portapack-mayhem/firmware/application/tuning.cpp
2015-07-08 08:39:24 -07:00

101 lines
3.1 KiB
C++

/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
*
* 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 "ch.h"
#include "tuning.hpp"
#include "utility.hpp"
namespace tuning {
namespace config {
namespace {
constexpr rf::Frequency low_band_second_lo_frequency(const rf::Frequency target_frequency) {
return 2650000000 - (target_frequency / 7);
}
constexpr rf::Frequency high_band_second_lo_regions_2_and_3(const rf::Frequency target_frequency) {
return (target_frequency < 5100000000)
? (2350000000 + ((target_frequency - 3600000000) / 5))
: (2500000000 + ((target_frequency - 5100000000) / 9))
;
}
constexpr rf::Frequency high_band_second_lo_frequency(const rf::Frequency target_frequency) {
return (target_frequency < 3600000000)
? (2150000000 + (((target_frequency - 2750000000) * 60) / 85))
: high_band_second_lo_regions_2_and_3(target_frequency)
;
}
Config low_band(const rf::Frequency target_frequency) {
const rf::Frequency first_lo_frequency = target_frequency + low_band_second_lo_frequency(target_frequency);
const rf::Frequency second_lo_frequency = first_lo_frequency - target_frequency;
return {
.first_lo_frequency = first_lo_frequency,
.second_lo_frequency = second_lo_frequency,
.rf_path_band = rf::path::Band::Low,
.baseband_q_invert = true,
};
}
Config mid_band(const rf::Frequency target_frequency) {
return {
.first_lo_frequency = 0,
.second_lo_frequency = target_frequency,
.rf_path_band = rf::path::Band::Mid,
.baseband_q_invert = false,
};
}
Config high_band(const rf::Frequency target_frequency) {
const rf::Frequency first_lo_frequency = target_frequency - high_band_second_lo_frequency(target_frequency);
const rf::Frequency second_lo_frequency = target_frequency - first_lo_frequency;
return {
.first_lo_frequency = first_lo_frequency,
.second_lo_frequency = second_lo_frequency,
.rf_path_band = rf::path::Band::High,
.baseband_q_invert = false,
};
}
} /* namespace */
Config create(const rf::Frequency target_frequency) {
/* TODO: This is some lame code. */
if( target_frequency < rf::path::band_low.min ) {
return { };
} else if( target_frequency < rf::path::band_low.max ) {
return low_band(target_frequency);
} else if( target_frequency < rf::path::band_mid.max ) {
return mid_band(target_frequency);
} else if( target_frequency < rf::path::band_high.max ) {
return high_band(target_frequency);
} else {
return { };
}
}
} /* namespace config */
} /* namespace tuning */