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Added different modulations in signal generator
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Added DSB, AM 100% mod index and AM 50% mod index. Changed UI.
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@daviderud
daviderud committed Jan 25, 2025
1 parent c413f92 commit 4ed0875
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Showing 4 changed files with 134 additions and 83 deletions.
35 changes: 31 additions & 4 deletions firmware/application/apps/ui_siggen.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -44,9 +44,9 @@ SigGenView::~SigGenView() {

void SigGenView::update_config() {
if (checkbox_stop.value())
baseband::set_siggen_config(transmitter_model.channel_bandwidth(), options_shape.selected_index_value(), field_stop.value());
baseband::set_siggen_config(transmitter_model.channel_bandwidth(), (options_mod.selected_index_value() << 4) + options_shape.selected_index_value(), field_stop.value());
else
baseband::set_siggen_config(transmitter_model.channel_bandwidth(), options_shape.selected_index_value(), 0);
baseband::set_siggen_config(transmitter_model.channel_bandwidth(), (options_mod.selected_index_value() << 4) + options_shape.selected_index_value(), 0);
}

void SigGenView::update_tone() {
Expand Down Expand Up @@ -78,6 +78,7 @@ SigGenView::SigGenView(
baseband::run_image(portapack::spi_flash::image_tag_siggen);

add_children({&labels,
&options_mod,
&options_shape,
&text_shape,
&symfield_tone,
Expand All @@ -87,22 +88,48 @@ SigGenView::SigGenView(
&field_stop,
&tx_view});

symfield_tone.hidden(1); // At first launch , by default we are in CW Shape has NO MOD , we are not using Tone modulation.
symfield_tone.hidden(1); // At first launch , by default we are in CW: Shape ignored, we are not using Tone modulation.
options_shape.hidden(1);
text_shape.hidden(1);
symfield_tone.set_value(1000); // Default: 1000 Hz
options_shape.on_change = [this](size_t, OptionsField::value_t v) {
text_shape.set(shape_strings[v]);
if (auto_update)
update_config();
if ((v == 0) || (v == 6)) { // In Shapes Options (CW & Pseudo Random Noise) we are not using Tone modulation freq.

if (v == 5) { // In Shape Pseudo Random Noise we are not using Tone modulation freq.
symfield_tone.hidden(1);
} else {
symfield_tone.hidden(0);
}

set_dirty();
};
options_shape.set_selected_index(0);
text_shape.set(shape_strings[0]);

options_mod.on_change = [this](size_t, OptionsField::value_t v) {
if (auto_update)
update_config();

if (v == 0) { // In Modulation Options CW we are not using Tone modulation freq.
symfield_tone.hidden(1);
} else {
symfield_tone.hidden(0);
}

if ((v == 0) || (v == 2) || (v == 3)) { // In Modulation Options CW, QPSK, BPSK we are not using Shapes.
options_shape.hidden(1);
text_shape.hidden(1);
} else {
options_shape.hidden(0);
text_shape.hidden(0);
}

set_dirty();
};
options_mod.set_selected_index(0);

field_stop.set_value(1);

symfield_tone.set_value(1000); // Default: 1000 Hz
Expand Down
65 changes: 35 additions & 30 deletions firmware/application/apps/ui_siggen.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -58,68 +58,73 @@ class SigGenView : public View {
app_settings::SettingsManager settings_{
"tx_siggen", app_settings::Mode::TX};

const std::string shape_strings[9] = {
"CW (No mod.) ",
"Sine mod. FM",
"Triangle mod.FM", // max 15 character text space.
"Saw up mod. FM",
"Saw down mod.FM",
"Square mod. FM",
"Pseudo Noise FM", // using 16 bits LFSR register, 16 order polynomial feedback.
"BPSK 0,1,0,1...",
"QPSK 00-01-10.."};
const std::string shape_strings[6] = { // max 15 character text space.
"Sine",
"Triangle",
"Saw up",
"Saw down",
"Square",
"Pseudo Noise"};

bool auto_update{false};

Labels labels{
{{3 * 8, 4 + 10}, "Shape:", Theme::getInstance()->fg_light->foreground},
{{6 * 8, 7 * 8}, "Tone: Hz", Theme::getInstance()->fg_light->foreground},
{{22 * 8, 15 * 8 + 4}, "s.", Theme::getInstance()->fg_light->foreground},
{{8 * 8, 20 * 8}, "Modulation: FM", Theme::getInstance()->fg_light->foreground}};
{{3 * 8, 2 * 8}, "Modulation:", Theme::getInstance()->fg_light->foreground},
{{3 * 8, 3 * 8 + 8 + 10}, "Shape:", Theme::getInstance()->fg_light->foreground},
{{6 * 8, 2 * 8 + 7 * 8}, "Tone: Hz", Theme::getInstance()->fg_light->foreground},
{{22 * 8, 2 * 8 + 15 * 8 + 4}, "s.", Theme::getInstance()->fg_light->foreground}};

ImageOptionsField options_shape{
{10 * 8, 4, 32, 32},
{10 * 8, 3 * 8 + 8, 32, 32},
Theme::getInstance()->bg_darkest->foreground,
Theme::getInstance()->bg_darkest->background,
{{&bitmap_sig_cw, 0},
{&bitmap_sig_sine, 1},
{&bitmap_sig_tri, 2},
{&bitmap_sig_saw_up, 3},
{&bitmap_sig_saw_down, 4},
{&bitmap_sig_square, 5},
{&bitmap_sig_noise, 6},
{&bitmap_sig_noise, 7}, // Pending to add a correct BPSK icon.
{&bitmap_sig_noise, 8}}}; // Pending to add a correct QPSK icon.
{{&bitmap_sig_sine, 0},
{&bitmap_sig_tri, 1},
{&bitmap_sig_saw_up, 2},
{&bitmap_sig_saw_down, 3},
{&bitmap_sig_square, 4},
{&bitmap_sig_noise, 5}}};

Text text_shape{
{15 * 8, 4 + 10, 15 * 8, 16},
{15 * 8, 3 * 8 + 8 + 10, 15 * 8, 16},
""};

SymField symfield_tone{
{12 * 8, 7 * 8},
{12 * 8, 2 * 8 + 7 * 8},
5};

Button button_update{
{5 * 8, 10 * 8, 8 * 8, 3 * 8},
{5 * 8, 2 * 8 + 10 * 8, 8 * 8, 3 * 8},
"Update"};

Checkbox checkbox_auto{
{15 * 8, 10 * 8},
{15 * 8, 2 * 8 + 10 * 8},
4,
"Auto"};

Checkbox checkbox_stop{
{5 * 8, 15 * 8},
{5 * 8, 2 * 8 + 15 * 8},
10,
"Stop after"};

NumberField field_stop{
{20 * 8, 15 * 8 + 4},
{20 * 8, 2 * 8 + 15 * 8 + 4},
2,
{1, 99},
1,
' '};

OptionsField options_mod{
{15 * 8, 2 * 8},
12,
{{"CW (No mod.)", 0},
{"FM", 1},
{"BPSK", 2},
{"QPSK", 3},
{"DSB", 4},
{"AM 100% dep.", 5},
{"AM 50% depth", 6}}};

TransmitterView tx_view{
16 * 16,
10000,
Expand Down
115 changes: 67 additions & 48 deletions firmware/baseband/proc_siggen.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -38,28 +38,67 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
} else
sample_count--;

if (tone_shape == 0) {
if (modulation == 0) {
// CW
re = 127; // max. signed 8 bits value . (-128 ...+127), max. amplitude , static phasor at 0º
im = 0;
} else {
if (tone_shape == 1) {
} else if (modulation == 2) {
// Digital BPSK consecutive 0,1,0,...continuous cycle, 1 bit/symbol, at rate of 2 symbols / Freq Tone Periode... without any Pulse shape at the moment .
re = (((tone_phase & 0xFF000000) >> 24) & 0x80) ? 127 : -128; // Sending 2 bits by Periode T of the GUI tone, alternative static phasor to 0, -180º , 0º
im = 0;
tone_phase += tone_delta; // In BPSK-QSPK we are using to calculate each 1/4 of the periode.
} else if (modulation == 3) {
// Digital QPSK consecutive 00, 01, 10, 11,00, ...continuous cycle ,2 bits/symbol, at rate of 4 symbols / Freq Tone Periode. not random., without any Pulse shape at the moment .

switch (((tone_phase & 0xFF000000) >> 24)) {
case 0 ... 63: // equivalent to 1/4 of total 360º degrees.
/* "00" */
re = (sine_table_i8[32]); // we are sending symbol-phasor 45º during 1/4 of the total periode
im = (sine_table_i8[32 + 64]); // 32 index = rounded (45º/360º * 255 total sin table steps) = 31,875
break;

case 64 ... 127:
/* "01" */
re = (sine_table_i8[96]); // symbol-phasor 135º
im = (sine_table_i8[96 + 64]); // 96 index = 32 + 256/4
break;
break;

case 128 ... 191:
/* "10" */
re = (sine_table_i8[159]); // symbol-phasor 225º
im = (sine_table_i8[159 + 64]); // 159 rounded index = 96 + 256/4 = 159.3
break;

case 192 ... 255:
/* "11" */
re = (sine_table_i8[223]); // symbol-phasor 315º ; 223 rounded index = (315/360) * 255 =223.125
im = (sine_table_i8[((223 + 64) & 0xFF)]); // Max index 255, circular periodic conversion.
break;

default:
break;
}
tone_phase += tone_delta; // In BPSK-QSPK we are using to calculate each 1/4 of the periode.

} else { // Other modulations: FM, DSB, AM
if (tone_shape == 0) {
// Sine
sample = (sine_table_i8[(tone_phase & 0xFF000000) >> 24]);
} else if (tone_shape == 2) {
} else if (tone_shape == 1) {
// Triangle
int8_t a = (tone_phase & 0xFF000000) >> 24;
sample = (a & 0x80) ? ((a << 1) ^ 0xFF) - 0x80 : (a << 1) + 0x80;
} else if (tone_shape == 3) {
} else if (tone_shape == 2) {
// Saw up
sample = ((tone_phase & 0xFF000000) >> 24);
} else if (tone_shape == 4) {
} else if (tone_shape == 3) {
// Saw down
sample = ((tone_phase & 0xFF000000) >> 24) ^ 0xFF;
} else if (tone_shape == 5) {
} else if (tone_shape == 4) {
// Square
sample = (((tone_phase & 0xFF000000) >> 24) & 0x80) ? 127 : -128;
} else if (tone_shape == 6) {
} else if (tone_shape == 5) {
// Noise generator, pseudo random noise generator, 16 bits linear-feedback shift register (LFSR) algorithm, variant Fibonacci.
// https://en.wikipedia.org/wiki/Linear-feedback_shift_register
// 16 bits LFSR .taps: 16, 15, 13, 4 ;feedback polynomial: x^16 + x^15 + x^13 + x^4 + 1
Expand All @@ -79,49 +118,13 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
if (counter == 15) {
counter = 0;
}
} else if (tone_shape == 7) {
// Digital BPSK consecutive 0,1,0,...continuous cycle, 1 bit/symbol, at rate of 2 symbols / Freq Tone Periode... without any Pulse shape at the moment .
re = (((tone_phase & 0xFF000000) >> 24) & 0x80) ? 127 : -128; // Sending 2 bits by Periode T of the GUI tone, alternative static phasor to 0, -180º , 0º
im = 0;
} else if (tone_shape == 8) {
// Digital QPSK consecutive 00, 01, 10, 11,00, ...continuous cycle ,2 bits/symbol, at rate of 4 symbols / Freq Tone Periode. not random., without any Pulse shape at the moment .

switch (((tone_phase & 0xFF000000) >> 24)) {
case 0 ... 63: // equivalent to 1/4 of total 360º degrees.
/* "00" */
re = (sine_table_i8[32]); // we are sending symbol-phasor 45º during 1/4 of the total periode
im = (sine_table_i8[32 + 64]); // 32 index = rounded (45º/360º * 255 total sin table steps) = 31,875
break;

case 64 ... 127:
/* "01" */
re = (sine_table_i8[96]); // symbol-phasor 135º
im = (sine_table_i8[96 + 64]); // 96 index = 32 + 256/4
break;
break;

case 128 ... 191:
/* "10" */
re = (sine_table_i8[159]); // symbol-phasor 225º
im = (sine_table_i8[159 + 64]); // 159 rounded index = 96 + 256/4 = 159.3
break;

case 192 ... 255:
/* "11" */
re = (sine_table_i8[223]); // symbol-phasor 315º ; 223 rounded index = (315/360) * 255 =223.125
im = (sine_table_i8[((223 + 64) & 0xFF)]); // Max index 255, circular periodic conversion.
break;

default:
break;
}
}

if (tone_shape != 6) { //(all except Pseudo Random White Noise). We are in (1):periodic signals or (2):BPSK/QPSK , in both cases ,we need Tone updated acum sum phases to modulate in FM / or control phasor phase (BPSK & QPSK.)
tone_phase += tone_delta; // In periodic signals(Sine/triangle/square) we are using to FM mod. in BPSK-QSPK we are using to calculate each 1/4 of the periode.
if (tone_shape != 5) { // All periodic except Pseudo Random White Noise.
tone_phase += tone_delta; // In periodic signals we are using phase to generate the tone to be modulated.
}

if (tone_shape < 7) { // All Option shape signals except BPSK(7) & QPSK(8) we are modulating in FM. (Those two has phase shift modulation XPSK , not FM )
if (modulation == 1) {
// Do FM modulation
delta = sample * fm_delta;

Expand All @@ -130,6 +133,21 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {

re = (sine_table_i8[(sphase & 0xFF000000) >> 24]); // sin LUT is not dealing with decimals , output range [-128 ,...127]
im = (sine_table_i8[(phase & 0xFF000000) >> 24]);

} else if (modulation == 4) {
// Do Double Side Band modulation
re = sample;
im = 0;

} else if (modulation == 5) {
// Do AM modulation (100% mod index)
re = (127 >> 1) + (sample >> 1);
im = 0;

} else if (modulation == 6) {
// Do AM modulation (50% mod index)
re = 95 + (sample >> 2);
im = 0;
}
}

Expand All @@ -154,7 +172,8 @@ void SigGenProcessor::on_message(const Message* const msg) {
auto_off = false;

fm_delta = message.bw * (0xFFFFFFULL / 1536000);
tone_shape = message.shape;
tone_shape = message.shape & 0xF;
modulation = (message.shape & 0xF0) >> 4;

// lfsr = seed_value ; // Finally not used , init lfsr 8 bits.
lfsr_16 = seed_value_16; // init lfsr 16 bits.
Expand Down
2 changes: 1 addition & 1 deletion firmware/baseband/proc_siggen.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,7 @@ class SigGenProcessor : public BasebandProcessor {
bool configured{false};

uint32_t tone_delta{0}, fm_delta{}, tone_phase{0};
uint8_t tone_shape{};
uint8_t tone_shape{}, modulation{};
uint32_t sample_count{0};
bool auto_off{};
int32_t phase{0}, sphase{0}, delta{0}; // they may have sign in the pseudo random sample generation.
Expand Down

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