ESP32通过WiFi获取网络时间(NTP)

代码部分

代码由station_example_main的官方例程修改

/* WiFi station ExampleThis example code is in the Public Domain (or CC0 licensed, at your option.)Unless required by applicable law or agreed to in writing, thissoftware is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES ORCONDITIONS OF ANY KIND, either express or implied.
*/
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"#include "lwip/err.h"
#include "lwip/sys.h"
#include "esp_sntp.h"
//#include "lwip/apps/sntp.h"/* The examples use WiFi configuration that you can set via project configuration menuIf you'd rather not, just change the below entries to strings withthe config you want - ie #define EXAMPLE_WIFI_SSID "mywifissid"
*/
#define EXAMPLE_ESP_WIFI_SSID      CONFIG_ESP_WIFI_SSID
#define EXAMPLE_ESP_WIFI_PASS      CONFIG_ESP_WIFI_PASSWORD
#define EXAMPLE_ESP_MAXIMUM_RETRY  CONFIG_ESP_MAXIMUM_RETRY// NTP服务器配置
#define NTP_SERVER1    "pool.ntp.org"
#define NTP_SERVER2    "time.nist.gov"
#define NTP_SERVER3    "cn.pool.ntp.org"// 时区配置(东八区)
#define TIME_ZONE      (+8)#if CONFIG_ESP_WPA3_SAE_PWE_HUNT_AND_PECK
#define ESP_WIFI_SAE_MODE WPA3_SAE_PWE_HUNT_AND_PECK
#define EXAMPLE_H2E_IDENTIFIER ""
#elif CONFIG_ESP_WPA3_SAE_PWE_HASH_TO_ELEMENT
#define ESP_WIFI_SAE_MODE WPA3_SAE_PWE_HASH_TO_ELEMENT
#define EXAMPLE_H2E_IDENTIFIER CONFIG_ESP_WIFI_PW_ID
#elif CONFIG_ESP_WPA3_SAE_PWE_BOTH
#define ESP_WIFI_SAE_MODE WPA3_SAE_PWE_BOTH
#define EXAMPLE_H2E_IDENTIFIER CONFIG_ESP_WIFI_PW_ID
#endif
#if CONFIG_ESP_WIFI_AUTH_OPEN
#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD WIFI_AUTH_OPEN
#elif CONFIG_ESP_WIFI_AUTH_WEP
#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD WIFI_AUTH_WEP
#elif CONFIG_ESP_WIFI_AUTH_WPA_PSK
#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD WIFI_AUTH_WPA_PSK
#elif CONFIG_ESP_WIFI_AUTH_WPA2_PSK
#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD WIFI_AUTH_WPA2_PSK
#elif CONFIG_ESP_WIFI_AUTH_WPA_WPA2_PSK
#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD WIFI_AUTH_WPA_WPA2_PSK
#elif CONFIG_ESP_WIFI_AUTH_WPA3_PSK
#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD WIFI_AUTH_WPA3_PSK
#elif CONFIG_ESP_WIFI_AUTH_WPA2_WPA3_PSK
#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD WIFI_AUTH_WPA2_WPA3_PSK
#elif CONFIG_ESP_WIFI_AUTH_WAPI_PSK
#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD WIFI_AUTH_WAPI_PSK
#endif/* FreeRTOS event group to signal when we are connected*/
static EventGroupHandle_t s_wifi_event_group;/* The event group allows multiple bits for each event, but we only care about two events:* - we are connected to the AP with an IP* - we failed to connect after the maximum amount of retries */
#define WIFI_CONNECTED_BIT BIT0
#define WIFI_FAIL_BIT      BIT1static const char *TAG = "wifi station";static int s_retry_num = 0;static void event_handler(void* arg, esp_event_base_t event_base,int32_t event_id, void* event_data)
{if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {esp_wifi_connect();} else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {if (s_retry_num < EXAMPLE_ESP_MAXIMUM_RETRY) {esp_wifi_connect();s_retry_num++;ESP_LOGI(TAG, "retry to connect to the AP");} else {xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);}ESP_LOGI(TAG,"connect to the AP fail");} else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data;ESP_LOGI(TAG, "got ip:" IPSTR, IP2STR(&event->ip_info.ip));s_retry_num = 0;xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);}
}void wifi_init_sta(void)
{s_wifi_event_group = xEventGroupCreate();ESP_ERROR_CHECK(esp_netif_init());ESP_ERROR_CHECK(esp_event_loop_create_default());esp_netif_create_default_wifi_sta();wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();ESP_ERROR_CHECK(esp_wifi_init(&cfg));esp_event_handler_instance_t instance_any_id;esp_event_handler_instance_t instance_got_ip;ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT,ESP_EVENT_ANY_ID,&event_handler,NULL,&instance_any_id));ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT,IP_EVENT_STA_GOT_IP,&event_handler,NULL,&instance_got_ip));wifi_config_t wifi_config = {.sta = {.ssid = EXAMPLE_ESP_WIFI_SSID,.password = EXAMPLE_ESP_WIFI_PASS,/* Authmode threshold resets to WPA2 as default if password matches WPA2 standards (password len => 8).* If you want to connect the device to deprecated WEP/WPA networks, Please set the threshold value* to WIFI_AUTH_WEP/WIFI_AUTH_WPA_PSK and set the password with length and format matching to* WIFI_AUTH_WEP/WIFI_AUTH_WPA_PSK standards.*/.threshold.authmode = ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD,.sae_pwe_h2e = ESP_WIFI_SAE_MODE,.sae_h2e_identifier = EXAMPLE_H2E_IDENTIFIER,},};ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA) );ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config) );ESP_ERROR_CHECK(esp_wifi_start() );ESP_LOGI(TAG, "wifi_init_sta finished.");/* Waiting until either the connection is established (WIFI_CONNECTED_BIT) or connection failed for the maximum* number of re-tries (WIFI_FAIL_BIT). The bits are set by event_handler() (see above) */EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group,WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,pdFALSE,pdFALSE,portMAX_DELAY);/* xEventGroupWaitBits() returns the bits before the call returned, hence we can test which event actually* happened. */if (bits & WIFI_CONNECTED_BIT) {ESP_LOGI(TAG, "connected to ap SSID:%s password:%s",EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);} else if (bits & WIFI_FAIL_BIT) {ESP_LOGI(TAG, "Failed to connect to SSID:%s, password:%s",EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);} else {ESP_LOGE(TAG, "UNEXPECTED EVENT");}
}// 初始化SNTP服务
void initialize_sntp(void)
{ESP_LOGI(TAG, "初始化SNTP服务");sntp_setoperatingmode(SNTP_OPMODE_POLL);sntp_setservername(0, NTP_SERVER1);sntp_setservername(1, NTP_SERVER2);sntp_setservername(2, NTP_SERVER3);sntp_init();// 设置时区setenv("TZ", "CST-8", 1); // 中国标准时间(东八区)tzset();
}// 获取并打印当前时间
void print_local_time()
{time_t now;struct tm timeinfo;char strftime_buf[64];time(&now);localtime_r(&now, &timeinfo);strftime(strftime_buf, sizeof(strftime_buf), "%c", &timeinfo);ESP_LOGI(TAG, "当前时间: %s", strftime_buf);// 更详细的格式strftime(strftime_buf, sizeof(strftime_buf), "%Y-%m-%d %H:%M:%S", &timeinfo);ESP_LOGI(TAG, "格式化时间: %s", strftime_buf);
}// 等待时间同步
void wait_for_time_sync_to_RTC(void)
{int retry = 0;const int retry_count = 10;while (sntp_get_sync_status() == SNTP_SYNC_STATUS_RESET && ++retry < retry_count) {ESP_LOGI(TAG, "等待系统时间同步 (%d/%d)...", retry, retry_count);vTaskDelay(1000 / portTICK_PERIOD_MS);}if (retry == retry_count) {ESP_LOGE(TAG, "时间同步失败");return;} ESP_LOGI(TAG, "时间同步成功");// 获取NTP时间并设置到RTCtime_t now;struct tm timeinfo;time(&now);localtime_r(&now, &timeinfo);// 这里可以调用ds3231_set_time()//推荐使用RTC芯片，更新RTC芯片的时间ESP_LOGI(TAG, "NTP时间已同步到RTC");}// 主任务
void ntp_task(void *pvParameters)
{// 初始化SNTP服务initialize_sntp();  // 等待时间同步wait_for_time_sync_to_RTC();// 打印当前时间print_local_time(); // 每隔5秒更新时间while (1) {print_local_time();vTaskDelay(5000 / portTICK_PERIOD_MS);}vTaskDelete(NULL);
}void app_main(void)
{//Initialize NVSesp_err_t ret = nvs_flash_init();if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {ESP_ERROR_CHECK(nvs_flash_erase());ret = nvs_flash_init();}ESP_ERROR_CHECK(ret);ESP_LOGI(TAG, "ESP_WIFI_MODE_STA");wifi_init_sta();// 创建NTP任务xTaskCreate(ntp_task, "ntp_task", 4096, NULL, 5, NULL);
}

结果展示

I (609) wifi:dp: 1, bi: 102400, li: 3, scale listen interval from 307200 us to 307200 us
I (619) wifi:set rx beacon pti, rx_bcn_pti: 0, bcn_timeout: 25000, mt_pti: 0, mt_time: 10000
I (689) wifi:AP's beacon interval = 102400 us, DTIM period = 3
I (1639) esp_netif_handlers: sta ip: 192.168.137.121, mask: 255.255.255.0, gw: 192.168.137.1
I (1639) wifi station: got ip:192.168.137.121
I (1639) wifi station: connected to ap SSID:zhaozhong password:12345678
I (1639) wifi station: 初始化SNTP服务
I (1649) wifi station: 等待系统时间同步 (1/10)...
I (1649) main_task: Returned from app_main()
I (2649) wifi station: 等待系统时间同步 (2/10)...
I (3649) wifi station: 等待系统时间同步 (3/10)...
I (4579) wifi:<ba-add>idx:0 (ifx:0, d6:54:8b:b2:90:f3), tid:0, ssn:7, winSize:64
I (4649) wifi station: 时间同步成功
I (4649) wifi station: NTP时间已同步到RTC
I (4649) wifi station: 当前时间: Wed Mar 26 17:53:37 2025
I (4649) wifi station: 格式化时间: 2025-03-26 17:53:37
I (4649) wifi station: 当前时间: Wed Mar 26 17:53:37 2025
I (4659) wifi station: 格式化时间: 2025-03-26 17:53:37
I (9659) wifi station: 当前时间: Wed Mar 26 17:53:42 2025
I (9659) wifi station: 格式化时间: 2025-03-26 17:53:42
I (14659) wifi station: 当前时间: Wed Mar 26 17:53:47 2025
I (14659) wifi station: 格式化时间: 2025-03-26 17:53:47

可以看出，能够准确获取时间。
如果有RTC芯片，可以定时获取网络时间，然后更新RTC芯片时间。使用时间时候从RTC芯片获取时间信息。