Merge branch 'main' of git.zander.im:Zander671/rpi4b-temp-humidity

Makefile

@@ -9,7 +9,7 @@ SRCS=src/main.c src/util.c src/lcd.c src/ths.c src/button.c src/ui/screen.c\
      src/ui/datesel.c src/ui/statsby.c src/ui/datapoints.c src/ui/timesel.c\
      src/ui/statrange.c src/config.c src/ui/blankscreen.c src/drive.c\
      src/ui/exportscreen.c src/ui/setdatescreen.c src/ui/viewdatescreen.c\
-	 src/ui/powerscreen.c
+	 src/ui/powerscreen.c src/ui/settzscreen.c src/ui/cleardatascreen.c
 PROG=rpi4b-temp-humidity
 
 all: config.conf bin/${PROG}
@@ -24,16 +24,19 @@ bin/main.o bin/util.o bin/lcd.o bin/ths.o bin/button.o: src/util.h
 bin/ui/screen.o bin/ui/statsby.o bin/ui/datesel.o: src/util.h
 bin/ui/datapoints.o bin/ui/timesel.o bin/ui/statrange.o: src/util.h
 bin/ui/viewdatescreen.o bin/ui/setdatescreen.o bin/ui/powerscreen.o: src/util.h
+bin/ui/settzscreen.o bin/ui/cleardatascreen.o: src/util.h
 
 bin/main.o bin/lcd.o bin/screen.o bin/ui/datesel.o: src/lcd.h
 bin/ui/statsby.o bin/ui/timesel.o bin/ui/statrange.o: src/lcd.h
 bin/ui/datapoints.o bin/ui/viewdatescreen.o: src/lcd.h
 bin/ui/setdatescreen.o bin/ui/powerscreen.o: src/lcd.h
+bin/ui/settzscreen.o bin/ui/cleardatascreen.o: src/lcd.h
 
 bin/main.o bin/ui/screen.o bin/ui/statsby.o: src/ui/screen.h
 bin/ui/datesel.o bin/ui/datapoints.o bin/ui/timesel.o: src/ui/screen.h
 bin/ui/statrange.o bin/ui/setdatescreen.o: src/ui/screen.h
 bin/ui/viewdatescreen.o bin/ui/powerscreen.o: src/ui/screen.h
+bin/ui/settzscreen.o bin/ui/cleardatascreen.o: src/ui/screen.h
 
 bin/main.o bin/ui/datesel.o bin/ui/statsby.o: src/ui/datesel.h
 bin/ui/datapoints.o bin/ui/timesel.o bin/ui/statrange.o: src/ui/datesel.h
@@ -53,6 +56,8 @@ bin/main.o bin/ui/exportscreen.o: src/ui/exportscreen.h
 bin/main.o bin/ui/setdatescreen.o: src/ui/setdatescreen.h
 bin/main.o bin/ui/viewdatescreen.o: src/ui/viewdatescreen.h
 bin/main.o bin/ui/powerscreen.o: src/ui/powerscreen.h
+bin/main.o bin/ui/settzscreen.o: src/ui/settzscreen.h
+bin/main.o bin/ui/cleardatascreen.o: src/ui/cleardatascreen.h
 bin/main.o bin/drive.o bin/ui/exportscreen.o: src/drive.h
 
 .if "${DEFAULT_TEMP_UNIT}" != "F" && "${DEFAULT_TEMP_UNIT}" != "C" &&\
@@ -71,6 +76,7 @@ DEFINES:=\
 -DDEFAULT_REFRESH_TIME="${DEFAULT_REFRESH_TIME}"\
 -DDEFAULT_TEMP_UNIT="${DEFAULT_TEMP_UNIT}"\
 -DDEFAULT_EXPORT_FILE_NAME="${DEFAULT_EXPORT_FILE_NAME}"\
+-DDEFAULT_TIMEZONE="${DEFAULT_TIMEZONE}"\
 
 ${OBJS}: ${.TARGET:C/^bin/src/:C/.o$/.c/}
 	@mkdir -p ${.TARGET:H}

config.conf.m4

@@ -47,3 +47,8 @@ down_pin = 23
 # The base name for export, .sqlite3 will be appended for SQLite exports and
 # .csv will be appended for CSV exports
 #export_file_name = DEFAULT_EXPORT_FILE_NAME
+
+# The timezone used. This is overridden by the environment variable TZ. See the
+# tzset(3) manual page for more information about the format of this. Leave
+# blank for system default
+#timezone = DEFAULT_TIMEZONE

config.mk

@@ -34,3 +34,8 @@ DEFAULT_TEMP_UNIT=F
 # The base name for export, .sqlite3 will be appended for SQLite exports and
 # .csv will be appended for CSV exports
 DEFAULT_EXPORT_FILE_NAME=env_data
+
+# The timezone used. This is overridden by the environment variable TZ. See the
+# tzset(3) manual page for more information about the format of this. Leave
+# blank for system default
+DEFAULT_TIMEZONE=

src/config.c

@@ -205,6 +205,10 @@ static void set_options_from_entries(struct figpar_config *entries,
     GLOBAL_OPTS.export_file_name = steal_opt_if_set(entries[17].value.str);
     LOG_VERBOSE("Using export_file_name: \"%s\"\n",
                 GLOBAL_OPTS.export_file_name);
+
+    entries[18].type = FIGPAR_TYPE_NONE;
+    GLOBAL_OPTS.timezone = steal_opt_if_set(entries[18].value.str);
+    LOG_VERBOSE("Using timezone: \"%s\"\n", GLOBAL_OPTS.timezone);
 }
 
 static char *strdup_default_opt(const char *def) {
@@ -317,6 +321,12 @@ void parse_config_file(const char *path) {
             .action = parse_str_callback,
             .value = {.str = strdup_default_opt(STRINGIFY(DEFAULT_EXPORT_FILE_NAME))},
         },
+        {
+            .directive = "timezone",
+            .type = FIGPAR_TYPE_STR,
+            .action = parse_str_callback,
+            .value = {.str = strdup_default_opt(STRINGIFY(DEFAULT_TIMEZONE))},
+        },
         { .directive = NULL },
     };
     size_t entry_count = sizeof(entries) / sizeof(struct figpar_config);

src/main.c

@@ -22,6 +22,8 @@
 #include "ui/viewdatescreen.h"
 #include "ui/setdatescreen.h"
 #include "ui/powerscreen.h"
+#include "ui/settzscreen.h"
+#include "ui/cleardatascreen.h"
 
 #include <unistd.h>
 #include <err.h>
@@ -84,9 +86,22 @@ void lock_stat_globals(void);
  */
 #define unlock_stat_globals() pthread_mutex_unlock(&STAT_MUTEX)
 
+// should we restart instead of exiting
+bool SHOULD_RESTART = false;
+bool NEED_CLEAR_TZ = false;
+
 int main(int argc, char *const *argv) {
     parse_arguments(argc, argv);
     parse_config_file(GLOBAL_OPTS.config_path);
+    if (GLOBAL_OPTS.timezone) {
+        if (!getenv("TZ")) {
+            setenv("TZ", GLOBAL_OPTS.timezone, true);
+            NEED_CLEAR_TZ = true;
+        } else {
+            LOG_VERBOSE("Config timezone option shadowed by local environment variable\n");
+        }
+    }
+    tzset();
 
     gpio_handle_t handle = gpio_open_device(GLOBAL_OPTS.gpio_path);
     if (handle == GPIO_INVALID_HANDLE) {
@@ -121,9 +136,11 @@ int main(int argc, char *const *argv) {
     if (GLOBAL_OPTS.bl_pin >= 0) {
         screen_manager_add(screen_manager, blank_screen_new());
     }
+    screen_manager_add(screen_manager, (Screen *) power_screen_new());
     screen_manager_add(screen_manager, (Screen *) view_date_screen_new());
     screen_manager_add(screen_manager, (Screen *) set_date_screen_new());
-    screen_manager_add(screen_manager, (Screen *) power_screen_new());
+    screen_manager_add(screen_manager, (Screen *) set_tz_screen_new());
+    screen_manager_add(screen_manager, (Screen *) clear_data_screen_new());
     while (RUNNING) {
         lock_stat_globals();
         uint32_t temp = LAST_TEMP;
@@ -133,8 +150,6 @@ int main(int argc, char *const *argv) {
         // 10ms is probably faster than anyone will press a button
         usleep(10 * 1000);
     }
-    // this is mostly about LCD and DB cleanup, not freeing memory, this leaks a
-    // lot when caused from something other than the main screen
     screen_manager_delete(screen_manager);
     lcd_close(lcd);
     if (pthread_join(bg_update, NULL) != 0) {
@@ -147,6 +162,14 @@ int main(int argc, char *const *argv) {
     pthread_mutex_destroy(&STAT_MUTEX);
     gpio_close(handle);
     cleanup_options(&GLOBAL_OPTS);
+    if (SHOULD_RESTART) {
+        LOG_VERBOSE("Re-invoking...\n");
+        if (NEED_CLEAR_TZ) {
+            unsetenv("TZ");
+        }
+        execv(argv[0], argv);
+        err(1, "re-invoke with execv(2) failed");
+    }
     return 0;
 }
 
@@ -263,8 +286,13 @@ void update_stats(THS *ths, sqlite3_stmt *insert_statement) {
     sqlite3_bind_int(insert_statement, 3, humid);
     int status = sqlite3_step(insert_statement);
     if (status != SQLITE_DONE) {
-        errx(1, "failed to insert temp. and humid. data into database: %s",
+        warnx("failed to insert temp. and humid. data into database: %s",
               sqlite3_errstr(status));
+        lock_stat_globals();
+        // this means error
+        LAST_TEMP = UINT32_MAX;
+        LAST_HUMID = UINT32_MAX;
+        unlock_stat_globals();
     }
 }
 

src/ui/cleardatascreen.c

@@ -0,0 +1,72 @@
+/*
+ * cleardatascreen.c - Screen for rebooting or halting
+ * Copyright (C) 2024  Alexander Rosenberg
+ *
+ * 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 3 of the License, or (at your option) any later
+ * version. See the LICENSE file for more information.
+ */
+#include "cleardatascreen.h"
+
+#include <err.h>
+
+static bool clear_data_screen_display(ClearDataScreen *screen,
+                                      SensorState *state) {
+    if (state->back_down || (!screen->choice && state->sel_down) ||
+        (screen->done && (state->sel_down || state->up_down ||
+                          state->down_down))) {
+        screen->done = false;
+        screen->error = false;
+        lcd_display_control(state->lcd, LCD_CURSOR_NO_BLINK, LCD_CURSOR_OFF,
+                            LCD_DISPLAY_ON);
+        return true;
+    }
+    if (state->sel_down) {
+        // TODO clear data
+        char *errmsg;
+        sqlite3_exec(state->db, "DELETE FROM env_data;", NULL, NULL, &errmsg);
+        if (errmsg) {
+            warnx("sqlite3 error when clearing database: \"%s\"\n", errmsg);
+            sqlite3_free(errmsg);
+            screen->error = true;
+        } else {
+            LOG_VERBOSE("Database cleared!\n");
+        }
+        screen->need_redraw = true;
+        screen->done = true;
+        return false;
+    }
+    if (screen->need_redraw || state->force_draw || state->up_down ||
+        state->down_down) {
+        screen->need_redraw = false;
+        screen->choice = abs((screen->choice + state->up_down -
+                              state->down_down) % 2);
+        lcd_clear(state->lcd);
+        lcd_move_to(state->lcd, 0, 0);
+        if (screen->done) {
+            lcd_display_control(state->lcd, LCD_CURSOR_NO_BLINK, LCD_CURSOR_OFF,
+                                LCD_DISPLAY_ON);
+            lcd_write_string(state->lcd, screen->error ? "Error!" : "Done!");
+        } else {
+            lcd_write_string(state->lcd, "Really clear?");
+            lcd_move_to(state->lcd, 1, 0);
+            lcd_write_string(state->lcd, ">No >Yes");
+            lcd_move_to(state->lcd, 1, 4 * screen->choice);
+            lcd_display_control(state->lcd, LCD_CURSOR_BLINK, LCD_CURSOR_ON,
+                                LCD_DISPLAY_ON);
+        }
+    }
+    return false;
+}
+
+ClearDataScreen *clear_data_screen_new() {
+    ClearDataScreen *s = malloc_checked(sizeof(ClearDataScreen));
+    screen_init(&s->parent, "Clear data",
+                (ScreenDispatchFunc) clear_data_screen_display,
+                (ScreenCleanupFunc) free);
+    s->choice = 0;
+    s->need_redraw = false;
+    s->done = false;
+    return s;
+}

src/ui/cleardatascreen.h

@@ -0,0 +1,29 @@
+/*
+ * cleardatascreen.c - Screen for rebooting or halting
+ * Copyright (C) 2024  Alexander Rosenberg
+ *
+ * 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 3 of the License, or (at your option) any later
+ * version. See the LICENSE file for more information.
+ */
+#ifndef INCLUDED_CLEARDATASCREEN_H
+#define INCLUDED_CLEARDATASCREEN_H
+
+#include "screen.h"
+
+typedef struct {
+    Screen parent;
+    int choice;
+    bool done;
+    bool need_redraw;
+    bool error;
+} ClearDataScreen;
+
+/*
+ * Create a new ClearDataScreen that will allow the user to wipe data collected
+ * by the device.
+ */
+ClearDataScreen *clear_data_screen_new(void);
+
+#endif

src/ui/exportscreen.c

@@ -375,7 +375,9 @@ static bool export_screen_dispatch(ExportScreen *screen,
         if (confirm_status == EXPORT_CONFIRM_YES) {
             kill(0, SIGUSR1);
             pthread_cancel(screen->backgroud_oper);
+            pthread_detach(screen->backgroud_oper);
             drive_unmount(cur_drive, true);
+            screen->bg_inited = false;
             screen->stage = EXPORT_SCREEN_CANCELED;
             screen->need_redraw = true;
         } else if (confirm_status == EXPORT_CONFIRM_NO) {
@@ -395,11 +397,18 @@ static bool export_screen_dispatch(ExportScreen *screen,
     return false;
 }
 
+static void export_screen_cleanup(ExportScreen *screen) {
+    if (screen->bg_inited) {
+        pthread_cancel(screen->backgroud_oper);
+        pthread_detach(screen->backgroud_oper);
+    }
+}
+
 ExportScreen *export_screen_new() {
     ExportScreen *s = malloc_checked(sizeof(ExportScreen));
     screen_init(&s->parent, "Export",
                 (ScreenDispatchFunc) export_screen_dispatch,
-                (ScreenCleanupFunc) free);
+                (ScreenCleanupFunc) export_screen_cleanup);
     s->read_drives = true;
     s->stage = EXPORT_SCREEN_FORMAT;
     s->format = EXPORT_FORMAT_SQLITE;

src/ui/powerscreen.c

@@ -18,11 +18,14 @@ static bool power_screen_dispatch(PowerScreen *screen,
     if (state->back_down) {
         lcd_display_control(state->lcd, LCD_CURSOR_NO_BLINK, LCD_CURSOR_OFF,
                             LCD_DISPLAY_ON);
-        screen->choice = POWER_SCREEN_REBOOT;
+        screen->choice = POWER_SCREEN_RESTART_PROGRAM;
         return true;
     }
     if (state->sel_down) {
         switch (screen->choice) {
+        case POWER_SCREEN_RESTART_PROGRAM:
+            request_restart();
+            break;
         case POWER_SCREEN_REBOOT:
             LOG_VERBOSE("Rebooting...");
             reboot(RB_AUTOBOOT);
@@ -51,6 +54,9 @@ static bool power_screen_dispatch(PowerScreen *screen,
         lcd_move_to(state->lcd, 1, 0);
         lcd_write_char(state->lcd, '>');
         switch (screen->choice) {
+        case POWER_SCREEN_RESTART_PROGRAM:
+            lcd_write_string(state->lcd, "REINIT");
+            break;
         case POWER_SCREEN_REBOOT:
             lcd_write_string(state->lcd, "REBOOT");
             break;
@@ -70,6 +76,6 @@ PowerScreen *power_screen_new(void) {
     screen_init(&s->parent, "Power options",
                 (ScreenDispatchFunc) power_screen_dispatch,
                 (ScreenCleanupFunc) free);
-    s->choice = POWER_SCREEN_REBOOT;
+    s->choice = POWER_SCREEN_RESTART_PROGRAM;
     return s;
 }

src/ui/powerscreen.h

@@ -15,7 +15,8 @@
 typedef struct {
     Screen parent;
     enum {
-        POWER_SCREEN_REBOOT = 0,
+        POWER_SCREEN_RESTART_PROGRAM = 0,
+        POWER_SCREEN_REBOOT,
         POWER_SCREEN_POWEROFF,
         POWER_SCREEN_NCHOICE,
     };

src/ui/screen.c

@@ -149,9 +149,14 @@ static bool stats_screen_dispatch(StatsScreen *screen, SensorState *state) {
         lcd_clear(state->lcd);
         lcd_write_string(state->lcd, "temp  humi time");
         char buff[17];
-        int cur_len = snprintf(buff, sizeof(buff), "%-4.1f%c %3" PRIu32 "%% ",
+        int cur_len;
+        if (state->temp == UINT32_MAX || state->humid == UINT32_MAX) {
+            cur_len = snprintf(buff, sizeof(buff), "ERROR! ");
+        } else {
+            cur_len = snprintf(buff, sizeof(buff), "%-4.1f%c %3" PRIu32 "%% ",
                                convert_temperature(state->temp),
                                GLOBAL_OPTS.temp_unit, state->humid);
+        }
         struct tm lt;
         localtime_r(&cur_time, &lt);
         strftime(buff + cur_len, sizeof(buff) - cur_len,

src/ui/settzscreen.c

@@ -0,0 +1,585 @@
+/*
+ * settzscreen.c - Screen for setting the timezone
+ * Copyright (C) 2024  Alexander Rosenberg
+ *
+ * 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 3 of the License, or (at your option) any later
+ * version. See the LICENSE file for more information.
+ */
+#include "settzscreen.h"
+
+#include <spawn.h>
+#include <err.h>
+#include <sys/wait.h>
+
+extern char **environ;
+
+static void set_tz_screen_reset(SetTZScreen *screen, SensorState *state) {
+    screen->has_dst = false;
+    screen->stage = SET_TZ_OFFSET;
+    screen->off_sel_stage = TZ_OFFSET_SEL_HOUR;
+    screen->bound_sel_stage = DST_BOUND_SEL_TYPE;
+    tz_offset_reset(&screen->offset);
+    tz_offset_reset(&screen->dst_offset);
+    screen->did_set = false;
+    if (state) {
+        lcd_display_control(state->lcd, LCD_CURSOR_NO_BLINK, LCD_CURSOR_OFF,
+                            LCD_DISPLAY_ON);
+    }
+}
+
+static void set_tz_offset_normalize(TZOffset *offset, bool allow_negative) {
+    if (offset->second < 0) {
+        offset->second = 59;
+        --offset->minute;
+    } else if (offset->second > 59) {
+        offset->second = 0;
+        ++offset->minute;
+    }
+    if (offset->minute < 0) {
+        offset->minute = 59;
+        --offset->hour;
+    } else if (offset->minute > 59) {
+        offset->minute = 0;
+        ++offset->hour;
+    }
+    if (allow_negative) {
+        if (offset->hour < -24) {
+            offset->hour = 24;
+        } else if (offset->hour > 24) {
+            offset->hour = -24;
+        }
+    } else {
+        if (offset->hour < 0) {
+            offset->hour = 24;
+        } else if (offset->hour > 24) {
+            offset->hour = 0;
+        }
+    }
+}
+
+static SetTZScreenAction set_tz_dispatch_select_offset(TZOffsetSelectStage *stage,
+                                                       SensorState *state,
+                                                       TZOffset *target,
+                                                       const char *label,
+                                                       bool force_redraw,
+                                                       bool allow_negative) {
+    if (state->back_down) {
+        if (*stage == TZ_OFFSET_SEL_HOUR) {
+            *stage = TZ_OFFSET_SEL_SECOND;
+            return SET_TZ_BACK;
+        }
+        --*stage;
+        force_redraw = true;
+    }
+    if (state->up_down || state->down_down) {
+        force_redraw = true;
+        int change = state->up_down - state->down_down;
+        switch (*stage) {
+        case TZ_OFFSET_SEL_HOUR:
+            target->hour += change;
+            break;
+        case TZ_OFFSET_SEL_MINUTE:
+            target->minute += change;
+            break;
+        case TZ_OFFSET_SEL_SECOND:
+            target->second += change;
+            break;
+        }
+        set_tz_offset_normalize(target, allow_negative);
+    }
+    if (state->sel_down) {
+        if (*stage == TZ_OFFSET_SEL_SECOND) {
+            *stage = TZ_OFFSET_SEL_HOUR;
+            return SET_TZ_NEXT;
+        }
+        ++*stage;
+        force_redraw = true;
+    }
+    if (force_redraw) {
+        const char *format;
+        int cursor_pos;
+        switch (*stage) {
+        case TZ_OFFSET_SEL_HOUR:
+            format = ">%0*d:%02d:%02d";
+            cursor_pos = 0;
+            break;
+        case TZ_OFFSET_SEL_MINUTE:
+            format = "%0*d:>%02d:%02d";
+            cursor_pos = target->hour < 0 ? 4 : 3;
+            break;
+        case TZ_OFFSET_SEL_SECOND:
+            format = "%0*d:%02d:>%02d";
+            cursor_pos = target->hour < 0 ? 7 : 6;
+            break;
+        default:
+            format = "";
+            cursor_pos = 0;
+            break;
+        }
+        char time_str[17];
+        snprintf(time_str, 17, format, target->hour < 0 ? 3 : 2, target->hour,
+                 target->minute, target->second);
+        lcd_clear(state->lcd);
+        lcd_move_to(state->lcd, 0, 0);
+        lcd_write_string(state->lcd, label);
+        lcd_move_to(state->lcd, 1, 0);
+        lcd_write_string(state->lcd, time_str);
+        lcd_move_to(state->lcd, 1, cursor_pos);
+        lcd_display_control(state->lcd, LCD_CURSOR_BLINK, LCD_CURSOR_ON,
+                            LCD_DISPLAY_ON);
+    }
+    return SET_TZ_CONTINUE;
+}
+
+static void set_tz_prompt_has_dst(SetTZScreen *screen,
+                                  SensorState *state) {
+    if (state->back_down) {
+        --screen->stage;
+        screen->need_redraw = true;
+        screen->off_sel_stage = TZ_OFFSET_SEL_SECOND;
+        return;
+    }
+    if (state->sel_down) {
+        if (screen->has_dst) {
+            screen->stage = SET_TZ_DST_OFFSET;
+        } else {
+            screen->stage = SET_TZ_FINISH;
+        }
+        screen->need_redraw = true;
+        screen->off_sel_stage = TZ_OFFSET_SEL_HOUR;
+        return;
+    }
+    if (state->up_down || state->down_down) {
+        screen->has_dst = abs((((int) screen->has_dst) + state->up_down -
+                               state->down_down) % 2);
+        screen->need_redraw = true;
+    }
+    if (screen->need_redraw) {
+        screen->need_redraw = false;
+        lcd_clear(state->lcd);
+        lcd_move_to(state->lcd, 0, 0);
+        lcd_write_string(state->lcd, "Has DST?");
+        lcd_move_to(state->lcd, 1, 0);
+        lcd_write_string(state->lcd, ">No >Yes");
+        lcd_move_to(state->lcd, 1, screen->has_dst ? 4 : 0);
+    } 
+}
+
+static const char *DST_BOUND_TYPE_LABELS[] = {
+    "Exact Julian",
+    "Leap Julian",
+    "Month Day Week"
+};
+static SetTZScreenAction set_tz_bound_select_type(SetTZScreen *screen,
+                                                  SensorState *state,
+                                                  DSTBound *target,
+                                                  const char *label) {
+    if (state->back_down) {
+        screen->off_sel_stage = TZ_OFFSET_SEL_SECOND;
+        screen->bound_sel_stage = DST_BOUND_SEL_TIME;
+        return SET_TZ_BACK;
+    }
+    if (state->sel_down) {
+        switch (target->type) {
+        case DST_BOUND_EXACT_JULIAN:
+            screen->bound_sel_stage = DST_BOUND_SEL_JULIAN;
+            target->julian_day = 1;
+            break;
+        case DST_BOUND_LEAP_JULAIN:
+            screen->bound_sel_stage = DST_BOUND_SEL_JULIAN;
+            target->julian_day = 0;
+            break;
+        case DST_BOUND_MND:
+            screen->bound_sel_stage = DST_BOUND_SEL_MONTH;
+            target->month = 1;
+            target->week = 1;
+            target->day = 0;
+            break;
+        }
+        target->time.hour = 2;
+        target->time.minute = 0;
+        target->time.second = 0;
+        screen->julian_didgit = 3;
+        screen->need_redraw = true;
+        return SET_TZ_CONTINUE;
+    }
+    if (state->up_down || state->down_down) {
+        int new_type = (((int) target->type) + state->up_down - state->down_down) % 3;
+        if (new_type < 0) {
+            target->type = 2;
+        } else {
+            target->type = new_type;
+        }
+        screen->need_redraw = true;
+    }
+    if (screen->need_redraw) {
+        screen->need_redraw = false;
+        lcd_clear(state->lcd);
+        lcd_move_to(state->lcd, 0, 0);
+        lcd_write_string(state->lcd, label);
+        lcd_write_string(state->lcd, " Type:");
+        lcd_move_to(state->lcd, 1, 0);
+        lcd_write_char(state->lcd, '>');
+        lcd_write_string(state->lcd, DST_BOUND_TYPE_LABELS[target->type]);
+        lcd_move_to(state->lcd, 1, 0);
+    }
+    return SET_TZ_CONTINUE;
+}
+
+static const char *MONTH_ABBREVS[] = {
+    "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov",
+    "Dec",
+};
+static const char *WEEKDAY_ABBREVS[] = {
+    "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
+};
+static SetTZScreenAction set_tz_bound_select_mnd(SetTZScreen *screen,
+                                                 SensorState *state,
+                                                 DSTBound *target,
+                                                 const char *label) {
+    if (state->back_down) {
+        --screen->bound_sel_stage;
+        screen->need_redraw = true;
+        return SET_TZ_CONTINUE;
+    }
+    if (state->sel_down) {
+        screen->need_redraw = true;
+        if (screen->bound_sel_stage == DST_BOUND_SEL_DAY) {
+            screen->off_sel_stage = TZ_OFFSET_SEL_HOUR;
+            screen->bound_sel_stage = DST_BOUND_SEL_TIME;
+            return SET_TZ_CONTINUE;
+        }
+        ++screen->bound_sel_stage;
+    }
+    if (state->up_down || state->down_down) {
+        int change = state->up_down - state->down_down;
+        switch (screen->bound_sel_stage) {
+        case DST_BOUND_SEL_MONTH:
+            target->month += change;
+            if (target->month < 1) {
+                target->month = 1;
+            } else if (target->month > 12) {
+                target->month = 12;
+            }
+            break;
+        case DST_BOUND_SEL_WEEK:
+            target->week += change;
+            if (target->week < 1) {
+                target->week = 1;
+            } else if (target->week > 5) {
+                target->week = 5;
+            }
+            break;
+        case DST_BOUND_SEL_DAY:
+            target->day += change;
+            if (target->day < 0) {
+                target->day = 0;
+            } else if (target->day > 6) {
+                target->day = 6;
+            }
+            break;
+        default:
+            break; // should not happen
+        }
+        screen->need_redraw = true;
+    }
+    if (screen->need_redraw) {
+        screen->need_redraw = false;
+        const char *format;
+        int cursor_pos;
+        switch(screen->bound_sel_stage) {
+        case DST_BOUND_SEL_MONTH:
+            format = ">%s-%d-%s";
+            cursor_pos = 0;
+            break;
+        case DST_BOUND_SEL_WEEK:
+            format = "%s->%d-%s";
+            cursor_pos = 4;
+            break;
+        case DST_BOUND_SEL_DAY:
+            format = "%s-%d->%s";
+            cursor_pos = 7;
+            break;
+        default:
+            // should not happen
+            format = "";
+            cursor_pos = 0;
+            break;
+        }
+        char sel_str[17];
+        snprintf(sel_str, 17, format, MONTH_ABBREVS[target->month - 1],
+                 target->week, WEEKDAY_ABBREVS[target->day]);
+        lcd_clear(state->lcd);
+        lcd_move_to(state->lcd, 0, 0);
+        lcd_write_string(state->lcd, "Mon-Week-Day");
+        lcd_move_to(state->lcd, 1, 0);
+        lcd_write_string(state->lcd, sel_str);
+        lcd_move_to(state->lcd, 1, cursor_pos);
+    }
+    return SET_TZ_CONTINUE;
+}
+
+static int set_tz_normalize_julian(int julian, bool allow_zero) {
+    if (julian <= 0) {
+        return allow_zero ? 0 : 1;
+    } else if (julian > 365) {
+        return 365;
+    }
+    return julian;
+}
+
+static SetTZScreenAction set_tz_dispatch_select_julian(SetTZScreen *screen,
+                                                       SensorState *state,
+                                                       DSTBound *target,
+                                                       const char *label) {
+    if (state->back_down) {
+        screen->need_redraw = true;
+        if (screen->julian_didgit == 3) {
+            screen->bound_sel_stage = DST_BOUND_SEL_TYPE;
+            return SET_TZ_CONTINUE;
+        }
+        ++screen->julian_didgit;
+    }
+    if (state->sel_down) {
+        screen->need_redraw = true;
+        if (screen->julian_didgit == 1) {
+            screen->off_sel_stage = TZ_OFFSET_SEL_HOUR;
+            screen->bound_sel_stage = DST_BOUND_SEL_TIME;
+            return SET_TZ_CONTINUE;
+        }
+        --screen->julian_didgit;
+    }
+    if (state->up_down || state->down_down) {
+        screen->need_redraw = true;
+        int change = state->up_down - state->down_down;
+        int scale = 0;
+        switch (screen->julian_didgit) {
+        case 1: // ones
+            scale = 1;
+            break;
+        case 2: // tens
+            scale = 10;
+            break;
+        case 3: // hundreds
+            scale = 100;
+            break;
+        }
+        bool allow_zero = screen->off_sel_stage == DST_BOUND_LEAP_JULAIN;
+        int new_day = target->julian_day + scale * change;
+        target->julian_day = set_tz_normalize_julian(new_day, allow_zero);
+    }
+    if (screen->need_redraw) {
+        screen->need_redraw = false;
+        char jul_str[4];
+        snprintf(jul_str, 4, "%03d", target->julian_day);
+        lcd_clear(state->lcd);
+        lcd_move_to(state->lcd, 0, 0);
+        lcd_write_string(state->lcd, "Julian Day");
+        lcd_move_to(state->lcd, 1, 0);
+        lcd_write_string(state->lcd, jul_str);
+        lcd_move_to(state->lcd, 1, 3 - screen->julian_didgit);
+    }
+    return SET_TZ_CONTINUE;
+}
+
+static SetTZScreenAction set_tz_dispatch_select_bound(SetTZScreen *screen,
+                                                      SensorState *state,
+                                                      DSTBound *target,
+                                                      const char *label) {
+    SetTZScreenAction action;
+    switch (screen->bound_sel_stage) {
+    case DST_BOUND_SEL_TYPE:
+        return set_tz_bound_select_type(screen, state, target, label);
+    case DST_BOUND_SEL_MONTH:
+    case DST_BOUND_SEL_WEEK:
+    case DST_BOUND_SEL_DAY:
+        return set_tz_bound_select_mnd(screen, state, target, label);
+    case DST_BOUND_SEL_JULIAN:
+        return set_tz_dispatch_select_julian(screen, state, target, label);
+    case DST_BOUND_SEL_TIME:
+        action = set_tz_dispatch_select_offset(&screen->off_sel_stage, state,
+                                               &target->time, "Effect Time:",
+                                               screen->need_redraw, false);
+        switch (action) {
+        case SET_TZ_NEXT:
+            screen->bound_sel_stage = DST_BOUND_SEL_TYPE;
+        case SET_TZ_CONTINUE:
+            screen->need_redraw = false;
+            return action;
+        case SET_TZ_BACK:
+            if (target->type == DST_BOUND_MND) {
+                screen->bound_sel_stage = DST_BOUND_SEL_DAY;
+            } else {
+                screen->julian_didgit = 1;
+                screen->bound_sel_stage = DST_BOUND_SEL_JULIAN;
+            }
+            screen->need_redraw = true;
+            return SET_TZ_CONTINUE;
+        }
+    default:
+        return SET_TZ_BACK;
+    }
+}
+
+static void set_tz_write_dst_bound(FILE *tz, DSTBound *bound) {
+    fputc(',', tz);
+    switch (bound->type) {
+    case DST_BOUND_EXACT_JULIAN:
+        fprintf(tz, "J%d", bound->julian_day);
+        break;
+    case DST_BOUND_LEAP_JULAIN:
+        fprintf(tz, "%d", bound->julian_day);
+        break;
+    case DST_BOUND_MND:
+        fprintf(tz, "M%d.%d.%d", bound->month, bound->week, bound->day);
+        break;
+    }
+    fprintf(tz, "/%02d:%02d:%02d", bound->time.hour, bound->time.minute,
+            bound->time.second);
+}
+
+static bool set_tz_screen_finish(SetTZScreen *screen,
+                                 SensorState *state) {
+    if (!screen->did_set) {
+        screen->did_set =  true;
+        size_t len;
+        char *buf;
+        FILE *tz = open_memstream(&buf, &len);
+        TZOffset *off = &screen->offset;
+        fprintf(tz, "timezone=CTZ%02d:%02d:%02d", off->hour, off->minute, off->second);
+        if (screen->has_dst) {
+            TZOffset *dst_off = &screen->dst_offset;
+            fprintf(tz, "CDST%02d:%02d:%02d", dst_off->hour, dst_off->minute,
+                    dst_off->second);
+            set_tz_write_dst_bound(tz, &screen->start_bound);
+            set_tz_write_dst_bound(tz, &screen->end_bound);
+        }
+        fclose(tz);
+        char *const args[] = {
+            "sysrc",
+            "-f",
+            GLOBAL_OPTS.config_path,
+            buf,
+            NULL
+        };
+        pid_t pid;
+        int exit_status;
+        if (posix_spawnp(&pid, "sysrc", NULL, NULL, args, environ) != 0) {
+            warnx("failed to start sysrc(8)");
+        } else if (waitpid(pid, &exit_status, 0) < 0) {
+            warn("waitpid(2) for sysrc(8) failed");
+        } else if (exit_status != 0) {
+            warnx("sysrc(8) failed to set timezone");
+        } else {
+            LOG_VERBOSE("Set timezone to: \"%s\"\n", buf);
+        }
+        free(buf);
+        request_restart();
+    }
+    if (state->up_down || state->back_down ||
+        state->sel_down || state->down_down) {
+        set_tz_screen_reset(screen, state);
+        return true;
+    }
+    if (screen->need_redraw) {
+        screen->need_redraw = false;
+        lcd_display_control(state->lcd, LCD_CURSOR_NO_BLINK, LCD_CURSOR_OFF,
+                            LCD_DISPLAY_ON);
+        lcd_clear(state->lcd);
+        lcd_move_to(state->lcd, 0, 0);
+        lcd_write_string(state->lcd, "Done!");
+    }
+    return false;
+}
+
+static bool set_tz_screen_dispatch(SetTZScreen *screen,
+                                   SensorState *state) {
+    if (state->force_draw) {
+        screen->need_redraw = true; 
+    }
+    SetTZScreenAction action;
+    switch (screen->stage) {
+    case SET_TZ_OFFSET:
+        action = set_tz_dispatch_select_offset(&screen->off_sel_stage, state,
+                                               &screen->offset, "Offset",
+                                               screen->need_redraw, true);
+        screen->need_redraw = false;
+        switch (action) {
+        case SET_TZ_BACK:
+            set_tz_screen_reset(screen, state);
+            return true;
+        case SET_TZ_CONTINUE:
+            break; // ignore
+        case SET_TZ_NEXT:
+            screen->need_redraw = true;
+            ++screen->stage;
+            break;
+        }
+        break;
+    case SET_TZ_HAS_DST:
+        set_tz_prompt_has_dst(screen, state);
+        break;
+    case SET_TZ_DST_OFFSET:
+        action = set_tz_dispatch_select_offset(&screen->off_sel_stage, state,
+                                               &screen->dst_offset,
+                                               "DST Offset",
+                                               screen->need_redraw, true);
+        screen->need_redraw = false;
+        switch (action) {
+        case SET_TZ_BACK:
+            --screen->stage;
+            screen->need_redraw = true;
+        case SET_TZ_CONTINUE:
+            break; // ignore
+        case SET_TZ_NEXT:
+            screen->need_redraw = true;
+            ++screen->stage;
+            break;
+        }
+        break;
+    case SET_TZ_DST_START:
+        action = set_tz_dispatch_select_bound(screen, state,
+                                              &screen->start_bound, "Start");
+        switch (action) {
+        case SET_TZ_BACK:
+            --screen->stage;
+            screen->need_redraw = true;
+        case SET_TZ_CONTINUE:
+            break; // ignore
+        case SET_TZ_NEXT:
+            screen->need_redraw = true;
+            ++screen->stage;
+            break;
+        }
+        break;
+    case SET_TZ_DST_END:
+        action = set_tz_dispatch_select_bound(screen, state,
+                                              &screen->end_bound, "End");
+        switch (action) {
+        case SET_TZ_BACK:
+            --screen->stage;
+            screen->need_redraw = true;
+        case SET_TZ_CONTINUE:
+            break; // ignore
+        case SET_TZ_NEXT:
+            screen->need_redraw = true;
+            ++screen->stage;
+            break;
+        }
+        break;
+    case SET_TZ_FINISH:
+        return set_tz_screen_finish(screen, state);
+    }
+    return false;
+}
+
+SetTZScreen *set_tz_screen_new() {
+    SetTZScreen *s = malloc_checked(sizeof(SetTZScreen));
+    screen_init(&s->parent, "Set timezone",
+                (ScreenDispatchFunc) set_tz_screen_dispatch,
+                (ScreenCleanupFunc) free);
+    set_tz_screen_reset(s, NULL);
+    return s;
+}

src/ui/settzscreen.h

@@ -0,0 +1,88 @@
+/*
+ * settzscreen.h - Screen for setting the timezone
+ * Copyright (C) 2024  Alexander Rosenberg
+ *
+ * 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 3 of the License, or (at your option) any later
+ * version. See the LICENSE file for more information.
+ */
+#ifndef INCLUDED_SETTZSCREEN_H
+#define INCLUDED_SETTZSCREEN_H
+
+#include "screen.h"
+
+typedef struct {
+    int hour;
+    int minute;
+    int second;
+} TZOffset;
+
+#define tz_offset_reset(o) ((o)->hour = (o)->minute = (o)->second = 0)
+
+typedef struct {
+    enum {
+        DST_BOUND_EXACT_JULIAN = 0,
+        DST_BOUND_LEAP_JULAIN,
+        DST_BOUND_MND,
+    } type;
+    union {
+        struct {
+            int month;
+            int week;
+            int day;
+        };
+        int julian_day;
+    };
+    TZOffset time;
+} DSTBound;
+
+typedef enum {
+    TZ_OFFSET_SEL_HOUR,
+    TZ_OFFSET_SEL_MINUTE,
+    TZ_OFFSET_SEL_SECOND,
+} TZOffsetSelectStage;
+
+typedef enum {
+    DST_BOUND_SEL_TYPE,
+    DST_BOUND_SEL_MONTH,
+    DST_BOUND_SEL_WEEK,
+    DST_BOUND_SEL_DAY,
+    DST_BOUND_SEL_JULIAN,
+    DST_BOUND_SEL_TIME,
+} DSTBoundSelectStage;
+
+typedef enum {
+    SET_TZ_BACK,
+    SET_TZ_CONTINUE,
+    SET_TZ_NEXT,
+} SetTZScreenAction;
+
+typedef struct {
+    Screen parent;
+    enum {
+        SET_TZ_OFFSET,
+        SET_TZ_HAS_DST,
+        SET_TZ_DST_OFFSET,
+        SET_TZ_DST_START,
+        SET_TZ_DST_END,
+        SET_TZ_FINISH,
+    } stage;
+    bool need_redraw;
+    TZOffsetSelectStage off_sel_stage;
+    DSTBoundSelectStage bound_sel_stage;
+    int julian_didgit;
+    TZOffset offset;
+    bool has_dst;
+    TZOffset dst_offset;
+    DSTBound start_bound;
+    DSTBound end_bound;
+    bool did_set;
+} SetTZScreen;
+
+/*
+ * Create a new SetTZScreen that will allow the user the set the time zone.
+ */
+SetTZScreen *set_tz_screen_new(void);
+
+#endif

src/util.c

@@ -19,6 +19,7 @@
 #include <fcntl.h>
 #include <pthread.h>
 #include <errno.h>
+#include <stdatomic.h>
 
 const char *PERIOD_LABELS[] = {
     "HOUR",
@@ -29,6 +30,10 @@ const char *PERIOD_LABELS[] = {
 };
 const size_t NPERIOD = sizeof(PERIOD_LABELS) / sizeof(char *);
 
+// these are defined in main.c
+extern _Atomic bool RUNNING;
+extern bool SHOULD_RESTART;
+
 Options GLOBAL_OPTS;
 
 void cleanup_options(Options *opts) {
@@ -39,6 +44,7 @@ void cleanup_options(Options *opts) {
     free(opts->fail_key);
     free(opts->database_location);
     free(opts->export_file_name);
+    free(opts->timezone);
 }
 
 void *malloc_checked(size_t n) {
@@ -565,3 +571,8 @@ bool mkdirs(const char *path, mode_t mode) {
     free(copy);
     return true;
 }
+
+void request_restart() {
+    RUNNING = false;
+    SHOULD_RESTART = true;
+}

src/util.h

@@ -54,6 +54,7 @@ typedef struct {
     TemperatureUnit temp_unit;
 
     char *export_file_name; // file to export to
+    char *timezone; // default timezone
 } Options;
 extern Options GLOBAL_OPTS;
 
@@ -248,4 +249,10 @@ bool export_database_as_csv(sqlite3 *db, const char *dest);
  */
 bool mkdirs(const char *path, mode_t mode);
 
+/*
+ * Request that this program re-invoke itself with the same arguments. Used to
+ * re-initialize configuration values.
+ */
+void request_restart(void);
+
 #endif