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Solving Noise generation in Signal gen App

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This commit is contained in:
Brumi-2021 2023-04-30 18:03:40 +02:00
parent cb93f2636e
commit ee53b28e60
3 changed files with 42 additions and 26 deletions
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10
firmware/application/apps/ui_siggen.hpp
View File

@ -48,14 +48,16 @@ private:
void update_tone(); void update_tone();
void on_tx_progress(const uint32_t progress, const bool done); void on_tx_progress(const uint32_t progress, const bool done);
const std::string shape_strings[7] = { const std::string shape_strings[9] = {
"CW ", "CW ",
"Sine ", "Sine ",
"Triangle ", "Triangle ",
"Saw up ", "Saw up ",
"Saw down ", "Saw down ",
"Square ", "Square ",
"Noise" "Noise n20Khz",
"Noise n10khz",
"Noise n5khz "
}; };
bool auto_update { false }; bool auto_update { false };
@ -78,7 +80,9 @@ private:
{ &bitmap_sig_saw_up, 3 }, { &bitmap_sig_saw_up, 3 },
{ &bitmap_sig_saw_down, 4 }, { &bitmap_sig_saw_down, 4 },
{ &bitmap_sig_square, 5 }, { &bitmap_sig_square, 5 },
{ &bitmap_sig_noise, 6 } { &bitmap_sig_noise, 6 },
{ &bitmap_sig_noise, 7 },
{ &bitmap_sig_noise, 8 }
} }
}; };

29
firmware/baseband/proc_siggen.cpp
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@ -49,7 +49,7 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
// Sine // Sine
sample = (sine_table_i8[(tone_phase & 0xFF000000) >> 24]); sample = (sine_table_i8[(tone_phase & 0xFF000000) >> 24]);
} else if (tone_shape == 2) { } else if (tone_shape == 2) {
// Tri // Triangle
int8_t a = (tone_phase & 0xFF000000) >> 24; int8_t a = (tone_phase & 0xFF000000) >> 24;
sample = (a & 0x80) ? ((a << 1) ^ 0xFF) - 0x80 : (a << 1) + 0x80; sample = (a & 0x80) ? ((a << 1) ^ 0xFF) - 0x80 : (a << 1) + 0x80;
} else if (tone_shape == 3) { } else if (tone_shape == 3) {
@ -61,17 +61,27 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
} else if (tone_shape == 5) { } else if (tone_shape == 5) {
// Square // Square
sample = (((tone_phase & 0xFF000000) >> 24) & 0x80) ? 127 : -128; sample = (((tone_phase & 0xFF000000) >> 24) & 0x80) ? 127 : -128;
} else if (tone_shape == 6) { } else if (tone_shape == 6) { // taps: 6 5; feedback polynomial: x^6 + x^5 + 1 , Periode 63 = 2^n-1,it generates armonincs n x 20Khz
// Noise // White Noise generator, pseudo random noise generator, 8 bits linear-feedback shift register (LFSR) algorithm, variant Fibonacci.
sample = (lfsr & 0xFF000000) >> 24; // https://en.wikipedia.org/wiki/Linear-feedback_shift_register
feedback = ((lfsr >> 31) ^ (lfsr >> 29) ^ (lfsr >> 15) ^ (lfsr >> 11)) & 1; bit = ((lfsr >> 2) ^ (lfsr >> 3)) & 1;
lfsr = (lfsr << 1) | feedback; lfsr = (lfsr >> 1) | (bit << 7);
if (!lfsr) lfsr = 0x1337; // Shouldn't do this :( sample = lfsr;
} else if (tone_shape == 7) { // taps: 7 6; feedback polynomial: x^7 + x^6 + 1 , Periode 127 = 2^n-1,it generates armonincs n x 10Khz
bit = ((lfsr >> 1) ^ (lfsr >> 2)) & 1;
lfsr = (lfsr >> 1) | (bit << 7);
sample = lfsr;
} else if (tone_shape == 8) { //taps:8,6,5,4;feedback polynomial: x^8 + x^6 + x^5 + x^4 + 1,Periode 255= 2^n-1, armonics n x 5khz
bit = ((lfsr >> 0) ^ (lfsr >> 2) ^ (lfsr >> 3) ^ (lfsr >> 4)) & 1;
lfsr = (lfsr >> 1) | (bit << 7);
sample = lfsr;
} }
if (tone_shape < 6) {
tone_phase += tone_delta; tone_phase += tone_delta;
}
// Do FM // Do FM modulation
delta = sample * fm_delta; delta = sample * fm_delta;
phase += delta; phase += delta;
@ -104,7 +114,8 @@ void SigGenProcessor::on_message(const Message* const msg) {
fm_delta = message.bw * (0xFFFFFFULL / 1536000); fm_delta = message.bw * (0xFFFFFFULL / 1536000);
tone_shape = message.shape; tone_shape = message.shape;
lfsr = 0x54DF0119; // lfsr = 0x54DF0119;
lfsr = seed_value ;
configured = true; configured = true;
break; break;

11
firmware/baseband/proc_siggen.hpp
View File

@ -38,13 +38,14 @@ private:
BasebandThread baseband_thread { 1536000, this, NORMALPRIO + 20, baseband::Direction::Transmit }; BasebandThread baseband_thread { 1536000, this, NORMALPRIO + 20, baseband::Direction::Transmit };
uint32_t tone_delta { 0 }, fm_delta { }; uint32_t tone_delta { 0 }, fm_delta { },tone_phase { 0 };
uint32_t lfsr { }, feedback { }, tone_shape { }; uint8_t tone_shape { };
uint32_t sample_count { 0 }; uint32_t sample_count { 0 };
bool auto_off { }; bool auto_off { };
uint32_t tone_phase { 0 }, phase { 0 }, delta { 0 }, sphase { 0 }; int32_t phase { 0 }, sphase { 0 }, delta { 0 }; // they may have sign .
int8_t sample { 0 }; int8_t sample { 0 }, re { 0 }, im { 0 }; // they may have sign .
int8_t re { 0 }, im { 0 }; uint8_t seed_value = {0x56}; // seed : any nonzero start state will work.
uint8_t lfsr { }, bit { }; // bit must be 8-bit to allow bit<<7 later in the code */
TXProgressMessage txprogress_message { }; TXProgressMessage txprogress_message { };
}; };