Added "RESOLUTION" parameter

Discord User jteich did some investigation (Thanks!) and helped me understanding this rather obscure parameter:

Internally, is called "TRIGGER", and is passed into the baseband when configuring the desired spectrum sample rate.

Please forgive me in advance if this explanation is not 100% correct. It's only my interpretation, based on my own observation and jteich's comments over Discord chat.

This trigger parameter apparently determines the amount of data over time used for calculating the signal's power inside each specttrum's bin, before considering it "done".

In short, if you lower this resolution value then the cascade will tend to be rendered a bit faster, while kind of blind to tiny signals.

On the other hand, a bigger value will help rendering and distinguishing different signals on the cascade.

Too big a value can easily clutter up the cascade. But then it may be a "blessing" when inspecting higher freuqencies -where hackrf is more deaf"

The default value of 32 is quite decent. But then, now you can experiment with it. Cheers
This commit is contained in:
euquiq 2020-10-26 23:43:35 -03:00
parent 210ec9dd1b
commit 13ce56f7bf
2 changed files with 23 additions and 6 deletions

View File

@ -100,7 +100,7 @@ void GlassView::on_channel_spectrum(const ChannelSpectrum &spectrum)
}
if (pixel_index)
f_center += SEARCH_SLICE_WIDTH; //Move into the next bandwidth slice
f_center += SEARCH_SLICE_WIDTH; //Move into the next bandwidth slice NOTE: spectrum.sampling_rate = SEARCH_SLICE_WIDTH
else
f_center = f_center_ini; //Start a new sweep
@ -153,7 +153,7 @@ void GlassView::on_range_changed()
max_power = 0;
bins_Hz_size = 0; //reset amount of Hz filled up by pixels
baseband::set_spectrum(SEARCH_SLICE_WIDTH, 31); // Trigger was 31. Need to understand this parameter.
baseband::set_spectrum(SEARCH_SLICE_WIDTH, field_trigger.value());
receiver_model.set_tuning_frequency(f_center_ini); //tune rx for this slice
}
@ -184,7 +184,8 @@ GlassView::GlassView(
&field_rf_amp,
&range_presets,
&field_marker,
&text_marker_pm
&text_marker_pm,
&field_trigger
});
load_Presets(); //Load available presets from TXT files (or default)
@ -237,8 +238,16 @@ GlassView::GlassView(
nav_.push<AnalogAudioView>(); //Jump into audio view
};
field_trigger.set_value(32); //Defaults to 32, as normal triggering resolution
field_trigger.on_change = [this](int32_t v) {
baseband::set_spectrum(SEARCH_SLICE_WIDTH, v);
};
display.scroll_set_area( 109, 319);
baseband::set_spectrum(SEARCH_SLICE_WIDTH, 31); // Trigger was 31. Need to understand this parameter.
baseband::set_spectrum(SEARCH_SLICE_WIDTH, field_trigger.value()); //trigger:
// Discord User jteich: WidebandSpectrum::on_message to set the trigger value. In WidebandSpectrum::execute ,
// it keeps adding the output of the fft to the buffer until "trigger" number of calls are made,
//at which time it pushes the buffer up with channel_spectrum.feed
on_range_changed();

View File

@ -89,8 +89,8 @@
{{0, 0}, "MIN: MAX: LNA VGA ", Color::light_grey()},
{{0, 1 * 16}, " RANGE: FILTER: AMP:", Color::light_grey()},
{{0, 2 * 16}, "PRESET:", Color::light_grey()},
{{0, 3 * 16}, "MARKER: MHz +/- MHz", Color::light_grey()}
{{0, 3 * 16}, "MARKER: MHz +/- MHz", Color::light_grey()},
{{0, 4 * 16}, "RESOLUTION: (fft trigger)", Color::light_grey()}
};
NumberField field_frequency_min {
@ -151,6 +151,14 @@
{20 * 8, 3 * 16, 2 * 8, 16},
""};
NumberField field_trigger{
{11 * 8, 4 * 16},
3,
{2, 128},
2,
' '};
MessageHandlerRegistration message_handler_spectrum_config {
Message::ID::ChannelSpectrumConfig,
[this](const Message* const p) {