Adding 16 bit LFSR , to Noise Signal Generator App

This commit is contained in:
Brumi-2021 2023-05-02 17:19:23 +02:00
parent 06643df6a5
commit d5f20c45b9
3 changed files with 37 additions and 21 deletions

View File

@ -48,29 +48,30 @@ 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[9] = { const std::string shape_strings[10] = {
"CW ", "CW-no mod",
"Sine ", "Sine ",
"Triangle ", "Triangle ",
"Saw up ", "Saw up ",
"Saw down ", "Saw down ",
"Square ", "Square ",
"Noise n20Khz", "Noise 8-nx20Khz", // using 8 bits LFSR register, 6 order polynomial feedback.
"Noise n10khz", "Noise 8-nx10khz", // using 8 bits LFSR register, 7 order polynomial feedback.
"Noise n5khz " "Noise 8 -nx5khz ", // using 8 bits LFSR register, 8 order polynomial feedback.
"Noise 16-nx1khz" // using 16 bits LFSR register, 16 order polynomial feedback.
}; };
bool auto_update { false }; bool auto_update { false };
Labels labels { Labels labels {
{ { 6 * 8, 4 + 10 }, "Shape:", Color::light_grey() }, { { 3 * 8, 4 + 10 }, "Shape:", Color::light_grey() },
{ { 7 * 8, 7 * 8 }, "Tone: Hz", Color::light_grey() }, { { 6 * 8, 7 * 8 }, "Tone: Hz", Color::light_grey() },
{ { 22 * 8, 15 * 8 + 4 }, "s.", Color::light_grey() }, { { 22 * 8, 15 * 8 + 4 }, "s.", Color::light_grey() },
{ { 8 * 8, 20 * 8 }, "Modulation: FM", Color::light_grey() } { { 8 * 8, 20 * 8 }, "Modulation: FM", Color::light_grey() }
}; };
ImageOptionsField options_shape { ImageOptionsField options_shape {
{ 13 * 8, 4, 32, 32 }, { 10 * 8, 4, 32, 32 },
Color::white(), Color::white(),
Color::black(), Color::black(),
{ {
@ -82,12 +83,13 @@ private:
{ &bitmap_sig_square, 5 }, { &bitmap_sig_square, 5 },
{ &bitmap_sig_noise, 6 }, { &bitmap_sig_noise, 6 },
{ &bitmap_sig_noise, 7 }, { &bitmap_sig_noise, 7 },
{ &bitmap_sig_noise, 8 } { &bitmap_sig_noise, 8 },
{ &bitmap_sig_noise, 9 }
} }
}; };
Text text_shape { Text text_shape {
{ 18 * 8, 4 + 10, 8 * 8, 16 }, { 15 * 8, 4 + 10, 8 * 8, 16 },
"" ""
}; };
@ -98,12 +100,12 @@ private:
}; };
Button button_update { Button button_update {
{ 6 * 8, 10 * 8, 8 * 8, 3 * 8 }, { 5 * 8, 10 * 8, 8 * 8, 3 * 8 },
"Update" "Update"
}; };
Checkbox checkbox_auto { Checkbox checkbox_auto {
{ 16 * 8, 10 * 8 }, { 15 * 8, 10 * 8 },
4, 4,
"Auto" "Auto"
}; };

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@ -75,6 +75,17 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
bit = ((lfsr >> 0) ^ (lfsr >> 2) ^ (lfsr >> 3) ^ (lfsr >> 4)) & 1; bit = ((lfsr >> 0) ^ (lfsr >> 2) ^ (lfsr >> 3) ^ (lfsr >> 4)) & 1;
lfsr = (lfsr >> 1) | (bit << 7); lfsr = (lfsr >> 1) | (bit << 7);
sample = lfsr; sample = lfsr;
} else if (tone_shape == 9) { // 16 bits LFSR .taps: 16, 15, 13, 4 ;feedback polynomial: x^16 + x^15 + x^13 + x^4 + 1
// Periode 65535= 2^n-1, harmonics every < 1Khz , quite continuous .
if (counter == 0) {
bit_16 = ((lfsr_16 >> 0) ^ (lfsr_16 >> 1) ^ (lfsr_16 >> 3) ^ (lfsr_16 >> 4) ^ (lfsr_16 >> 12) & 1);
lfsr_16 = (lfsr_16 >> 1) | (bit_16 << 15);
sample = (lfsr_16 & 0x00FF);
counter++;
} else { // counter == 1 , no need to shift the register again, just use the top 8 bits.
// sample = ((lfsr_16 & 0XFF00) >> 8); // it becomes less continuous the spectrum. Better skip it .
counter = 0;
}
} }
if (tone_shape < 6) { if (tone_shape < 6) {
@ -114,8 +125,8 @@ 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 = seed_value ; // init lfsr 8 bits.
lfsr = seed_value ; lfsr_16 = seed_value_16; // init lfsr 16 bits.
configured = true; configured = true;
break; break;

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@ -44,9 +44,12 @@ private:
bool auto_off { }; bool auto_off { };
int32_t phase { 0 }, sphase { 0 }, delta { 0 }; // they may have sign . int32_t phase { 0 }, sphase { 0 }, delta { 0 }; // they may have sign .
int8_t sample { 0 }, re { 0 }, im { 0 }; // they may have sign . int8_t sample { 0 }, re { 0 }, im { 0 }; // they may have sign .
uint8_t seed_value = {0x56}; // seed : any nonzero start state will work. uint8_t seed_value = {0x56}; // seed 8 bits lfsr : any nonzero start state will work.
uint16_t seed_value_16 = {0xACE1}; // seed 16 bits lfsr : any nonzero start state will work.
uint8_t lfsr { }, bit { }; // bit must be 8-bit to allow bit<<7 later in the code */ uint8_t lfsr { }, bit { }; // bit must be 8-bit to allow bit<<7 later in the code */
uint16_t lfsr_16 { }, bit_16 { }; // bit must be 8-bit to allow bit<<7 later in the code */
uint8_t counter {0};
TXProgressMessage txprogress_message { }; TXProgressMessage txprogress_message { };
}; };