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

/*
 * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2017 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 "ui_keyfob.hpp"

#include "baseband_api.hpp"
#include "string_format.hpp"

using namespace portapack;

namespace ui {

uint8_t KeyfobView::subaru_get_checksum() {
    uint8_t checksum = 0;

    for (size_t i = 0; i < 9; i++) {
        checksum ^= (frame[i] & 0x0F);  // 00 11 22 33 44 55 66 77 88 9-
        checksum ^= ((frame[i] >> 4) & 0x0F);
    }

    checksum ^= ((frame[9] >> 4) & 0x0F);
    checksum++;
    checksum &= 0x0F;

    return checksum;
}

bool KeyfobView::subaru_is_valid() {
    if (frame[0] != 0x55)
        return false;

    if (subaru_get_checksum() != (frame[9] & 0x0F))
        return false;

    return true;
}

uint16_t KeyfobView::subaru_get_code() {
    // 77777777 88888888 9999
    return (frame[7] << 12) | (frame[8] << 4) | (frame[9] >> 4);
}

void KeyfobView::subaru_set_code(const uint16_t code) {
    frame[7] = (code >> 12) & 0xFF;
    frame[8] = (code >> 4) & 0xFF;
    frame[9] &= 0x0F;
    frame[9] |= (code & 0x0F) << 4;
}

int32_t KeyfobView::subaru_get_command() {
    uint32_t command_a = frame[5] & 0x0F;
    uint32_t command_b = frame[6] & 0x0F;

    if (command_a != command_b)
        return -1;

    return command_a;
}

void KeyfobView::subaru_set_command(const uint32_t command) {
    frame[5] &= 0xF0;
    frame[5] |= command;
    frame[6] &= 0xF0;
    frame[6] |= command;
}

void KeyfobView::generate_payload(size_t& bitstream_length) {
    for (size_t i = 0; i < (10 * 8); i++) {
        if (frame[i >> 3] & (1 << (7 - (i & 7))))
            bitstream_append(bitstream_length, 2, 0b10);
        else
            bitstream_append(bitstream_length, 2, 0b01);
    }
}

size_t KeyfobView::generate_frame() {
    size_t bitstream_length = 0;
    uint64_t payload;

    // Symfield word to frame
    payload = field_payload_a.value_hex_u64();
    for (size_t i = 0; i < 5; i++) {
        frame[4 - i] = payload & 0xFF;
        payload >>= 8;
    }
    payload = field_payload_b.value_hex_u64();
    for (size_t i = 0; i < 5; i++) {
        frame[9 - i] = payload & 0xFF;
        payload >>= 8;
    }

    // Recompute checksum
    frame[9] = (frame[9] & 0xF0) | subaru_get_checksum();
    update_symfields();

    // Preamble: 128x 01
    for (size_t i = 0; i < 128; i++)
        bitstream_append(bitstream_length, 2, 0b01);

    // Space: 4x 0
    bitstream_append(bitstream_length, 4, 0b0000);

    // Payload
    generate_payload(bitstream_length);

    // Space: 8x 0
    bitstream_append(bitstream_length, 8, 0b00000000);

    // Payload again
    generate_payload(bitstream_length);

    return bitstream_length;
}

void KeyfobView::focus() {
    options_make.focus();
}

KeyfobView::~KeyfobView() {
    // save app settings
    settings.save("tx_keyfob", &app_settings);

    transmitter_model.disable();
    baseband::shutdown();
}

void KeyfobView::update_progress(const uint32_t progress) {
    text_status.set("Repeat #" + to_string_dec_uint(progress));
}

void KeyfobView::on_tx_progress(const uint32_t progress, const bool done) {
    if (!done) {
        // Repeating...
        update_progress(progress + 1);
        progressbar.set_value(progress);
    } else {
        transmitter_model.disable();
        text_status.set("Done");
        progressbar.set_value(0);
        tx_view.set_transmitting(false);
    }
}

void KeyfobView::on_make_change(size_t index) {
    (void)index;
}

// DEBUG
void KeyfobView::update_symfields() {
    for (size_t i = 0; i < 5; i++) {
        field_payload_a.set_sym(i << 1, frame[i] >> 4);
        field_payload_a.set_sym((i << 1) + 1, frame[i] & 0x0F);
    }
    for (size_t i = 0; i < 5; i++) {
        field_payload_b.set_sym(i << 1, frame[5 + i] >> 4);
        field_payload_b.set_sym((i << 1) + 1, frame[5 + i] & 0x0F);
    }
}

void KeyfobView::on_command_change(uint32_t value) {
    subaru_set_command(value);
    update_symfields();
}

void KeyfobView::start_tx() {
    progressbar.set_max(repeats - 1);

    update_progress(1);

    size_t bitstream_length = generate_frame();

    transmitter_model.enable();

    baseband::set_ook_data(
        bitstream_length,
        subaru_samples_per_bit,
        repeats,
        200  // Pause symbols
    );
}

KeyfobView::KeyfobView(
    NavigationView& nav)
    : nav_{nav} {
    baseband::run_image(portapack::spi_flash::image_tag_ook);

    add_children({&labels,
                  &options_make,
                  &options_command,
                  &field_payload_a,
                  &field_payload_b,
                  &text_status,
                  &progressbar,
                  &tx_view});

    // load app settings
    auto rc = settings.load("tx_keyfob", &app_settings);
    if (rc == SETTINGS_OK) {
        transmitter_model.set_rf_amp(app_settings.tx_amp);
        transmitter_model.set_tx_gain(app_settings.tx_gain);
    }

    frame[0] = 0x55;
    update_symfields();

    options_make.on_change = [this](size_t index, int32_t) {
        on_make_change(index);
    };

    options_command.on_change = [this](size_t, int32_t value) {
        on_command_change(value);
    };

    options_make.set_selected_index(0);

    transmitter_model.set_target_frequency(433920000);  // Fixed 433.92MHz

    tx_view.on_edit_frequency = [this, &nav]() {
        auto new_view = nav.push<FrequencyKeypadView>(transmitter_model.target_frequency());
        new_view->on_changed = [this](rf::Frequency f) {
            transmitter_model.set_target_frequency(f);
        };
    };

    tx_view.on_start = [this]() {
        start_tx();
        tx_view.set_transmitting(true);
    };

    tx_view.on_stop = [this]() {
        tx_view.set_transmitting(false);
    };
}

} /* namespace ui */