Update version.txt

In scanner app, the bandwidth and sampling rate for AM modulation was incorrect. This resulted in high pitched and distorted sound. I have now copied the settings from the Audio receiver app, and now the sound in Scanner sounds good also in AM mode.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,12 +1,18 @@
 ---
 name: Bug report
-about: Create a report to help us improve
+about: Create a report to help us improve the software
 title: ''
 labels: bug
 assignees: ''
 
 ---
 
+----
+
+(Please try the latest nightly release before submitting this. You can find the latest nightly verison here: https://github.com/eried/portapack-mayhem/releases)
+
+----
+
 **Describe the bug**
 A clear and concise description of what the bug is. 
 
@@ -21,9 +27,9 @@ A clear and concise description of what you expected to happen.
 
 **Affected versions**
 Please write any difference related with the Expected behavior, on the following versions:
-* Latest Stable Release
-* Previous one (if any) that did not presented the issue
-* Old versions available here: https://github.com/eried/Research/tree/master/HackRF/PortaPack/old_legacy_firmware
+* Latest Stable release:
+* Latest Nightly release:
+* Previous working release:
 
 **Additional**
 If the bug is difficult to explain, additionally to the text please include images and videos.

.github/ISSUE_TEMPLATE/problem-upgrading-the-firmware.md

@@ -1,18 +1,39 @@
 ---
-name: Problem upgrading the firmware
-about: Deal with the firmware upgrade problems
-title: Problem upgrading the firmware
-labels: ''
+name: Problem upgrading the firmware or booting
+about: If you are having firmware upgrade or booting problems
+title: ''
+labels: 'firmware'
 assignees: ''
 
 ---
 
-**What is happening?**
-Describe here why you are unable to upgrade the firmware. Before describing your problems, **do the following**: 
+----
+Before creating this issue, **do the following**: 
+* Read the Wiki on booting: https://github.com/eried/portapack-mayhem/wiki/Won't-boot
 * Read: https://github.com/eried/portapack-havoc/wiki/Update-firmware
 * Watch carefully: https://www.youtube.com/watch?v=_zx4ZvurgOs
 * (if you are not in Windows) also check: https://www.youtube.com/watch?v=kjFB58Y1TAo
 
+----
+
+**Describe the issue**
+A clear and concise description of what the issue you are facing is. 
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Tap on '....'
+
+
+**My Hardware**
+Please specify what PortaPack hardware version you are using. 
+You can find the list of versions here: https://github.com/eried/portapack-mayhem/wiki/PortaPack-Versions
+
+**Affected versions**
+Please tell us what version you are running. 
+Also please try the latest nightly release before submitting this. 
+You can find the latest nightly version here https://github.com/eried/portapack-mayhem/releases
+
 **Were you able to update the firmware before?**
 Things might be confusing the first time, please check the video available on the link above.
 
@@ -20,4 +41,4 @@ Things might be confusing the first time, please check the video available on th
 If is possible, swap hardware and try again. Also, try different USB cables, even if the one you are using works fine for other purposes.
 
 **Additional**
-Add photos and videos of your procedure.
+If the issue is difficult to explain, additionally to the text please include images and videos.

.github/workflows/past_version.txt

@@ -1 +1 @@
-v1.5.1
+v1.5.3

.github/workflows/version.txt

@@ -1 +1 @@
-v1.5.3
+v1.5.4

.gitignore

@@ -27,7 +27,6 @@
 # Compiled Dynamic libraries
 *.so
 *.dylib
-*.dll
 
 # Fortran module files
 *.mod

firmware/application/apps/ui_scanner.cpp

@@ -540,7 +540,7 @@ size_t ScannerView::change_mode(uint8_t new_mod) { //Before this, do a scan_thre
 		field_bw.set_selected_index(0);
 		receiver_model.set_am_configuration(field_bw.selected_index());
 		field_bw.on_change = [this](size_t n, OptionsField::value_t) { receiver_model.set_am_configuration(n);	};		
-		receiver_model.set_sampling_rate(2000000);receiver_model.set_baseband_bandwidth(2000000); 
+		receiver_model.set_sampling_rate(3072000);	receiver_model.set_baseband_bandwidth(1750000); 
 		break;
 	case WFM:
 		bw.emplace_back("16k", 0);

firmware/application/apps/ui_settings.cpp

@@ -245,13 +245,9 @@ SetUIView::SetUIView(NavigationView& nav) {
 	checkbox_showclock.set_value(!persistent_memory::hide_clock());
 	checkbox_guireturnflag.set_value(persistent_memory::show_gui_return_icon());
 	
-	uint32_t backlight_timer = persistent_memory::config_backlight_timer();
-	if (backlight_timer) {
-		checkbox_bloff.set_value(true);
-		options_bloff.set_by_value(backlight_timer);
-	} else {
-		options_bloff.set_selected_index(0);
-	}
+	const auto backlight_config = persistent_memory::config_backlight_timer();
+	checkbox_bloff.set_value(backlight_config.timeout_enabled());
+	options_bloff.set_by_value(backlight_config.timeout_enum());
 
 	if (persistent_memory::clock_with_date()) {
 		options_clockformat.set_selected_index(1);
@@ -261,11 +257,11 @@ SetUIView::SetUIView(NavigationView& nav) {
 
 
 	button_save.on_select = [&nav, this](Button&) {
-		if (checkbox_bloff.value())
-			persistent_memory::set_config_backlight_timer(options_bloff.selected_index() + 1);
-		else
-			persistent_memory::set_config_backlight_timer(0);
-		
+		persistent_memory::set_config_backlight_timer({
+			(persistent_memory::backlight_timeout_t)options_bloff.selected_index_value(),
+			checkbox_bloff.value()
+		});
+				
 		if (checkbox_showclock.value()){
 		    if (options_clockformat.selected_index() == 1)
 			    persistent_memory::set_clock_with_date(true);    

firmware/application/apps/ui_settings.hpp

@@ -27,6 +27,7 @@
 #include "ui_menu.hpp"
 #include "ui_navigation.hpp"
 #include "ff.h"
+#include "portapack_persistent_memory.hpp"
 
 #include <cstdint>
 
@@ -210,6 +211,8 @@ private:
 	SetFrequencyCorrectionModel form_collect();
 };
 
+using portapack::persistent_memory::backlight_timeout_t;
+
 class SetUIView : public View {
 public:
 	SetUIView(NavigationView& nav);
@@ -241,13 +244,14 @@ private:
 		{ 52, 7 * 16 + 8 },
 		20,
 		{
-			{ "5 seconds", 5 },
-			{ "15 seconds", 15 },
-			{ "30 seconds", 30 },
-			{ "1 minute", 60 },
-			{ "3 minutes", 180 },
-			{ "5 minutes", 300 },
-			{ "10 minutes", 600 }
+			{ "5 seconds",  backlight_timeout_t::Timeout5Sec    },
+			{ "15 seconds", backlight_timeout_t::Timeout15Sec   },
+			{ "30 seconds", backlight_timeout_t::Timeout30Sec   },
+			{ "1 minute",   backlight_timeout_t::Timeout60Sec   },
+			{ "3 minutes",  backlight_timeout_t::Timeout180Sec  },
+			{ "5 minutes",  backlight_timeout_t::Timeout300Sec  },
+			{ "10 minutes", backlight_timeout_t::Timeout600Sec  },
+			{ "1 hour",     backlight_timeout_t::Timeout3600Sec },
 		}
 	};
 	

firmware/application/apps/ui_touch_calibration.cpp

@@ -31,7 +31,7 @@ namespace ui {
 TouchCalibrationView::TouchCalibrationView(
 	NavigationView& nav
 ) : nav { nav },
-	calibration { touch::default_calibration() }
+	calibration { touch::Calibration() }
 {
 	add_children({
 		&image_calibrate_0,

firmware/application/event_m0.cpp

@@ -226,15 +226,17 @@ void EventDispatcher::handle_rtc_tick() {
 
 	portapack::temperature_logger.second_tick();
 	
-	uint32_t backlight_timer = portapack::persistent_memory::config_backlight_timer();
-	if (backlight_timer) {
-		if (portapack::bl_tick_counter == backlight_timer)
+	const auto backlight_timer = portapack::persistent_memory::config_backlight_timer();
+	if (backlight_timer.timeout_enabled()) {
+		if (portapack::bl_tick_counter == backlight_timer.timeout_seconds())
 			set_display_sleep(true);
 		else
 			portapack::bl_tick_counter++;
 	}
 
 	rtc_time::on_tick_second();
+
+	portapack::persistent_memory::cache::persist();
 }
 
 ui::Widget* EventDispatcher::touch_widget(ui::Widget* const w, ui::TouchEvent event) {

firmware/application/portapack.cpp

@@ -215,7 +215,7 @@ static int load_config(){
 	static Optional<int> config_value;
 	if(!config_value.is_valid()){
 		int8_t value = portapack::persistent_memory::config_cpld();
-		if((value <= 0 || value >= 4) && sd_card::status() == sd_card::Status::Mounted){
+		if((value <= 0 || value >= 5) && sd_card::status() == sd_card::Status::Mounted){
 			int data = read_file("/hardware/settings.txt");
 			if(data != -1) {
 				config_value = data;
@@ -235,14 +235,19 @@ static PortaPackModel portapack_model() {
 		const auto switches_state = get_switches_state();
 		if (switches_state[(size_t)ui::KeyEvent::Up]){
 			save_config(1);
-			model = PortaPackModel::R2_20170522;
+			// model = PortaPackModel::R2_20170522; // Commented these out as they should be set down below anyway
 		}
 		else if (switches_state[(size_t)ui::KeyEvent::Down]){
 			save_config(2);
-			model = PortaPackModel::R1_20150901;
+			// model = PortaPackModel::R1_20150901;
 		}
 		else if (switches_state[(size_t)ui::KeyEvent::Left]){
 			save_config(3);
+			// model = PortaPackModel::R1_20150901;
+		}
+		else if (switches_state[(size_t)ui::KeyEvent::Right]){
+			save_config(4);
+			// model = PortaPackModel::R2_20170522;
 		}
 		else if (switches_state[(size_t)ui::KeyEvent::Select]){
 			save_config(0);
@@ -253,6 +258,10 @@ static PortaPackModel portapack_model() {
 			model = PortaPackModel::R2_20170522;
 		} else if (load_config() == 2) {
 			model = PortaPackModel::R1_20150901;
+		} else if (load_config() == 3) {
+			model = PortaPackModel::R1_20150901;
+		} else if (load_config() == 4) {
+			model = PortaPackModel::R2_20170522;
 		} else {
 			if( audio_codec_wm8731.detected() ) {
 				model = PortaPackModel::R1_20150901; // H1R1
@@ -457,6 +466,9 @@ bool init() {
 	i2c0.start(i2c_config_fast_clock);
 	chThdSleepMilliseconds(10);
 
+	/* Cache some configuration data from persistent memory. */
+	persistent_memory::cache::init();
+
 	touch::adc::init();
 	controls_init();
 	chThdSleepMilliseconds(10);
@@ -475,7 +487,7 @@ bool init() {
 	if( !portapack::cpld::update_if_necessary(portapack_cpld_config()) ) {
 		chThdSleepMilliseconds(10);
 		// If using a "2021/12 QFP100", press and hold the left button while booting. Should only need to do once.
-		if (load_config() != 3){
+		if (load_config() != 3 && load_config() != 4){
 			shutdown_base();
 			return false;
 		}

firmware/application/serializer.hpp

@@ -45,6 +45,14 @@ struct serial_format_t {
 	parity_enum parity;
 	uint8_t stop_bits;
 	order_enum bit_order;
+
+	constexpr serial_format_t() :
+		data_bits(7),
+		parity(parity_enum::EVEN),
+		stop_bits(1),
+		bit_order(order_enum::LSB_FIRST)
+	{
+	}
 };
 
 size_t symbol_count(const serial_format_t& serial_format);

firmware/application/touch.cpp

@@ -76,14 +76,6 @@ ui::Point Calibration::translate(const DigitizerPoint& p) const {
 	return { x_clipped, y_clipped };
 }
 
-const Calibration default_calibration() {
-	/* Values derived from one PortaPack H1 unit. */
-	return {
-		{ { { 256, 731 }, { 880, 432 }, { 568, 146 } } },
-		{ { {  32,  48 }, { 208, 168 }, { 120, 288 } } }
-	};
-};
-
 void Manager::feed(const Frame& frame) {
 	// touch_debounce.feed(touch_raw);
 	const auto touch_raw = frame.touch;

firmware/application/touch.hpp

@@ -137,6 +137,15 @@ struct Calibration {
 	{
 	}
 
+	constexpr Calibration() :
+		Calibration(
+			/* Values derived from one PortaPack H1 unit. */
+			{ { { 256, 731 }, { 880, 432 }, { 568, 146 } } },
+			{ { {  32,  48 }, { 208, 168 }, { 120, 288 } } }
+		)
+	{
+	}
+
 	ui::Point translate(const DigitizerPoint& p) const;
 
 private:
@@ -149,8 +158,6 @@ private:
 	int32_t f;
 };
 
-const Calibration default_calibration();
-
 template<size_t N>
 class Filter {
 public:

firmware/common/portapack_persistent_memory.cpp

@@ -28,7 +28,8 @@
 #include "utility.hpp"
 
 #include "memory_map.hpp"
-using portapack::memory::map::backup_ram;
+
+#include "crc.hpp"
 
 #include <algorithm>
 #include <utility>
@@ -67,8 +68,193 @@ using clkout_freq_range_t = range_t<uint32_t>;
 constexpr clkout_freq_range_t clkout_freq_range { 10, 60000 };
 constexpr uint32_t clkout_freq_reset_value { 10000 };
 
+enum data_structure_version_enum : uint32_t {
+	VERSION_CURRENT = 0x10000002,
+};
+
+static const uint32_t TOUCH_CALIBRATION_MAGIC = 0x074af82f;
+
+struct ui_config_t {
+private:
+	enum bits_t {
+		BacklightTimeoutLSB    =  0,
+		BacklightTimeoutEnable =  3,
+		ClkoutFreqLSB          =  4,
+		ShowGUIReturnIcon      = 20,
+		LoadAppSettings        = 21,
+		SaveAppSettings        = 22,
+		ShowBiggerQRCode       = 23,
+		DisableTouchscreen     = 24,
+		HideClock              = 25,
+		ClockWithDate          = 26,
+		ClkOutEnabled          = 27,
+		ConfigSpeaker          = 28,
+		StealthMode            = 29,
+		ConfigLogin            = 30,
+		ConfigSplash           = 31,
+	};
+
+	enum bits_mask_t : uint32_t {
+		BacklightTimeoutMask = ((1 <<  3) - 1) << bits_t::BacklightTimeoutLSB,
+		ClkoutFreqMask       = ((1 << 16) - 1) << bits_t::ClkoutFreqLSB,
+	};
+
+	uint32_t values;
+
+	constexpr bool bit_read(const bits_t n) const {
+		return ((values >> n) & 1) != 0;
+	}
+
+	constexpr void bit_write(const bits_t n, const bool v) {
+		if(bit_read(n) != v) {
+			values ^= 1 << n;
+		}
+	}
+
+public:
+	backlight_config_t config_backlight_timer() {
+		const auto timeout_enum = (backlight_timeout_t)((values & bits_mask_t::BacklightTimeoutMask) >> bits_t::BacklightTimeoutLSB);
+		const bool timeout_enabled = bit_read(bits_t::BacklightTimeoutEnable);
+		return backlight_config_t(timeout_enum, timeout_enabled);
+	}
+
+	void set_config_backlight_timer(const backlight_config_t& new_value) {
+		values = (values & ~bits_mask_t::BacklightTimeoutMask)
+			| ((new_value.timeout_enum() << bits_t::BacklightTimeoutLSB) & bits_mask_t::BacklightTimeoutMask);
+		bit_write(bits_t::BacklightTimeoutEnable, new_value.timeout_enabled());
+	}
+
+	constexpr uint32_t clkout_freq() {
+		uint32_t freq = (values & bits_mask_t::ClkoutFreqMask) >> bits_t::ClkoutFreqLSB;
+		if(freq < clkout_freq_range.minimum || freq > clkout_freq_range.maximum) {
+			values = (values & ~bits_mask_t::ClkoutFreqMask) | (clkout_freq_reset_value << bits_t::ClkoutFreqLSB);
+			return clkout_freq_reset_value;
+		}
+		else {
+			return freq;
+		}
+	}
+
+	constexpr void set_clkout_freq(uint32_t freq) {
+		values = (values & ~bits_mask_t::ClkoutFreqMask) | (clkout_freq_range.clip(freq) << bits_t::ClkoutFreqLSB);
+	}
+
+	// ui_config is an uint32_t var storing information bitwise
+	// bits 0-2 store the backlight timer
+	// bits 4-19 (16 bits) store the clkout frequency
+	// bits 21-31 store the different single bit configs depicted below
+	// bit 20 store the display state of the gui return icon, hidden (0) or shown (1)
+
+	constexpr bool show_gui_return_icon() const { // add return icon in touchscreen menue
+		return bit_read(bits_t::ShowGUIReturnIcon);
+	}
+
+	constexpr void set_gui_return_icon(bool v) {
+		bit_write(bits_t::ShowGUIReturnIcon, v);
+	}
+
+	constexpr bool load_app_settings() const { // load (last saved) app settings on startup of app
+		return bit_read(bits_t::LoadAppSettings);
+	}
+
+	constexpr void set_load_app_settings(bool v) {
+		bit_write(bits_t::LoadAppSettings, v);
+	}
+
+	constexpr bool save_app_settings() const { // save app settings when closing app
+		return bit_read(bits_t::SaveAppSettings);
+	}
+
+	constexpr void set_save_app_settings(bool v) {
+		bit_write(bits_t::SaveAppSettings, v);
+	}
+
+	constexpr bool show_bigger_qr_code() const { // show bigger QR code
+		return bit_read(bits_t::ShowBiggerQRCode);
+	}
+
+	constexpr void set_show_bigger_qr_code(bool v) {
+		bit_write(bits_t::ShowBiggerQRCode, v);
+	}
+
+	constexpr bool disable_touchscreen() const { // Option to disable touch screen
+		return bit_read(bits_t::DisableTouchscreen);
+	}
+
+	constexpr void set_disable_touchscreen(bool v) {
+		bit_write(bits_t::DisableTouchscreen, v);
+	}
+
+	constexpr bool hide_clock() const { // clock hidden from main menu
+		return bit_read(bits_t::HideClock);
+	}
+
+	constexpr void set_clock_hidden(bool v) {
+		bit_write(bits_t::HideClock, v);
+	}
+
+	constexpr bool clock_with_date() const { // show clock with date, if not hidden
+		return bit_read(bits_t::ClockWithDate);
+	}
+
+	constexpr void set_clock_with_date(bool v) {
+		bit_write(bits_t::ClockWithDate, v);
+	}
+
+	constexpr bool clkout_enabled() const {
+		return bit_read(bits_t::ClkOutEnabled);
+	}
+
+	constexpr void set_clkout_enabled(bool v) {
+		bit_write(bits_t::ClkOutEnabled, v);
+	}
+
+	constexpr bool config_speaker() const {
+		return bit_read(bits_t::ConfigSpeaker);
+	}
+
+	constexpr void set_config_speaker(bool v) {
+		bit_write(bits_t::ConfigSpeaker, v);
+	}
+
+	constexpr bool stealth_mode() const {
+		return bit_read(bits_t::StealthMode);
+	}
+
+	constexpr void set_stealth_mode(bool v) {
+		bit_write(bits_t::StealthMode, v);
+	}
+
+	constexpr bool config_login() const {
+		return bit_read(bits_t::ConfigLogin);
+	}
+
+	constexpr void set_config_login(bool v) {
+		bit_write(bits_t::ConfigLogin, v);
+	}
+
+	constexpr bool config_splash() const {
+		return bit_read(bits_t::ConfigSplash);
+	}
+
+	constexpr void set_config_splash(bool v) {
+		bit_write(bits_t::ConfigSplash, v);
+	}
+
+	constexpr ui_config_t() :
+		values(
+		      (1 << ConfigSplash)
+			| (1 << ConfigSpeaker)
+			| (clkout_freq_reset_value << ClkoutFreqLSB)
+			| (7 << BacklightTimeoutLSB)
+		)
+	{
+	}
+};
+
 /* struct must pack the same way on M4 and M0 cores. */
 struct data_t {
+	data_structure_version_enum structure_version;
 	int64_t tuned_frequency;
 	int32_t correction_ppb;
 	uint32_t touch_calibration_magic;
@@ -89,7 +275,7 @@ struct data_t {
 	uint32_t playdead_sequence;
 	
 	// UI
-	uint32_t ui_config;
+	ui_config_t ui_config;
 	
 	uint32_t pocsag_last_address;
 	uint32_t pocsag_ignore_address;
@@ -98,11 +284,142 @@ struct data_t {
 
 	// Hardware
 	uint32_t hardware_config;
+
+	constexpr data_t() :
+		structure_version(data_structure_version_enum::VERSION_CURRENT),
+		tuned_frequency(tuned_frequency_reset_value),
+		correction_ppb(ppb_reset_value),
+		touch_calibration_magic(TOUCH_CALIBRATION_MAGIC),
+		touch_calibration(touch::Calibration()),
+
+		modem_def_index(0),			// TODO: Unused?
+		serial_format(),
+		modem_bw(15000),			// TODO: Unused?
+		afsk_mark_freq(afsk_mark_reset_value),
+		afsk_space_freq(afsk_space_reset_value),
+		modem_baudrate(modem_baudrate_reset_value),
+		modem_repeat(modem_repeat_reset_value),
+
+		playdead_magic(),			// TODO: Unused?
+		playing_dead(),				// TODO: Unused?
+		playdead_sequence(),		// TODO: Unused?
+
+		ui_config(),
+
+		pocsag_last_address(0),		// TODO: A better default?
+		pocsag_ignore_address(0),	// TODO: A better default?
+
+		tone_mix(tone_mix_reset_value),
+
+		hardware_config(0)
+	{
+	}
 };
 
-static_assert(sizeof(data_t) <= backup_ram.size(), "Persistent memory structure too large for VBAT-maintained region");
+struct backup_ram_t {
+private:
+	uint32_t regfile[63];
+	uint32_t check_value;
 
-static data_t* const data = reinterpret_cast<data_t*>(backup_ram.base());
+	static void copy(const backup_ram_t& src, backup_ram_t& dst) {
+		for(size_t i=0; i<63; i++) {
+			dst.regfile[i] = src.regfile[i];
+		}
+		dst.check_value = src.check_value;
+	}
+
+	static void copy_from_data_t(const data_t& src, backup_ram_t& dst) {
+		const uint32_t* const src_words = (uint32_t*)&src;
+		const size_t word_count = (sizeof(data_t) + 3) / 4;
+		for(size_t i=0; i<63; i++) {
+			if(i<word_count) {
+				dst.regfile[i] = src_words[i];
+			} else {
+				dst.regfile[i] = 0;
+			}
+		}
+	}
+
+	uint32_t compute_check_value() {
+		CRC<32> crc { 0x04c11db7, 0xffffffff, 0xffffffff };
+		for(size_t i=0; i<63; i++) {
+			const auto word = regfile[i];
+			crc.process_byte((word >>  0) & 0xff);
+			crc.process_byte((word >>  8) & 0xff);
+			crc.process_byte((word >> 16) & 0xff);
+			crc.process_byte((word >> 24) & 0xff);
+		}
+		return crc.checksum();
+	}
+
+public:
+	/* default constructor */
+	backup_ram_t() :
+		check_value(0)
+	{
+		const data_t defaults = data_t();
+		copy_from_data_t(defaults, *this);
+	}
+
+	/* copy-assignment operator */
+	backup_ram_t& operator=(const backup_ram_t& src) {
+		copy(src, *this);
+		return *this;
+	}
+
+	/* Calculate a check value from `this`, and check against
+	 * the stored value.
+	 */
+	bool is_valid() {
+		return compute_check_value() == check_value;
+	}
+
+	/* Assuming `this` contains valid data, update the checksum
+	 * and copy to the destination.
+	 */
+	void persist_to(backup_ram_t& dst) {
+		check_value = compute_check_value();
+		copy(*this, dst);
+	}
+};
+
+static_assert(sizeof(backup_ram_t) == memory::map::backup_ram.size());
+static_assert(sizeof(data_t) <= sizeof(backup_ram_t) - sizeof(uint32_t));
+
+static backup_ram_t* const backup_ram = reinterpret_cast<backup_ram_t*>(memory::map::backup_ram.base());
+
+static backup_ram_t cached_backup_ram;
+static data_t* const data = reinterpret_cast<data_t*>(&cached_backup_ram);
+
+namespace cache {
+
+void defaults() {
+	cached_backup_ram = backup_ram_t();
+}
+
+void init() {
+	if(backup_ram->is_valid()) {
+		// Copy valid persistent data into cache.
+		cached_backup_ram = *backup_ram;
+
+		// Check that structure data we copied into cache is the expected
+		// version. If not, initialize cache to defaults.
+		if(data->structure_version != data_structure_version_enum::VERSION_CURRENT) {
+			// TODO: Can provide version-to-version upgrade functions here,
+			// if we want to be fancy.
+			defaults();
+		}
+	} else {
+		// Copy defaults into cache.
+		defaults();
+	}
+}
+
+void persist() {
+	cached_backup_ram.persist_to(*backup_ram);
+}
+
+} /* namespace cache */
 
 rf::Frequency tuned_frequency() {
 	rf::tuning_range.reset_if_outside(data->tuned_frequency, tuned_frequency_reset_value);
@@ -124,16 +441,14 @@ void set_correction_ppb(const ppb_t new_value) {
 	portapack::clock_manager.set_reference_ppb(clipped_value);
 }
 
-static constexpr uint32_t touch_calibration_magic = 0x074af82f;
-
 void set_touch_calibration(const touch::Calibration& new_value) {
 	data->touch_calibration = new_value;
-	data->touch_calibration_magic = touch_calibration_magic;
+	data->touch_calibration_magic = TOUCH_CALIBRATION_MAGIC;
 }
 
 const touch::Calibration& touch_calibration() {
-	if( data->touch_calibration_magic != touch_calibration_magic ) {
-		set_touch_calibration(touch::default_calibration());
+	if( data->touch_calibration_magic != TOUCH_CALIBRATION_MAGIC ) {
+		set_touch_calibration(touch::Calibration());
 	}
 	return data->touch_calibration;
 }
@@ -200,122 +515,116 @@ void set_serial_format(const serial_format_t new_value) {
 	data->serial_format = new_value;
 }
 
-// ui_config is an uint32_t var storing information bitwise
-// bits 0-2 store the backlight timer
-// bits 4-19 (16 bits) store the clkout frequency
-// bits 21-31 store the different single bit configs depicted below
-// bit 20 store the display state of the gui return icon, hidden (0) or shown (1)
-
-bool show_gui_return_icon(){ // add return icon in touchscreen menue
-return data->ui_config & (1 << 20);
+bool show_gui_return_icon() { // add return icon in touchscreen menue
+	return data->ui_config.show_gui_return_icon();
 }
 
 bool load_app_settings() { // load (last saved) app settings on startup of app
-	return data->ui_config & (1 << 21);
+	return data->ui_config.load_app_settings();
 }
 
 bool save_app_settings() { // save app settings when closing app
-	return data->ui_config & (1 << 22);
+	return data->ui_config.save_app_settings();
 }
   
 bool show_bigger_qr_code() { // show bigger QR code
-	return data->ui_config & (1 << 23);
+	return data->ui_config.show_bigger_qr_code();
 }
 
 bool disable_touchscreen() { // Option to disable touch screen
-	return data->ui_config & (1 << 24);
+	return data->ui_config.disable_touchscreen();
 }
 
 bool hide_clock() { // clock hidden from main menu
-	return data->ui_config & (1 << 25);
+	return data->ui_config.hide_clock();
 }
 
 bool clock_with_date() { // show clock with date, if not hidden
-	return data->ui_config & (1 << 26);
+	return data->ui_config.clock_with_date();
 }
 
 bool clkout_enabled() {
-	return data->ui_config & (1 << 27);
+	return data->ui_config.clkout_enabled();
 }
 
 bool config_speaker() {
-	return data->ui_config & (1 << 28);
+	return data->ui_config.config_speaker();
 }
+
 bool stealth_mode() {
-	return data->ui_config & (1 << 29);
+	return data->ui_config.stealth_mode();
 }
 
 bool config_login() {
-	return data->ui_config & (1 << 30);
+	return data->ui_config.config_login();
 }
 
 bool config_splash() {
-	return data->ui_config & (1 << 31);
+	return data->ui_config.config_splash();
 }
 
 uint8_t config_cpld() {
 	return data->hardware_config;
 }
 
-uint32_t config_backlight_timer() {
-	const uint32_t timer_seconds[8] = { 0, 5, 15, 30, 60, 180, 300, 600 };
-	return timer_seconds[data->ui_config & 7]; //first three bits, 8 possible values
+backlight_config_t config_backlight_timer() {
+	return data->ui_config.config_backlight_timer();
 }
 
 void set_gui_return_icon(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 20)) | (v << 20);
+	data->ui_config.set_gui_return_icon(v);
 }
 
 void set_load_app_settings(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 21)) | (v << 21);
+	data->ui_config.set_load_app_settings(v);
 }
 
 void set_save_app_settings(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 22)) | (v << 22);
+	data->ui_config.set_save_app_settings(v);
 }
 
 void set_show_bigger_qr_code(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 23)) | (v << 23);
+	data->ui_config.set_show_bigger_qr_code(v);
 }
 
 void set_disable_touchscreen(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 24)) | (v << 24);
+	data->ui_config.set_disable_touchscreen(v);
 }
 
 void set_clock_hidden(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 25)) | (v << 25);
+	data->ui_config.set_clock_hidden(v);
 }
 
 void set_clock_with_date(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 26)) | (v << 26);
+	data->ui_config.set_clock_with_date(v);
 }
 
 void set_clkout_enabled(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 27)) | (v << 27);
+	data->ui_config.set_clkout_enabled(v);
 }
 
 void set_config_speaker(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 28)) | (v << 28);
+	data->ui_config.set_config_speaker(v);
 }
 
 void set_stealth_mode(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 29)) | (v << 29);
+	data->ui_config.set_stealth_mode(v);
 }
 
 void set_config_login(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 30)) | (v << 30);
+	data->ui_config.set_config_login(v);
 }
 
 void set_config_splash(bool v) {
-	data->ui_config = (data->ui_config & ~(1 << 31)) | (v << 31);
+	data->ui_config.set_config_splash(v);
 }
 
 void set_config_cpld(uint8_t i) {
 	data->hardware_config = i;
 }
 
-void set_config_backlight_timer(uint32_t i) {
-	data->ui_config = (data->ui_config & ~7) | (i & 7);
+void set_config_backlight_timer(const backlight_config_t& new_value) {
+	data->ui_config.set_config_backlight_timer(new_value);
 }
 
 /*void set_config_textentry(uint8_t new_value) {
@@ -347,18 +656,11 @@ void set_pocsag_ignore_address(uint32_t address) {
 }
 
 uint32_t clkout_freq() {
-	uint16_t freq = (data->ui_config & 0x000FFFF0) >> 4;
-	if(freq < clkout_freq_range.minimum || freq > clkout_freq_range.maximum) {
-		data->ui_config = (data->ui_config & ~0x000FFFF0) | clkout_freq_reset_value << 4;
-		return clkout_freq_reset_value;
-	}
-	else {
-		return freq;
-	}
+	return data->ui_config.clkout_freq();
 }
 
 void set_clkout_freq(uint32_t freq) {
-	data->ui_config = (data->ui_config & ~0x000FFFF0) | (clkout_freq_range.clip(freq) << 4);
+	data->ui_config.set_clkout_freq(freq);
 }
 
 

firmware/common/portapack_persistent_memory.hpp

@@ -25,6 +25,8 @@
 
 #include <cstdint>
 
+#include "optional.hpp"
+
 #include "rf_path.hpp"
 #include "touch.hpp"
 #include "modems.hpp"
@@ -36,6 +38,77 @@ using namespace serializer;
 namespace portapack {
 namespace persistent_memory {
 
+enum backlight_timeout_t {
+    Timeout5Sec    = 0,
+    Timeout15Sec   = 1,
+    Timeout30Sec   = 2,
+    Timeout60Sec   = 3,
+    Timeout180Sec  = 4,
+    Timeout300Sec  = 5,
+    Timeout600Sec  = 6,
+    Timeout3600Sec = 7,
+};
+
+struct backlight_config_t {
+public:
+    backlight_config_t() :
+        _timeout_enum(backlight_timeout_t::Timeout600Sec),
+        _timeout_enabled(false)
+    {
+    }
+
+    backlight_config_t(
+        backlight_timeout_t timeout_enum,
+        bool timeout_enabled
+    ) :
+        _timeout_enum(timeout_enum),
+        _timeout_enabled(timeout_enabled)
+    {
+    }
+
+    bool timeout_enabled() const {
+        return _timeout_enabled;
+    }
+
+    backlight_timeout_t timeout_enum() const {
+        return _timeout_enum;
+    }
+
+    uint32_t timeout_seconds() const {
+        switch(timeout_enum()) {
+            case Timeout5Sec:    return    5;
+            case Timeout15Sec:   return   15;
+            case Timeout30Sec:   return   30;
+            case Timeout60Sec:   return   60;
+            case Timeout180Sec:  return  180;
+            case Timeout300Sec:  return  300;
+            default:
+            case Timeout600Sec:  return  600;
+            case Timeout3600Sec: return 3600;
+        }
+    }
+
+private:
+    backlight_timeout_t _timeout_enum;
+    bool _timeout_enabled;
+};
+
+namespace cache {
+
+/* Set values in cache to sensible defaults. */
+void defaults();
+
+/* Load cached settings from values in persistent RAM, replacing with defaults
+ * if persistent RAM contents appear to be invalid. */
+void init();
+
+/* Calculate a check value for cached settings, and copy the check value and
+ * settings into persistent RAM. Intended to be called periodically to update
+ * persistent settings with current settings. */
+void persist();
+
+} /* namespace cache */
+
 using ppb_t = int32_t;
 
 rf::Frequency tuned_frequency();
@@ -86,7 +159,7 @@ bool hide_clock();
 bool clock_with_date();
 bool config_login();
 bool config_speaker();
-uint32_t config_backlight_timer();
+backlight_config_t config_backlight_timer();
 bool disable_touchscreen();
 
 void set_gui_return_icon(bool v);
@@ -98,7 +171,7 @@ void set_clock_hidden(bool v);
 void set_clock_with_date(bool v);
 void set_config_login(bool v);
 void set_config_speaker(bool v); 
-void set_config_backlight_timer(uint32_t i);
+void set_config_backlight_timer(const backlight_config_t& new_value);
 void set_disable_touchscreen(bool v);
 
 //uint8_t ui_config_textentry();

firmware/common/utility.hpp

@@ -95,27 +95,27 @@ struct range_t {
 	const T minimum;
 	const T maximum;
 
-	const T& clip(const T& value) const {
+	constexpr const T& clip(const T& value) const {
 		return std::max(std::min(value, maximum), minimum);
 	}
 
-	void reset_if_outside(T& value, const T& reset_value) const {
+	constexpr void reset_if_outside(T& value, const T& reset_value) const {
 		if( (value < minimum ) ||
 			(value > maximum ) ) {
 			value = reset_value;
 		}
 	}
 
-	bool below_range(const T& value) const {
+	constexpr bool below_range(const T& value) const {
 		return value < minimum;
 	}
 
-	bool contains(const T& value) const {
+	constexpr bool contains(const T& value) const {
 		// TODO: Subtle gotcha here! Range test doesn't include maximum!
 		return (value >= minimum) && (value < maximum);
 	}
 
-	bool out_of_range(const T& value) const {
+	constexpr bool out_of_range(const T& value) const {
 		// TODO: Subtle gotcha here! Range test in contains() doesn't include maximum!
 		return !contains(value);
 	}