feat: use RTC for tracking time (#2)

Within this commit, we enable real time counter in ESP32 to reduce the
drift and enable future deep-sleep implementations. Also, this commit
patches some logs to reduce the amount of logs and increases the stack
for debug purposes.

Author: electricalgorithm

.gitignore

@@ -1,3 +1,4 @@
 build/*
 .vscode/*
-.DS_Store
+.DS_Store
+.cache/*

README.md

@@ -3,6 +3,7 @@
 This is a smart-watch project based on ESP32, LVGL and Zephyr RTOS. I started it as a side project to learn about Zephyr, BLE and LVGL. As you can imagine, it was a big kick to learn about many stuff at oonce. Now, I'm proud to present you. Feel free to contribute and/or contact to me!
 
 ### Features
+- Real-Time Counter to Track the Time
 - LVGL for UI and Graphics Rendering
 - BLE Current Time Service (GATT) for Time Synchronization
 - BLE Device Information Service (DIS) for Device Metadata

boards/esp32.overlay

@@ -1,3 +1,7 @@
 &timer0 {
     status = "okay";
+};
+
+&rtc_timer {
+	status = "okay";
 };

prj.conf

@@ -16,7 +16,7 @@ CONFIG_LVGL=y
 CONFIG_LV_FONT_MONTSERRAT_46=y
 CONFIG_LV_FONT_MONTSERRAT_18=y
 # Important for LVGL to work.
-CONFIG_MAIN_STACK_SIZE=4096
+CONFIG_MAIN_STACK_SIZE=8192
 # CONFIG_LV_MEM_CUSTOM=y
 CONFIG_LV_Z_MEM_POOL_SIZE=16384
 

src/bluetooth/infrastructure.c

@@ -41,7 +41,7 @@ uint8_t enable_bluetooth_and_start_advertisement() {
 		return err;
 	}
 
-	LOG_INF("Bluetooth initialized.");
+	LOG_DBG("Bluetooth initialized.");
 
 	if (IS_ENABLED(CONFIG_SETTINGS)) {
 		settings_load();
@@ -53,7 +53,7 @@ uint8_t enable_bluetooth_and_start_advertisement() {
 		return err;
 	}
 
-	LOG_INF("Advertising successfully started.");
+	LOG_DBG("Advertising successfully started.");
     return 0;
 }
 
@@ -66,14 +66,14 @@ uint8_t disable_bluetooth_and_stop_advertisement() {
 		return err;
 	}
 
-	LOG_INF("Advertising successfully stopped.");
+	LOG_DBG("Advertising successfully stopped.");
 
 	err = bt_disable();
 	if (err) {
 		LOG_ERR("Bluetooth failed to disable (err %d).", err);
 		return err;
 	}
 
-	LOG_INF("Bluetooth disabled.");
+	LOG_DBG("Bluetooth disabled.");
 	return 0;
 }

src/main.c

@@ -1,9 +1,3 @@
-/**
- * @file src/main.c
- *
- * @brief Main file for the application.
- */
-
 #include <stdio.h>
 #include <string.h>
 
@@ -19,6 +13,7 @@
 #include <zephyr/drivers/gpio.h>
 #include <zephyr/drivers/pwm.h>
 #include <zephyr/bluetooth/bluetooth.h>
+#include <zephyr/drivers/counter.h>
 
 #include "display/display.h"
 #include "display/screens/home/home.h"
@@ -28,17 +23,15 @@
 #include "bluetooth/services/current_time_service.h"
 
 // Define the logger.
-LOG_MODULE_REGISTER(ZephyrWatch, LOG_LEVEL_DBG);
+LOG_MODULE_REGISTER(ZephyrWatch, LOG_LEVEL_INF);
 
 // Global values to hold time.
 uint32_t unix_time = 1748554674;
 int8_t utc_zone = +2;
 const char* weekdays[] = { "SUN", "MON", "TUE", "WED", "THU", "FRI", "SAT" };
 
 // Define the timer callbacks' prototypes.
-void update_unix_time_callback(struct k_timer *timer);
 void update_clock_view_callback(struct k_timer *timer);
-void update_date_day_view_callback(struct k_timer *timer);
 // Define the work queues' prototypes.
 void clock_update_worker(struct k_work *work);
 void date_day_update_worker(struct k_work *work);
@@ -51,9 +44,30 @@ static struct k_work clock_update_work;
 static struct k_work date_day_update_work;
 
 // Define timers.
-K_TIMER_DEFINE(unix_time_timer, update_unix_time_callback, NULL);
+// K_TIMER_DEFINE(unix_time_timer, update_unix_time_callback, NULL);
 K_TIMER_DEFINE(clock_view_timer, update_clock_view_callback, NULL);
-K_TIMER_DEFINE(date_day_view_timer, update_date_day_view_callback, NULL);
+
+// Create an alarm for 1 second.
+#define ALARM_INTERVAL_US 1000000
+#define ALARM_CHANNEL_ID 0
+
+
+void rtc_counter_isr(
+    const struct device *dev,
+    uint8_t channel_id, 
+    uint32_t ticks,
+    void *user_data)
+{
+    // Cast alarm config from user data.
+    struct counter_alarm_cfg *alarm_cfg = user_data;
+
+    // Reset alarm
+    alarm_cfg->ticks = counter_us_to_ticks(dev, ALARM_INTERVAL_US);
+    counter_set_channel_alarm(dev, ALARM_CHANNEL_ID, alarm_cfg);
+    
+    // Update the second.
+    unix_time++;
+}
 
 
 int main(void) {
@@ -65,61 +79,54 @@ int main(void) {
         LOG_ERR("Cannot create device twin instance.");
         return 0;
     }
-    LOG_INF("Device twin instance created successfully.");
-
-	// Start the timer to track the real time.
-	k_timer_start(&unix_time_timer, K_MSEC(60), K_SECONDS(1));
-	k_timer_start(&clock_view_timer, K_MSEC(60), K_SECONDS(30));
-    k_timer_start(&date_day_view_timer, K_MSEC(60), K_MINUTES(1));
-    LOG_INF("Timers started successfully.");
+    LOG_DBG("Device twin instance created successfully.");
 
     // Check if the display device is ready.
 	const struct device *display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
 	if (!device_is_ready(display_dev)) {
 		LOG_ERR("Display device is not ready, exiting...");
 		return 0;
 	}
-	LOG_INF("Display device is ready.");
+	LOG_DBG("Display device is ready.");
 
     const struct pwm_dt_spec backlight = PWM_DT_SPEC_GET_BY_IDX(DT_NODELABEL(pwm_lcd0), 0);
     if (!pwm_is_ready_dt(&backlight)) {
         LOG_ERR("PWM device is not ready, exiting...");
         return 0;
     }
-	LOG_INF("PWM device is ready.");
+	LOG_DBG("PWM device is ready.");
 
     // Initialize the PWM device.
     ret = pwm_set_dt(&backlight, 500, 250);
     if (ret < 0) {
         LOG_ERR("Failed to set PWM pulse, exiting...");
         return 0;
     }
-	LOG_INF("PWM pulse for LCD backlight set.");
+	LOG_DBG("PWM pulse for LCD backlight set.");
 
     // Initialize the display device with initial GUI.
     display_init();
-	LOG_INF("UI initialized.");
+	LOG_DBG("UI initialized.");
 
     // Start the UI work queue.
     k_work_queue_start(&ui_work_q, ui_stack_area, K_THREAD_STACK_SIZEOF(ui_stack_area), 
     K_PRIO_PREEMPT(5), NULL);
-	LOG_INF("UI work queue started.");
+	LOG_DBG("UI work queue started.");
 
     // Initialize the work items.
     k_work_init(&clock_update_work, clock_update_worker);
     k_work_init(&date_day_update_work, date_day_update_worker);
 
-    // Start timers after work queue is ready - reduced frequency to prevent queue overflow
-    k_timer_start(&unix_time_timer, K_MSEC(1000), K_SECONDS(1));
-    k_timer_start(&clock_view_timer, K_MSEC(2000), K_SECONDS(30));
-    k_timer_start(&date_day_view_timer, K_MSEC(3000), K_MINUTES(1));
-    LOG_INF("Timers are set.");
+    // Start timers after work queue is ready - reduced frequency to prevent queue overflow.
+    k_timer_start(&clock_view_timer, K_MSEC(2000), K_SECONDS(10));
+    k_work_submit_to_queue(&ui_work_q, &date_day_update_work);
+    LOG_DBG("Timers are set.");
 
     // Initialize LVGL first and let UI stabilize
     lv_task_handler();
     display_blanking_off(display_dev);
 
-    // Give the system more time to stabilize before initializing Bluetooth
+    // Give the system more time to stabilize before initializing Bluetooth.
     k_sleep(K_SECONDS(2));
 
     // Initialize the Bluetooth stack.
@@ -128,7 +135,36 @@ int main(void) {
         LOG_ERR("Bluetooth init failed (ret %d).", ret);
         return ret;
     }
-    LOG_INF("Bluetooth subsytem is initialized.");
+    LOG_INF("Started to advertise with Bluetooth.");
+
+    // Set the real time counter to trigger an callback every second.
+    const struct device *real_time_counter = DEVICE_DT_GET(DT_NODELABEL(rtc_timer));
+    if (!device_is_ready(real_time_counter)) {
+        LOG_ERR("Real time counter device is not ready.");
+        return -ENODEV;
+    }
+    LOG_DBG("Real time counter device is ready.");
+
+    // Configure real time counter to track tine.
+    ret = counter_start(real_time_counter);
+    if (ret) {
+        LOG_ERR("Failed to start real time counter (ret %d).", ret);
+        return ret;
+    }
+    LOG_DBG("Real time counter started successfully.");
+
+    struct counter_alarm_cfg alarm_cfg = {
+        .flags = 0,
+        .ticks = counter_us_to_ticks(real_time_counter, ALARM_INTERVAL_US),
+        .callback = rtc_counter_isr,
+        .user_data = &alarm_cfg,
+    };
+    ret = counter_set_channel_alarm(real_time_counter, ALARM_CHANNEL_ID, &alarm_cfg);
+    if (ret) {
+        LOG_ERR("Failed to set channel alarm (ret %d).", ret);
+        return ret;
+    }
+    LOG_DBG("Channel alarm set successfully.");
 
 	while (1) {
 		lv_task_handler();
@@ -141,35 +177,18 @@ int main(void) {
  * It sends an event to the UI work queue to update the clock view.
  */
 void update_clock_view_callback(struct k_timer *timer) {
+    LOG_DBG("Pushing clock_update_work work to ui_work_q.");
     k_work_submit_to_queue(&ui_work_q, &clock_update_work);
 }
 
-/* UPDATE_DATE_DAY_VIEW_CALLBACK
- * This function is called by the timer to update the date and day views.
- * It sends an event to the UI work queue to update the date and day views.
- */
-void update_date_day_view_callback(struct k_timer *timer) {
-    k_work_submit_to_queue(&ui_work_q, &date_day_update_work);
-}
-
-/* UPDATE_UNIX_TIME_CALLBACK
- * This timer callback function runs every second to update
- * the value inside the unix_time to track the real time.
- * It is neccessary to use timers instead of configuring the
- * RTC because the PoC board does not have RTC support in Zephyr.
- */
-void update_unix_time_callback(struct k_timer *timer) {
-	unix_time += 1;
-}
-
 /* UPDATE_GLOBAL_UNIX_TIME
  * Function to update the global unix time from external sources
  * (like Bluetooth CTS). This function will be called by the external
  * sources.
  */
 void update_global_unix_time(uint32_t unix_timestamp) {
     unix_time = unix_timestamp;
-    LOG_INF("Global UNIX time updated to: %u", unix_time);
+    LOG_INF("unix_time is updated to: %u", unix_time);
 
     // Only submit if not already pending.
     if (!k_work_is_pending(&clock_update_work)) {
@@ -187,6 +206,7 @@ void update_global_unix_time(uint32_t unix_timestamp) {
  * calls the home screen set clock function.
  */
 void clock_update_worker(struct k_work *work) {
+    LOG_DBG("unix_time=%u", unix_time);
     // Get the device twin to find UTC zone.
     device_twin_t* device_twin = get_device_twin_instance();
 
@@ -199,6 +219,12 @@ void clock_update_worker(struct k_work *work) {
     if (ret != 0) {
         LOG_ERR("Failed to update the clock view.");
     }
+
+    // Send a date day update worker if 00:00.
+    if (device_twin->current_time.hour == 0 && device_twin->current_time.minute == 0) {
+        k_work_submit_to_queue(&ui_work_q, &date_day_update_work);
+        LOG_DBG("Date and day update worker submitted to queue.");
+    }
 }
 
 /* DATE_DAY_UPDATE_WORKER