Dual Timer, a variant of the Stock Stopwatch (#236)

* init

* advanced latlon setting

* simple functionality done

* lat lon high precision fwd bwd

* edit toggle

* added readme for branch

* DD DMS conversion & cleanup

* DD to OLC conversion

* olc encoding & decoding

* OLC implementation

* swapped bools for modes, code cleanup

* place name editor

* updated button logic, fixed display

* load and save  places in state array

* todo list

* simplified OLC functions

* geohash conversion functions

* geohash display & digit functions

* todo

* finished geohash implementation

* code display function, defaults, bugfixes

* read/write file/reg logic

* long light in DATA to cancel

* write to registry

* todo

* read & write backup register

* file read/write

* todo

* new more concise button logic, optimizations

* todo

* renamed & cleaned up, fixed button logic

* documentation

* documentation

* LAP mode for all coordinate screens

* faster and more precise geohash algorithm

* updated description

* updated docu

* simple place face

* bugfixes, updated documentation

* init

* meh

* added public functions for OLC and Geohash

* randonauting face

* fix

* display fix

* cleanup

* bugfixes

* bugfix

* added place

* fixed TRNG call

* fixed declaration conflict

* modulo bias filter

* simplified things, chance RNG selection

* fixed button logic, better menus

* cleanup

* documentation

* docu fixes

* original README

* updated place_face

* fallback to register location

* removed pointless freq req

* init

* dual chronograph

* documented and cleaned up

* unused var warning fix

* swap TC2 with TC3 to avoid conflict

* conflict

* show active when returning to face

* docu

* removed unneeded file

* added remain

* show screen on startup

* simplified mode button

3 files changed, 446 insertions, 0 deletions

diff --git a/movement/movement_faces.h b/movement/movement_faces.h
index 7ff1d1ee..358333ae 100644
--- a/movement/movement_faces.h
+++ b/movement/movement_faces.h
@@ -87,6 +87,7 @@
 #include "invaders_face.h"
 #include "world_clock2_face.h"
 #include "time_left_face.h"
+#include "dual_timer_face.h"
 // New includes go above this line.
 
 #endif // MOVEMENT_FACES_H_
diff --git a/movement/watch_faces/complication/dual_timer_face.c b/movement/watch_faces/complication/dual_timer_face.c
new file mode 100644
index 00000000..f98c35b4
--- /dev/null
+++ b/movement/watch_faces/complication/dual_timer_face.c
@@ -0,0 +1,334 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2023 Tobias Raayoni Last / @randogoth
+ * Copyright (c) 2022 Andreas Nebinger
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "dual_timer_face.h"
+#include "watch.h"
+#include "watch_utility.h"
+#include "watch_rtc.h"
+
+/*
+ * IMPORTANT: This watch face uses the same TC2 callback counter as the Stock Stopwatch
+ * watch-face. It works through calling a global handler function. The two watch-faces
+ * therefore can't coexist within the same firmware. If you want to compile this watch-face
+ * then you need to remove the line <../watch_faces/complication/stock_stopwatch_face.c \>
+ * from the Makefile.
+ */
+
+// FROM stock_stopwatch_face.c ////////////////////////////////////////////////
+// Copyright (c) 2022 Andreas Nebinger
+
+#if __EMSCRIPTEN__
+#include <emscripten.h>
+#include <emscripten/html5.h>
+#else
+#include "../../../watch-library/hardware/include/saml22j18a.h"
+#include "../../../watch-library/hardware/include/component/tc.h"
+#include "../../../watch-library/hardware/hri/hri_tc_l22.h"
+#endif
+
+static const watch_date_time distant_future = {.unit = {0, 0, 0, 1, 1, 63}};
+static bool _is_running;
+static uint32_t _ticks;
+
+#if __EMSCRIPTEN__
+
+static long _em_interval_id = 0;
+
+void em_dual_timer_cb_handler(void *userData) {
+    // interrupt handler for emscripten 128 Hz callbacks
+    (void) userData;
+    _ticks++;
+}
+
+static void _dual_timer_cb_initialize() { }
+
+static inline void _dual_timer_cb_stop() {
+    emscripten_clear_interval(_em_interval_id);
+    _em_interval_id = 0;
+    _is_running = false;
+}
+
+static inline void _dual_timer_cb_start() {
+    // initiate 128 hz callback
+    _em_interval_id = emscripten_set_interval(em_dual_timer_cb_handler, (double)(1000/128), (void *)NULL);
+}
+
+#else
+
+static inline void _dual_timer_cb_start() {
+    // start the TC2 timer
+    hri_tc_set_CTRLA_ENABLE_bit(TC2);
+    _is_running = true;
+}
+
+static inline void _dual_timer_cb_stop() {
+    // stop the TC2 timer
+    hri_tc_clear_CTRLA_ENABLE_bit(TC2);
+    _is_running = false;
+}
+
+static void _dual_timer_cb_initialize() {
+    // setup and initialize TC2 for a 64 Hz interrupt
+    hri_mclk_set_APBCMASK_TC2_bit(MCLK);
+    hri_gclk_write_PCHCTRL_reg(GCLK, TC2_GCLK_ID, GCLK_PCHCTRL_GEN_GCLK3 | GCLK_PCHCTRL_CHEN);
+    _dual_timer_cb_stop();
+    hri_tc_write_CTRLA_reg(TC2, TC_CTRLA_SWRST);
+    hri_tc_wait_for_sync(TC2, TC_SYNCBUSY_SWRST);
+    hri_tc_write_CTRLA_reg(TC2, TC_CTRLA_PRESCALER_DIV64 | // 32 Khz divided by 64 divided by 4 results in a 128 Hz interrupt
+                           TC_CTRLA_MODE_COUNT8 | 
+                           TC_CTRLA_RUNSTDBY);
+    hri_tccount8_write_PER_reg(TC2, 3);
+    hri_tc_set_INTEN_OVF_bit(TC2);
+    NVIC_ClearPendingIRQ(TC2_IRQn);
+    NVIC_EnableIRQ (TC2_IRQn);
+}
+
+// you need to take stock_stopwatch.c out of the Makefile or this will create a conflict
+// you have to choose between one of the stopwatches
+ void TC2_Handler(void) {
+    // interrupt handler for TC2 (globally!)
+    _ticks++;
+    TC2->COUNT8.INTFLAG.reg |= TC_INTFLAG_OVF;
+}
+
+#endif
+
+// STATIC FUNCTIONS ///////////////////////////////////////////////////////////
+
+/** @brief converts tick counts to duration struct for time display 
+ */
+static dual_timer_duration_t ticks_to_duration(uint32_t ticks) {
+    dual_timer_duration_t duration;
+    uint8_t hours = 0;
+    uint8_t days = 0;
+
+    // count hours and days
+    while (ticks >= (128 * 60 * 60)) {
+        ticks -= (128 * 60 * 60);
+        hours++;
+        if (hours >= 24) {
+            hours -= 24;
+            days++;
+        }
+    }
+
+    // convert minutes, seconds, centiseconds
+    duration.centiseconds = (ticks & 0x7F) * 100 / 128;
+    duration.seconds = (ticks >> 7) % 60;
+    duration.minutes = (ticks >> 7) / 60;
+    duration.hours = hours;
+    duration.days = days;
+
+    return duration;
+}
+
+/** @brief starts one of the dual timers
+ *  @details Starts a dual timer. If no previous timer is running it starts the global
+ *  tick counter. If a previous timer is already running it registers the current tick. 
+ */
+static void start_timer(dual_timer_state_t *state, bool timer) {
+    // if it is not running yet, run it
+    if ( !_is_running ) {
+        _is_running = true;
+        movement_request_tick_frequency(16);
+        state->start_ticks[timer] = 0;
+        state->stop_ticks[timer] = 0;
+        _ticks = 0;
+        _dual_timer_cb_start();
+        movement_schedule_background_task(distant_future);
+    } else {
+        // if another timer is already running save the current tick
+        state->start_ticks[timer] = _ticks;
+        state->stop_ticks[timer] = _ticks;
+    }
+    state->running[timer] = true;
+}
+
+/** @brief stops one of the dual timers
+ *  @details Stops a dual timer. If no other timer is running it stops the global
+ *  tick counter. If another timer is already running it registers the current stop tick. 
+ */
+static void stop_timer(dual_timer_state_t *state, bool timer) {
+    // stop timer and save duration
+    state->stop_ticks[timer] = _ticks;
+    state->duration[timer] = ticks_to_duration(state->stop_ticks[timer] - state->start_ticks[timer]);
+    state->running[timer] = false;
+    // if the other timer is not running, stop callback
+    if ( state->running[!timer] == false ) {
+        _is_running = false;
+        _dual_timer_cb_stop();
+        movement_request_tick_frequency(1);
+        movement_cancel_background_task();
+    }
+}
+
+/** @brief displays the measured time for each of the dual timers
+ *  @details displays the dual timer. Below 1 hour it displays the timed minutes, seconds,
+ *  and centiseconds. Above that it shows the timed hours, minutes, and seconds. If it 
+ *  has run for more than a day it shows the days, hours, and minutes.
+ *  When the timer is running, the colon blinks every half second.
+ *  It also indicates at the top if another counter is running and for how long.
+ */
+static void dual_timer_display(dual_timer_state_t *state) {
+    char buf[11];
+    char oi[3];
+    // get the current time count of the selected counter
+    dual_timer_duration_t timer = state->running[state->show] ? ticks_to_duration(state->stop_ticks[state->show] - state->start_ticks[state->show]) : state->duration[state->show];
+    // get the current time count of the other counter
+    dual_timer_duration_t other = ticks_to_duration(state->stop_ticks[!state->show] - state->start_ticks[!state->show]);
+    
+    if ( timer.days > 0 )
+        sprintf(buf, "%02u%02u%02u", timer.days, timer.hours, timer.minutes);
+    else if ( timer.hours > 0 )
+        sprintf(buf, "%02u%02u%02u", timer.hours, timer.minutes, timer.seconds);
+    else
+        sprintf(buf, "%02u%02u%02u", timer.minutes, timer.seconds, timer.centiseconds);
+    watch_display_string(buf, 4);
+    
+    // which counter is displayed
+    watch_display_string(state->show ? "B" : "A", 0);
+    
+    // indicate whether other counter is running
+    watch_display_string(state->running[!state->show] && (_ticks % 100) < 50 ? "+" : " ", 1);
+    
+    // indicate for how long the other counter has been running
+    sprintf(oi, "%2u", other.days > 0 ? other.days : (other.hours > 0 ? other.hours : (other.minutes > 0 ? other.minutes : (other.seconds > 0 ? other.seconds : other.centiseconds))));
+    watch_display_string( (state->stop_ticks[!state->show] - state->start_ticks[!state->show]) > 0 ? oi : "  ", 2);
+    
+    // blink colon when running
+    if ( timer.centiseconds > 50 || !state->running[state->show] ) watch_set_colon();
+    else watch_clear_colon();
+}
+
+// PUBLIC WATCH FACE FUNCTIONS ////////////////////////////////////////////////
+
+void dual_timer_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr) {
+    (void) settings;
+    (void) watch_face_index;
+    if (*context_ptr == NULL) {
+        *context_ptr = malloc(sizeof(dual_timer_state_t));
+        memset(*context_ptr, 0, sizeof(dual_timer_state_t));
+        _ticks = 0;
+    }
+    if (!_is_running) {
+        _dual_timer_cb_initialize();
+    }
+}
+
+void dual_timer_face_activate(movement_settings_t *settings, void *context) {
+    (void) settings;
+    (void) context;
+    if (_is_running) {
+        movement_schedule_background_task(distant_future);
+    }
+}
+
+bool dual_timer_face_loop(movement_event_t event, movement_settings_t *settings, void *context) {
+    dual_timer_state_t *state = (dual_timer_state_t *)context;
+
+    // timers stop at 99:23:59:59:99
+    if ( (_ticks - state->start_ticks[0]) >= 1105919999 )
+        stop_timer(state, 0);
+
+    if ( (_ticks - state->start_ticks[1]) >= 1105919999 )
+        stop_timer(state, 1);
+
+    switch (event.event_type) {
+        case EVENT_ACTIVATE:
+            watch_set_colon();
+            if (_is_running) {
+                movement_request_tick_frequency(16);
+                if ( state->running[0] )
+                    state->show = 0;
+                else state->show = 1;
+            } else {
+                if (state->stop_ticks[0] > 0 || state->stop_ticks[1] > 0)
+                    dual_timer_display(state);
+                else watch_display_string("A   000000", 0);
+            }
+            break;
+        case EVENT_TICK:
+            if ( _is_running ) {
+                // update stop ticks
+                if ( state->running[0] )
+                    state->stop_ticks[0] = _ticks;
+                if ( state->running[1] )
+                    state->stop_ticks[1] = _ticks;
+                dual_timer_display(state);
+            }
+            break;
+        case EVENT_LIGHT_BUTTON_DOWN:
+            // start/stop timer B
+            state->running[1] = !state->running[1];
+            if ( state->running[1] ) {
+                start_timer(state, 1);
+            } else {
+                stop_timer(state, 1);
+            }
+            break;
+        case EVENT_ALARM_BUTTON_DOWN:
+            // start/stop timer A
+            state->running[0] = !state->running[0];
+            if ( state->running[0] ) {
+                start_timer(state, 0);
+            } else {
+                stop_timer(state, 0);
+            }
+            break;
+        case EVENT_MODE_BUTTON_DOWN:
+            // switch between the timers
+            state->show = !state->show;
+            dual_timer_display(state);
+            break;
+        case EVENT_MODE_BUTTON_UP:
+            // don't switch to next face...
+            break;
+        case EVENT_MODE_LONG_PRESS:
+            // ...but do it on long press MODE!
+            movement_move_to_next_face();
+            break;
+        case EVENT_TIMEOUT:
+            // go back to 
+            if (!_is_running) movement_move_to_face(0);
+            break;
+        case EVENT_LOW_ENERGY_UPDATE:
+            dual_timer_display(state);
+            break;
+        default:
+            return movement_default_loop_handler(event, settings);
+    }
+
+    return true;
+}
+
+void dual_timer_face_resign(movement_settings_t *settings, void *context) {
+    (void) settings;
+    (void) context;
+    movement_cancel_background_task();
+    // handle any cleanup before your watch face goes off-screen.
+}
+
diff --git a/movement/watch_faces/complication/dual_timer_face.h b/movement/watch_faces/complication/dual_timer_face.h
new file mode 100644
index 00000000..d7c6cfa0
--- /dev/null
+++ b/movement/watch_faces/complication/dual_timer_face.h
@@ -0,0 +1,111 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2023 Tobias Raayoni Last / @randogoth
+ * Copyright (c) 2022 Andreas Nebinger
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef DUAL_TIMER_FACE_H_
+#define DUAL_TIMER_FACE_H_
+
+#include "movement.h"
+
+/*
+ * IMPORTANT: This watch face uses the same TC2 callback counter as the Stock Stopwatch
+ * watch-face. It works through calling a global handler function. The two watch-faces
+ * therefore can't coexist within the same firmware. If you want to compile this watch-face
+ * then you need to remove the line <../watch_faces/complication/stock_stopwatch_face.c \>
+ * from the Makefile.
+ */
+
+/*
+ * DUAL TIMER
+ * ==========
+ * 
+ * Inspired by special ops and tactical trope targeted watches like the Nixon Regulus
+ * that feature two chronographs for timing two simultaneous events, here is a watch
+ * face that expands upon Andreas Nebinger's Stock Stopwatch Face code to implement this 
+ * functionality.
+ * 
+ * ALARM starts/stops timer A, resets on the next start
+ * LIGHT starts/stops timer B, resets on the next start
+ * 
+ * When a timer is running, tapping MODE toggles between displaying timers A or B, as
+ * indicated at the top of the display.
+ * 
+ * The currently selected timer shows minutes, seconds, and 100ths of seconds until the
+ * timed event passes the hour mark. Then it shows hours, minutes, and seconds. Once
+ * it runs for more than a day it shows days, hours, and minutes. The blinking colon
+ * indicates that the timer is running.
+ * 
+ * The longest time span the timers are able to track as 99 days and 23:59:59:99 hours and
+ * they will simply stop.
+ * 
+ * If the other timer that is not currently selected is also running then a plus sign is
+ * blinking next to the A or B indicator. Its progress is indicated by showing the timer's
+ * currently highest time unit ( 100ths of seconds if less than a second, seconds if less
+ * than a minute, minutes if less than an hour, hours if less than a day, days if more than
+ * a day).
+ * 
+ * Please Note: If at least one timer is running then the default function of the MODE
+ * button to move to the next watch face is disabled to be able to use it to toggle between
+ * the timers. In this case LONG PRESSING MODE will move to the next face instead of moving
+ * back to the default watch face.
+ *
+ */
+
+typedef struct {
+    uint8_t centiseconds : 7;  // 0-59
+    uint8_t seconds : 6;  // 0-59
+    uint8_t minutes : 6;  // 0-59
+    uint8_t hours : 5;    // 0-23
+    uint8_t days : 7;    // 0-99
+} dual_timer_duration_t;
+
+typedef struct {
+    uint32_t start_ticks[2];
+    uint32_t stop_ticks[2];
+    dual_timer_duration_t duration[2];
+    bool running[2];
+    bool show;
+} dual_timer_state_t;
+
+void dual_timer_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr);
+void dual_timer_face_activate(movement_settings_t *settings, void *context);
+bool dual_timer_face_loop(movement_event_t event, movement_settings_t *settings, void *context);
+void dual_timer_face_resign(movement_settings_t *settings, void *context);
+
+#if __EMSCRIPTEN__
+void em_dual_timer_cb_handler(void *userData);
+#else
+void TC2_Handler(void);
+#endif
+
+#define dual_timer_face ((const watch_face_t){ \
+    dual_timer_face_setup, \
+    dual_timer_face_activate, \
+    dual_timer_face_loop, \
+    dual_timer_face_resign, \
+    NULL, \
+})
+
+#endif // DUAL_TIMER_FACE_H_
+