Improve error handling.

main/epd.c

@@ -109,17 +109,21 @@ static void send_data(unsigned char data)
 static inline void wait_until_idle(void)
 {
 	int busy;
+	int retry = 0, max_retry = 100;
 
-	ESP_LOGI(TAG, "busy...");
-
+	ESP_LOGI(TAG, "display busy...");
 	do {
+		if (retry >= max_retry) {
+			ESP_LOGE(TAG, "display is not responding");
+			return;
+		}
 		vTaskDelay((TickType_t) 20 / portTICK_PERIOD_MS);
 		send_cmd(0x71);
 		busy = gpio_get_level(EPD_BUSY_PIN);
 	} while (busy == 0);
 
 	vTaskDelay((TickType_t) 200 / portTICK_PERIOD_MS);
-	ESP_LOGI(TAG, "ready");
+	ESP_LOGI(TAG, "display ready");
 }
 
 static inline void reset(void)

main/gui.c

@@ -922,24 +922,29 @@ void gui_plot_stocks(struct scrn *sc, struct stock_item *data)
 	int price_min = data->price_min;
 	int price_max = data->price_max;
 
+	ESP_LOGD(TAG, "price min=%d, price max=%d", price_min, price_max);
+
 	int x_step = col_n % data->prices_len >= data->prices_len / 2
 	                 ?  col_n / data->prices_len + 1
 	                 : col_n / data->prices_len;
 	if (x_step == 0)
 		x_step = 1;
-
-	int y_step = row_n / (price_max - price_min);
+
+	int dy = (price_max - price_min) / 100;
+	int y_step = dy != 0 ? row_n / dy : 0;
 	if (y_step == 0)
 		y_step = 1;
 
+	ESP_LOGD(TAG, "x-step=%d, y-step=%d", x_step, y_step);
+
 	int n = col_n * row_n / 8;
 	unsigned char *buf = malloc(sizeof(char) * n);
 
 	for (int i = 0; i < n; i++)
 		buf[i] = 0x0;
 
 	for (int i = 0, x = 0, y_prev = 0; i < data->prices_len && x < col_n; i++, x += x_step) {
-		int y = row_n - (data->prices[i] - price_min) * y_step;
+		int y = row_n - ((data->prices[i] - price_min) / 100) * y_step;
 		if (y < 0)
 			y = line_width - 1;
 		if (y >= row_n)

main/main.c

@@ -20,7 +20,7 @@ const static char *TAG = "app";
 
 void app_main(void)
 {
-	int prev_day;
+	int prev_day, ntp_rc;
 	time_t t;
 	char ts[20];
 	struct tm now;
@@ -38,17 +38,20 @@ void app_main(void)
 	wifi_connect();
 
 	ntp_init();
-	ntp_sync();
 	dht_init();
 	news_init();
 	stock_init();
 	epd_init();
 
+	ntp_rc = ntp_sync();
 	t = time(NULL);
 	now = *localtime(&t);
 	prev_day = now.tm_mday;
 
 	for (;;) {
+		if (!ntp_rc)
+			ntp_rc = ntp_sync();
+
 		t = time(NULL);
 		now = *localtime(&t);
 		strftime(ts, sizeof(ts), "%Y-%m-%d %H:%M:%S", &now);
@@ -58,7 +61,7 @@ void app_main(void)
 		gui_draw_humid(&sc);
 		gui_draw_date(&sc, &now);
 
-		if (!stock || prev_day != now.tm_mday) {
+		if (!stock || (ntp_rc && prev_day != now.tm_mday)) {
 			stock_update();
 			stock = stock_get_item();
 			if (stock) {
@@ -82,7 +85,7 @@ void app_main(void)
 		epd_wake();
 		vTaskDelay(500 / portTICK_PERIOD_MS);	
 		epd_draw(sc.fb, MAXLEN);
-		vTaskDelay(2000 / portTICK_PERIOD_MS);	
+		vTaskDelay(1000 / portTICK_PERIOD_MS);	
 		epd_sleep();
 
 		ESP_LOGI(TAG, "last updated at %s", ts);

main/ntp.c

@@ -13,18 +13,24 @@ void ntp_init(void)
 	setenv("TZ", "CST-8", 1);
 	tzset();
 
-	ESP_LOGI(TAG, "Initializing SNTP");
+	ESP_LOGI(TAG, "initializing SNTP");
 	esp_sntp_config_t sntp_conf = ESP_NETIF_SNTP_DEFAULT_CONFIG(CONFIG_SNTP_TIME_SERVER);
 	ESP_ERROR_CHECK(esp_netif_sntp_init(&sntp_conf));
 }
 
-void ntp_sync(void)
+int ntp_sync(void)
 {
 	int retry = 0;
 	const int retry_count = 15;
 
-	while (esp_netif_sntp_sync_wait(2000 / portTICK_PERIOD_MS) == ESP_ERR_TIMEOUT && ++retry < retry_count)
-		ESP_LOGI(TAG, "Waiting for system time to be set... (%d/%d)", retry, retry_count);
+	while (esp_netif_sntp_sync_wait(2000 / portTICK_PERIOD_MS) == ESP_ERR_TIMEOUT && ++retry < retry_count) {
+		ESP_LOGI(TAG, "waiting for system time to be set... (%d/%d)", retry, retry_count);
+		if (++retry >= retry_count) {
+			ESP_LOGE(TAG, "Failed to sync system time");
+			return 0;
+		}
+	}
 
-	ESP_LOGI(TAG, "System time set.");
+	ESP_LOGI(TAG, "system time set");
+	return 1;
 }

main/ntp.h

@@ -3,6 +3,6 @@
 
 void ntp_init(void);
 
-void ntp_sync(void);
+int ntp_sync(void);
 
 #endif /* NTP_H */

main/stock.c

@@ -84,6 +84,7 @@ static esp_err_t http_evt_handler(esp_http_client_event_t *evt)
 			read_len = 0;
 			ESP_LOGD(TAG, "HTTP_EVENT_ON_FINISH");
 			ESP_LOGD(TAG, "%s", *(char **) evt->user_data);
+			ESP_LOGD(TAG, "response status=%d", esp_http_client_get_status_code(evt->client));
 			break;
 		case HTTP_EVENT_DISCONNECTED:
 			ESP_LOGI(TAG, "HTTP_EVENT_DISCONNECTED");