64_t phase_period = 1ULL << 32;
// Per-sample phase increments (top byte indexes the 256-entry sine table).
static constexpr uint32_t delta_30 = static_cast<uint32_t>(30ULL * phase_period / baseband_fs);
static constexpr uint32_t delta_sub = static_cast<uint32_t>(9960ULL * phase_period / baseband_fs);
static constexpr uint32_t delta_1020 = static_cast<uint32_t>(1020ULL * phase_period / baseband_fs);
static constexpr uint32_t delta_480 = static_cast<uint32_t>(480ULL * phase_period / baseband_fs);
// AM levels (int8 scale). carrier_level + sum of contributions must stay <= 127.
static constexpr int32_t carrier_level = 60;
static constexpr int32_t var_depth = 18; // ~30% of carrier
static constexpr int32_t sub_depth = 18; // ~30% of carrier
static constexpr int32_t id_depth = 6; // ~10% of carrier
// CW identifier keying. Real VOR stations key the 1020 Hz ident tone in
// Morse at ~7 words per minute, so the schedule below is expressed in
// "dot" time units and rendered to on/off sample runs at config time.
static constexpr uint32_t ident_wpm = 7;
static constexpr size_t max_ident_segments = 128;
// VOR ident is transmitted at least every 10 s; repeat the keyed identifier
// on a fixed 10 s cycle (ident start to next ident start).
static constexpr uint32_t ident_period_samples = 10 * baseband_fs;
struct IdentSegment {
bool on;
uint32_t length; // duration in samples
};
uint32_t phase_30{0};
uint32_t phase_sub{0};
uint32_t phase_id{0};
uint32_t radial_offset{0};
bool ident_enabled{true};
bool configured{false};
char ident_text[8]{};
IdentSegment ident_segments[max_ident_segments]{};
size_t ident_segment_count{0};
size_t ident_index{0};
uint32_t ident_sample_counter{0};
void vor_tx_config(const VorTxConfigureMessage& message);
void build_ident_schedule();
bool ident_tone_active();
/* NB: Threads should be the last members in the class definition. */
BasebandThread baseband_thread{baseband_fs, this, baseband::Direction::Transmit};
};
#endif /* __PROC_VOR_TX_H__ */
+8
View File
@@ -119,4 +119,12 @@ constexpr iir_biquad_config_t apt_audio_12k_lpf_2000hz_config{
{0.15505103f, 0.31010205f, 0.15505103f},
{1.00000000f, -0.6202041f, 0.24040821f}};
// scipy.signal.butter(2, 3200 / 24000.0, 'low', analog=False)
// VOR RX audio low-pass. Removes the 9960 Hz FM subcarrier (the annoying
// high-pitch whine) while passing voice and the 1020 Hz ident tone. Cascade
// two of these sections for a 4th-order roll-off (~44 dB at 9960 Hz).
constexpr iir_biquad_config_t audio_48k_lpf_3200hz_config{
{0.03357181f, 0.06714362f, 0.03357181f},
{1.00000000f, -1.41898265f, 0.55326989f}};
#endif /*__DSP_IIR_CONFIG_H__*/
+65
View File
@@ -162,6 +162,9 @@ class Message {
ToneDetectConfig = 104,
FlexTosend = 105,
EPIRBRXConfig = 106,
VorRxConfigure = 107,
VorRxStatusData = 108,
VorTxConfigure = 109,
MAX
};
@@ -1899,6 +1902,68 @@ class ToneDetectConfigureMessage : public Message {
uint32_t ctcss_freq_x10{0}; // CTCSS frequency × 10 (e.g. 1000 = 100.0 Hz); 0 = None
};
class VorRxConfigureMessage : public Message {
public:
constexpr VorRxConfigureMessage(bool enabled = true)
: Message{ID::VorRxConfigure},
enabled{enabled} {
}
bool enabled{true};
};
class VorRxStatusDataMessage : public Message {
public:
constexpr VorRxStatusDataMessage(
uint16_t phase_deg = 0,
uint16_t radial_deg = 0,
uint16_t reference_level = 0,
uint16_t variable_level = 0,
uint8_t quality = 0,
bool valid = false,
bool to_from = false)
: Message{ID::VorRxStatusData},
phase_deg{phase_deg},
radial_deg{radial_deg},
reference_level{reference_level},
variable_level{variable_level},
quality{quality},
valid{valid},
to_from{to_from} {
}
uint16_t phase_deg{0};
uint16_t radial_deg{0};
uint16_t reference_level{0};
uint16_t variable_level{0};
uint8_t quality{0};
bool valid{false};
bool to_from{false};
};
class VorTxConfigureMessage : public Message {
public:
VorTxConfigureMessage(
uint16_t radial_deg = 0,
bool ident_enabled = true,
const char* ident = "",
bool enabled = true)
: Message{ID::VorTxConfigure},
radial_deg{radial_deg},
ident_enabled{ident_enabled},
enabled{enabled} {
size_t i = 0;
for (; ident && ident[i] && i < sizeof(ident_text) - 1; ++i)
ident_text[i] = ident[i];
ident_text[i] = '\0';
}
uint16_t radial_deg{0};
bool ident_enabled{true};
bool enabled{true};
char ident_text[8]{}; // CW identifier, null-terminated (max 7 chars)
};
class FlexTosendMessage : public Message {
public:
constexpr FlexTosendMessage(
+2
View File
@@ -129,6 +129,8 @@ constexpr image_tag_t image_tag_noaaapt_rx{'P', 'N', 'O', 'A'};
constexpr image_tag_t image_tag_sstv_rx{'P', 'S', 'R', 'X'};
constexpr image_tag_t image_tag_morse{'P', 'M', 'R', 'S'};
constexpr image_tag_t image_tag_morsetx{'P', 'M', 'R', 'T'};
constexpr image_tag_t image_tag_vor_tx{'P', 'V', 'T', 'X'};
constexpr image_tag_t image_tag_vor_rx{'P', 'V', 'R', 'X'};
constexpr image_tag_t image_tag_rttyrx{'P', 'R', 'T', 'R'};
constexpr image_tag_t image_tag_rttytx{'P', 'R', 'T', 'T'};
constexpr image_tag_t image_tag_tonedetect{'P', 'T', 'N', 'E'};
+1 -1
View File
@@ -24,4 +24,4 @@
# external app address ranges below must match those in linker file "external.ld"
maximum_application_size = 32*1024
external_apps_address_start = 0xADB00000
external_apps_address_end = 0xAE090000
external_apps_address_end = 0xAE0B0000