portapack-mayhem/firmware/application/apps/capture_app.cpp

/*
 * Copyright (C) 2016 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2018 Furrtek
 *
 * This file is part of PortaPack.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include "capture_app.hpp"
#include "baseband_api.hpp"
#include "portapack.hpp"

using namespace portapack;

namespace ui {

CaptureAppView::CaptureAppView(NavigationView& nav)
    : nav_{nav} {
    freqman_set_bandwidth_option(SPEC_MODULATION, option_bandwidth);
    baseband::run_image(portapack::spi_flash::image_tag_capture);

    add_children({
        &labels,
        &rssi,
        &channel,
        &field_frequency,
        &field_frequency_step,
        &field_rf_amp,
        &field_lna,
        &field_vga,
        &option_bandwidth,
        &record_view,
        &waterfall,
    });

    field_frequency_step.set_by_value(receiver_model.frequency_step());
    field_frequency_step.on_change = [this](size_t, OptionsField::value_t v) {
        receiver_model.set_frequency_step(v);
        this->field_frequency.set_step(v);
    };

    option_bandwidth.on_change = [this](size_t, uint32_t base_rate) {
        sampling_rate = 8 * base_rate;  // Decimation by 8 done on baseband side
                                        /* base_rate is used for FFT calculation and display LCD, and also in recording writing SD Card rate. */
        /* ex. sampling_rate values, 4Mhz, when recording 500 kHz (BW) and fs 8 Mhz, when selected 1 Mhz BW ... */
        /* ex. recording 500kHz BW to .C16 file, base_rate clock 500kHz x2(I,Q) x 2 bytes (int signed) =2MB/sec rate SD Card  */
        waterfall.on_hide();

        /* Set up proper anti aliasing BPF bandwith in MAX2837 before ADC sampling according to the new added BW Options . */
        switch (sampling_rate) {  // we use the var fs (sampling_rate) , to set up BPF aprox < fs_max/2 by Nyquist theorem.

            case 0 ... 2000000:                                  // BW Captured range  (0 <= 250kHz max )  fs = 8 x 250 kHz
                anti_alias_baseband_bandwidth_filter = 1750000;  // Minimum BPF MAX2837 for all those lower BW options.
                break;

            case 4000000 ... 6000000:                            // BW capture  range (500k ... 750kHz max )  fs_max = 8 x 750kHz = 6Mhz
                                                                 //  BW 500k ... 750kHz   ,  ex. 500kHz   (fs = 8*BW =  4Mhz) , BW 600kHz (fs = 4,8Mhz) , BW  750 kHz (fs = 6Mhz)
                anti_alias_baseband_bandwidth_filter = 2500000;  // in some IC MAX2837 appear 2250000 , but both works similar.
                break;

            case 8800000:  // BW capture 1,1Mhz  fs = 8 x 1,1Mhz = 8,8Mhz . (1Mhz showed slightly higher noise background).
                anti_alias_baseband_bandwidth_filter = 3500000;
                break;

            case 14000000:  // BW capture 1,75Mhz  , fs = 8 x 1,75Mhz = 14Mhz
                            // good BPF, good matching, but LCD making flicker , refresh rate should be < 20 Hz , but reasonable picture
                anti_alias_baseband_bandwidth_filter = 5000000;
                break;

            case 16000000:  // BW capture 2Mhz  , fs = 8 x 2Mhz = 16Mhz
                            // good BPF, good matching, but LCD making flicker , refresh rate should be < 20 Hz , but reasonable picture
                anti_alias_baseband_bandwidth_filter = 6000000;
                break;

            case 20000000:  // BW capture 2,5Mhz  , fs= 8 x 2,5 Mhz = 20Mhz
                            // good BPF, good matching, but LCD making flicker , refresh rate should be < 20 Hz , but reasonable picture
                anti_alias_baseband_bandwidth_filter = 7000000;
                break;

            default:  // BW capture 2,75Mhz, fs = 8 x 2,75Mhz= 22Mhz max ADC sampling) and others.
                      //  We tested also 9Mhz FPB stightly too much noise floor, better 8Mhz
                anti_alias_baseband_bandwidth_filter = 8000000;
        }

        record_view.set_sampling_rate(sampling_rate);
        receiver_model.set_sampling_rate(sampling_rate);
        receiver_model.set_baseband_bandwidth(anti_alias_baseband_bandwidth_filter);

        waterfall.on_show();
    };

    option_bandwidth.set_selected_index(7);  // Preselected default option 500kHz.

    receiver_model.set_modulation(ReceiverModel::Mode::Capture);
    receiver_model.enable();

    record_view.on_error = [&nav](std::string message) {
        nav.display_modal("Error", message);
    };
}

CaptureAppView::~CaptureAppView() {
    // Most other apps can't handle "Capture" mode, set to something standard.
    receiver_model.set_modulation(ReceiverModel::Mode::WidebandFMAudio);
    receiver_model.disable();
    baseband::shutdown();
}

void CaptureAppView::on_hide() {
    waterfall.on_hide();
    View::on_hide();
}

void CaptureAppView::set_parent_rect(const Rect new_parent_rect) {
    View::set_parent_rect(new_parent_rect);

    ui::Rect waterfall_rect{0, header_height, new_parent_rect.width(), new_parent_rect.height() - header_height};
    waterfall.set_parent_rect(waterfall_rect);
}

void CaptureAppView::focus() {
    record_view.focus();
}

} /* namespace ui */