Improved sensitivity/selectivity Weather App (#1628)

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Brumi-2021 2023-12-08 21:33:48 +01:00 committed by GitHub
parent a474bf8fe3
commit 60d95447fb
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3 changed files with 40 additions and 8 deletions

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@ -100,8 +100,8 @@ class WeatherView : public View {
NavigationView& nav_;
RxRadioState radio_state_{
433'920'000 /* frequency */,
1'750'000 /* bandwidth */,
2'000'000 /* sampling rate */,
2'500'000 /* bandwidth max283x*/,
4'000'000 /* sampling rate */,
ReceiverModel::Mode::AMAudio};
app_settings::SettingsManager settings_{
"rx_weather",

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@ -27,10 +27,22 @@
void WeatherProcessor::execute(const buffer_c8_t& buffer) {
if (!configured) return;
for (size_t i = 0; i < buffer.count; i++) {
int8_t re = buffer.p[i].real();
int8_t im = buffer.p[i].imag();
// SR = 4Mhz , and we are decimating by /8 in total , decim1_out clock 4Mhz /8= 500khz samples/sec.
// buffer has 2048 complex i8 I,Q signed samples
// decim0 out: 2048/4 = 512 complex i16 I,Q signed samples
// decim1 out: 512/2 = 256 complex i16 I,Q signed samples
// Regarding Filters, we are re-using existing FIR filters, @4Mhz, FIR decim1 ilter, BW =+-220Khz (at -3dB's). BW = 440kHZ.
const auto decim_0_out = decim_0.execute(buffer, dst_buffer); // Input:2048 complex/4 (decim factor) = 512_output complex (1024 I/Q samples)
const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer); // Input:512 complex/2 (decim factor) = 256_output complex ( 512 I/Q samples)
for (size_t i = 0; i < decim_1_out.count; i++) {
int16_t re = decim_1_out.p[i].real();
int16_t im = decim_1_out.p[i].imag();
uint32_t mag = ((uint32_t)re * (uint32_t)re) + ((uint32_t)im * (uint32_t)im);
mag = (mag >> 12); // Decim samples are calculated with saturated gain . (we could also reduce that sat. param at configure time)
bool meashl = (mag > threshold);
tm += mag;
if (meashl == currentHiLow && currentDuration < 10'000'000) // allow pass 'end' signal
@ -42,7 +54,8 @@ void WeatherProcessor::execute(const buffer_c8_t& buffer) {
currentHiLow = meashl;
}
}
cnt += buffer.count;
cnt += decim_1_out.count; // TODO , check if it is necessary that xdecim factor.
if (cnt > 30'000) {
threshold = (tm / cnt) / 2;
cnt = 0;
@ -58,6 +71,12 @@ void WeatherProcessor::on_message(const Message* const message) {
}
void WeatherProcessor::configure(const WeatherRxConfigureMessage& message) {
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;
decim_0.configure(taps_200k_wfm_decim_0.taps);
decim_1.configure(taps_200k_wfm_decim_1.taps);
(void)message;
configured = true;
}

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@ -30,6 +30,7 @@
#include "baseband_thread.hpp"
#include "rssi_thread.hpp"
#include "message.hpp"
#include "dsp_decimate.hpp"
#include "fprotos/weatherprotos.hpp"
@ -39,8 +40,20 @@ class WeatherProcessor : public BasebandProcessor {
void on_message(const Message* const message) override;
private:
static constexpr uint32_t usperTick = 500; // we nees ms to has to divide by 1000
static constexpr size_t baseband_fs = 1'750'000;
static constexpr size_t baseband_fs = 4'000'000; // it works, I think we need to write that master clock in the baseband_threat , even later we decimate it.
static constexpr uint32_t usperTick = 500 * 8; // In current sw , we do not scale it due to clock. We scaled it due to less array buffer sampes due to /8 decimation.
// TODO , Pending to investigate , why ticks are not proportional to the SR clock, 500 nseg (2Mhz) , 250 nseg (4Mhz) ??? ;previous comment : "we nees ms to has to divide by 1000"
/* Array Buffer aux. used in decim0 and decim1 IQ c16 signed data ; (decim0 defines the max length of the array) */
std::array<complex16_t, 512> dst{}; // decim0 /4 , 2048/4 = 512 complex I,Q
const buffer_c16_t dst_buffer{
dst.data(),
dst.size()};
/* Decimates */
dsp::decimate::FIRC8xR16x24FS4Decim4 decim_0{};
dsp::decimate::FIRC16xR16x16Decim2 decim_1{};
uint32_t currentDuration = 0;
uint32_t threshold = 0x0630; // will overwrite after the first iteration
bool currentHiLow = false;