0、代碼說明
????????本文使用的是ESP32系列的ESP32S3設(shè)備開發(fā)，ESP-IDF框架版本為ESP-IDF V5.1，在VScode下以ESP-IDF插件的形式對設(shè)備開發(fā)。后期經(jīng)過對程序的測試發(fā)現(xiàn)，在ESP-IDF v4.4框架下編譯開發(fā)，也可以實現(xiàn)循環(huán)掃描功能，實現(xiàn)功能的程序源碼Demo見文末。
1、實現(xiàn)背景
????????在嵌入式物聯(lián)網(wǎng)這一類的項目開發(fā)中，硬件設(shè)備常作為客戶端，通過固定的或非固定的服務器IP地址和端口號向服務器進行通信，上傳本地數(shù)據(jù)到服務器中或接收來自服務器的請求數(shù)據(jù)。本文主要解決當服務器IP地址并未固定或者因某種原因?qū)е路掌鞯腎P地址發(fā)生變動，而硬件設(shè)備產(chǎn)品可能已經(jīng)上市交付等其它因素，并不能及時的通過OTA升級更新客戶端的MCU硬件程序，但硬件產(chǎn)品依然需要連接服務器的端口，進行數(shù)據(jù)交互。
????????為了預防避免這些意外，在硬件設(shè)備程序的編寫中，并不能和往常一樣直接固定了服務器IP地址。本博客文章中提供了一種簡單可行的方法，即：客戶端固定了目標服務器的IP端口，但服務器的IP地址并不固定。當然，也可以先進行對某一固定了IP和端口的服務器進行連接，在多次或者一定時間都不能正常接入服務器后，開啟循環(huán)掃描同一網(wǎng)段的服務器IP，連接該固定端口或備用端口。
2、開發(fā)資料參考
樂鑫官方的ESP-IDF編程API參考指南鏈接：API 指南 - ESP32-S3 - — ESP-IDF 編程指南 latest 文檔 (espressif.com)
通過API編程參考，可以查看ESP32所需要的常用API及其使用的Demo案例。
3、程序效果圖
ESP32接入WiFi網(wǎng)絡(luò)后獲取到的IP地址信息
ESP32掃描到在線的IP地址，但未掃描到對應的端口，如果服務器未開啟，則ESP32會一直循環(huán)掃描服務器的IP及端口。
ESP32掃描到服務器的IP地址和端口
服務器的IP地址
ESP32接入服務器后，服務器端收到來自客戶端發(fā)送的數(shù)據(jù)
文章來源：http://www.zghlxwxcb.cn/news/detail-788322.html
4、程序源碼
?①、main.c
#include <stdio.h>
#include <string.h>
#include "esp_wifi.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "network.h"
//設(shè)備啟動接入WiFi后，循環(huán)掃描服務器ip是否在線，通信端口是否打開
int app_main()
{
printf("Program starting...\n");
int ret = 0;
char server_ip[128] = {0};
uint8_t wifi_ssid[] = "imi-12-1719";
uint8_t wifi_passwd[] = "imi?61415926";
device_connect_wifi_ap(wifi_ssid, wifi_passwd);
vTaskDelay(500);
while(1)
{
ret = device_scan_dest_server(server_ip);
if(ret == 0)
{
printf("Server ip:%s\n", server_ip);
break;
}
vTaskDelay(30000 / portTICK_PERIOD_MS);
}
//連接服務器
extern int tcp_sock;
tcp_client_init(server_ip);
char str[] = "hello server!";
send(tcp_sock, str, strlen(str)+1, 0);
close(tcp_sock);
return 0;
}
②、network.c
#include "network.h"
//ESP-IDF v5.1
static const char *TAG = "wifi_station";
int tcp_sock = -1;
int udp_sock = -1;
esp_ping_handle_t ping;
int ping_flag = -1;
enum {
PING_IP_OK = 0,
PING_IP_ERR
};
struct sockaddr_in dest_addr;
/**
* @brief 連接WiFi事件處理器---處理WiFi和IP事件
* @param arg:用戶定義的參數(shù)
* @param event_base:事件基類型
* @param event_id:事件具體ID
* @param event_data:指向事件數(shù)據(jù)的指針
* @retval void
*/
void connect_wifi_ap_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) {
esp_wifi_connect();
} 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;
char addr_str[IP4ADDR_STRLEN_MAX];
ESP_LOGI(TAG, "got ip:%s", esp_ip4addr_ntoa(&event->ip_info.ip, addr_str, IP4ADDR_STRLEN_MAX));
}
}
/**
* @brief 設(shè)備連接WiFi AP熱點
* @param wifi_ssid:WiFi 熱點ID
* @param wifi_passwd:WiFi密碼
* @retval void
*/
void device_connect_wifi_ap(uint8_t *wifi_ssid, uint8_t *wifi_passwd)
{
esp_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_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_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &connect_wifi_ap_event_handler, NULL));
ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &connect_wifi_ap_event_handler, NULL));
wifi_config_t wifi_config;
memcpy(wifi_config.sta.ssid, wifi_ssid, strlen((char *)wifi_ssid)+1);
memcpy(wifi_config.sta.password, wifi_passwd, strlen((char *)wifi_passwd)+1);
ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config));
ESP_ERROR_CHECK(esp_wifi_start());
}
/**
* @brief udp客戶端初始化
* @param None
* @retval 成功返回0，失敗返回-1
*/
int udp_client_init(void)
{
char host_ip[] = HOST_IP_ADDR;
int addr_family = 0;
int ip_protocol = 0;
#if defined(CONFIG_EXAMPLE_IPV4)
//struct sockaddr_in dest_addr;
dest_addr.sin_addr.s_addr = inet_addr(host_ip);
dest_addr.sin_family = AF_INET;
dest_addr.sin_port = htons(PORT);
addr_family = AF_INET;
ip_protocol = IPPROTO_IP;
#elif defined(CONFIG_EXAMPLE_IPV6)
struct sockaddr_in6 dest_addr = {0};
inet6_aton(HOST_IP_ADDR, &dest_addr.sin6_addr);
dest_addr.sin6_family = AF_INET6;
dest_addr.sin6_port = htons(PORT);
dest_addr.sin6_scope_id = esp_netif_get_netif_impl_index(EXAMPLE_INTERFACE);
addr_family = AF_INET6;
ip_protocol = IPPROTO_IPV6;
#elif defined(CONFIG_EXAMPLE_SOCKET_IP_INPUT_STDIN)
struct sockaddr_storage dest_addr = {0};
ESP_ERROR_CHECK(get_addr_from_stdin(PORT, SOCK_DGRAM, &ip_protocol, &addr_family, &dest_addr));
#endif
extern int udp_sock;
udp_sock = socket(addr_family, SOCK_DGRAM, ip_protocol);
if (udp_sock < 0)
{
ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
return -1;
}
ESP_LOGI(TAG, "Socket created, sending to %s:%d", HOST_IP_ADDR, PORT);
return 0;
}
/**
* @brief tcp客戶端初始化
* @param None
* @retval 成功返回0，失敗返回-1
*/
int tcp_client_init(char ip_addr[])
{
//char host_ip[128] = HOST_IP_ADDR;
char host_ip[128] = {0};
memcpy(host_ip, ip_addr, strlen(ip_addr));
int addr_family = 0;
int ip_protocol = 0;
int err = 0;
#if defined(CONFIG_EXAMPLE_IPV4)
struct sockaddr_in dest_addr;
dest_addr.sin_addr.s_addr = inet_addr(host_ip);
dest_addr.sin_family = AF_INET;
dest_addr.sin_port = htons(PORT);
addr_family = AF_INET;
ip_protocol = IPPROTO_IP;
#elif defined(CONFIG_EXAMPLE_IPV6)
struct sockaddr_in6 dest_addr = { 0 };
inet6_aton(host_ip, &dest_addr.sin6_addr);
dest_addr.sin6_family = AF_INET6;
dest_addr.sin6_port = htons(PORT);
dest_addr.sin6_scope_id = esp_netif_get_netif_impl_index(EXAMPLE_INTERFACE);
addr_family = AF_INET6;
ip_protocol = IPPROTO_IPV6;
#elif defined(CONFIG_EXAMPLE_SOCKET_IP_INPUT_STDIN)
struct sockaddr_storage dest_addr = { 0 };
ESP_ERROR_CHECK(get_addr_from_stdin(PORT, SOCK_STREAM, &ip_protocol, &addr_family, &dest_addr));
#endif
extern int tcp_sock;
tcp_sock = socket(addr_family, SOCK_STREAM, ip_protocol);
if (tcp_sock < 0) {
ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
return -1;
}
ESP_LOGI(TAG, "Socket created, connecting to server");
DPRINTF("Socket created, connecting to %s:%d\n", host_ip, PORT);
err = connect(tcp_sock, (struct sockaddr *)&dest_addr, sizeof(struct sockaddr_in6));
if (err != 0) {
ESP_LOGE(TAG, "Socket unable to connect: errno %d", errno);
return -1;
}
ESP_LOGI(TAG, "Successfully connected");
return 0;
}
/**
* @brief 設(shè)備連接服務器
* @param target_ip:目標IP地址
* @retval 成功返回0，失敗返回-1
*/
int device_connect_to_server(char *target_ip)
{
int sock = 0;
struct sockaddr_in serv_addr;
//#define PORT 5005
DPRINTF("FUNCTION:%s\tLINE:%d\n", __FUNCTION__, __LINE__);
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
DPRINTF("\n Socket creation error \n");
close(sock);
return -1;
}
DPRINTF("FUNCTION:%s\tLINE:%d\n", __FUNCTION__, __LINE__);
memset(&serv_addr, '0', sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(PORT);
if(inet_pton(AF_INET, target_ip, &serv_addr.sin_addr)<=0) {
DPRINTF("\nInvalid address/ Address not supported \n");
close(sock);
return -1;
}
DPRINTF("FUNCTION:%s\tLINE:%d\n", __FUNCTION__, __LINE__);
if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
//send(sock, "hello", strlen("hello"), 0);
DPRINTF("\nConnection Failed %s\t%d\n", target_ip, PORT);
close(sock);
return -1;
}
DPRINTF("Connected to %s:%d\n", target_ip, PORT);
//char str[] = "hello server!";
//send(sock, str, strlen(str)+1, 0);
close(sock);
return 0;
}
/**
* @brief TCP掃描同一網(wǎng)段下的目標服務器設(shè)備
* @param target_ip:目標IP地址
* @retval 成功返回0， 失敗返回-1
*/
int device_scan_dest_server(char ip_addr[])
{
char ip_local_addr[128] = {0};
char ip_search_addr[256] = {0};
esp_netif_t *netif = esp_netif_get_handle_from_ifkey("WIFI_STA_DEF");
esp_netif_ip_info_t ip_info;
esp_netif_get_ip_info(netif, &ip_info);
memcpy(ip_local_addr, ip4addr_ntoa((ip4_addr_t *)&ip_info.ip), strlen(ip4addr_ntoa((ip4_addr_t *)&ip_info.ip)));
//char *ip4addr_ntoa(const ip4_addr_t *addr);
printf("device ip:%s\n", ip_local_addr);
//192.168.1.8
int i, self_ip_com = 0;
int tok_cnt = 1;
int ret = -1;
for(i = 0; i < 128; i++)
{
if(ip_local_addr[i] == '.')//獲取所在網(wǎng)段
{
if(tok_cnt == 3)
{
self_ip_com = ip_local_addr[i+1] - '0';
break;
}
tok_cnt++;
}
//DPRINTF("%c %d\n", ip_local_addr[i], i);
}
DPRINTF("self_ip_com:%d\n", self_ip_com);
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
char ip_addr_temp[128] = {0};
strncpy(ip_addr_temp, ip_local_addr, i+1);
DPRINTF("%s\n", ip_addr_temp);
int com;
for(com = 1; com < 255; com++)
{
if(com == self_ip_com)
continue;
sprintf(ip_search_addr, "%s%d", ip_addr_temp, com);
//DPRINTF("%s\n", ip_search_addr);
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
device_ping_ip_addr(ip_search_addr);//ping傳入的ip地址
vTaskDelay(500 / portTICK_PERIOD_MS);
//ping通ip地址后，繼續(xù)判斷是否能夠連接端口(5005)
if(ping_flag == PING_IP_OK)
{
esp_ping_stop(ping);
esp_ping_delete_session(ping);
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
ret = device_connect_to_server(ip_search_addr);
if (ret == 0)
{
DPRINTF("Found the target server.\n");
memcpy(ip_addr, ip_search_addr, strlen(ip_search_addr));
break;
}
}else{
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
//vTaskDelay(300 / portTICK_PERIOD_MS);
esp_ping_stop(ping);
esp_ping_delete_session(ping);
}
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
//DPRINTF("try again.\n");
memset(ip_search_addr, 0, sizeof(ip_search_addr));
}
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
printf("com = %d\n", com);
if(com < 255)
{
DPRINTF("Device scan server success.\n");
return 0;
}else{
DPRINTF("Device scan server failed.\n");
return -1;
}
}
/**
* @brief ping ip地址成功的回調(diào)函數(shù)
* @param handle:ping ip句柄
* @param args:傳入給回調(diào)函數(shù)的參數(shù)
* @retval None
*/
void ping_ip_success(esp_ping_handle_t handle, void *args)
{
// optionally, get callback arguments
// const char* str = (const char*) args;
// DPRINTF("%s\r\n", str); // "foo"
ping_flag = PING_IP_OK;
uint8_t ttl;
uint16_t seqno;
uint32_t elapsed_time, recv_len;
ip_addr_t target_addr;
esp_ping_get_profile(handle, ESP_PING_PROF_SEQNO, &seqno, sizeof(seqno));
esp_ping_get_profile(handle, ESP_PING_PROF_TTL, &ttl, sizeof(ttl));
esp_ping_get_profile(handle, ESP_PING_PROF_IPADDR, &target_addr, sizeof(target_addr));
esp_ping_get_profile(handle, ESP_PING_PROF_SIZE, &recv_len, sizeof(recv_len));
esp_ping_get_profile(handle, ESP_PING_PROF_TIMEGAP, &elapsed_time, sizeof(elapsed_time));
printf("%ld bytes from %s icmp_seq=%d ttl=%d time=%ld ms\n",
recv_len, inet_ntoa(target_addr.u_addr.ip4), seqno, ttl, elapsed_time);
}
/**
* @brief ping ip地址超時的回調(diào)函數(shù)
* @param handle:ping ip句柄
* @param args:傳入給回調(diào)函數(shù)的參數(shù)
* @retval None
*/
void ping_ip_timeout(esp_ping_handle_t handle, void *args)
{
ping_flag = PING_IP_ERR;
uint16_t seqno;
ip_addr_t target_addr;
esp_ping_get_profile(handle, ESP_PING_PROF_SEQNO, &seqno, sizeof(seqno));
esp_ping_get_profile(handle, ESP_PING_PROF_IPADDR, &target_addr, sizeof(target_addr));
printf("From %s icmp_seq=%d timeout\n", inet_ntoa(target_addr.u_addr.ip4), seqno);
}
/**
* @brief ping ip地址結(jié)束的回調(diào)函數(shù)
* @param handle:ping ip句柄
* @param args:傳入給回調(diào)函數(shù)的參數(shù)
* @retval None
*/
void ping_ip_end(esp_ping_handle_t handle, void *args)
{
uint32_t transmitted;
uint32_t received;
uint32_t total_time_ms;
ping_flag = -1;
esp_ping_get_profile(handle, ESP_PING_PROF_REQUEST, &transmitted, sizeof(transmitted));
esp_ping_get_profile(handle, ESP_PING_PROF_REPLY, &received, sizeof(received));
esp_ping_get_profile(handle, ESP_PING_PROF_DURATION, &total_time_ms, sizeof(total_time_ms));
DPRINTF("%ld packets transmitted, %ld received, time %ldms\n", transmitted, received, total_time_ms);
}
/**
* @brief ping ip地址
* @param ip_str:字符串格式的IP地址 "192.168.1.8"
* @retval None
*/
void device_ping_ip_addr(char *ip_str)
{
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
ip_addr_t target_addr;
esp_ping_config_t ping_config = ESP_PING_DEFAULT_CONFIG();
ping_config.interval_ms = 400;
ping_config.timeout_ms = 400;
memset(&target_addr, 0, sizeof(ip_addr_t));
//字符串IP地址轉(zhuǎn)換為ping_addr
if (ipaddr_aton(ip_str, &target_addr)) {
//DPRINTF("轉(zhuǎn)換成功.\n");
ping_config.target_addr = target_addr;
} else {
DPRINTF("Invalid IP address\n");
return ;
}
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
//ping_config.target_addr = target_addr; // target IP address
ping_config.count = ESP_PING_COUNT_INFINITE; // ping in infinite mode, esp_ping_stop can stop it
//設(shè)置回調(diào)函數(shù)
esp_ping_callbacks_t cbs;
cbs.on_ping_success = ping_ip_success;
cbs.on_ping_timeout = ping_ip_timeout;
cbs.on_ping_end = ping_ip_end;
cbs.cb_args = "ping ip"; // arguments that will feed to all callback functions, can be NULL
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
esp_ping_new_session(&ping_config, &cbs, &ping);
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
esp_ping_start(ping);
DPRINTF("%s\t%d\n", __FUNCTION__,__LINE__);
}
③、network.h
#ifndef __NETWORK_H
#define __NETWORK_H
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include "sdkconfig.h"
#include <sys/param.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "freertos/queue.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "esp_netif.h"
#include "lwip/err.h"
#include "lwip/sockets.h"
#include "lwip/inet.h"
#include "lwip/ip4_addr.h"
#include "lwip/sys.h"
#include <lwip/netdb.h>
#include "esp_ping.h"
#include "ping/ping_sock.h"
#include "driver/gpio.h"
#include <unistd.h>
#include <sys/socket.h>
#include <errno.h>
#include <netdb.h> // struct addrinfo
#include <arpa/inet.h>
//#define __DEBUG__ //宏定義調(diào)試打印開關(guān)
#ifdef __DEBUG__
#define DPRINTF(...) printf(__VA_ARGS__) //宏調(diào)試打印函數(shù)定義
#else
#define DPRINTF(...)
#endif
#define WIFI_SSID "tony"
#define WIFI_PASS "1008611123"
#if defined(CONFIG_EXAMPLE_IPV4)
#define HOST_IP_ADDR CONFIG_EXAMPLE_IPV4_ADDR
#elif defined(CONFIG_EXAMPLE_IPV6)
#define HOST_IP_ADDR CONFIG_EXAMPLE_IPV6_ADDR
#else
#define HOST_IP_ADDR "192.168.1.100"
#endif
#define PORT 6666
void connect_wifi_ap_event_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data);
void device_connect_wifi_ap(uint8_t *wifi_ssid, uint8_t *wifi_passwd);
int udp_client_init(void);
int tcp_client_init(char ip_addr[]);
void udp_client_task(void *pvParameters);
void tcp_client_task(void *pvParameters);
void key_udp_task(void *pvParameters);
void key_tcp_task(void *pvParameters);
int device_connect_to_server(char *target_ip);
int device_scan_dest_server(char ip_addr[]);
void ping_ip_success(esp_ping_handle_t handle, void *args);
void ping_ip_timeout(esp_ping_handle_t handle, void *args);
void ping_ip_end(esp_ping_handle_t handle, void *args);
void device_ping_ip_addr(char *ip_str);
extern esp_ping_handle_t ping;
extern int ping_flag;
extern int tcp_sock;
extern int udp_sock;
extern struct sockaddr_in dest_addr;
#endif④、完整工程源碼
? ??【免費】ESP32接入網(wǎng)絡(luò)后，循環(huán)掃描服務器IP及端口是否在線的完整工程demo（ESP-IDF）資源-CSDN文庫文章來源地址http://www.zghlxwxcb.cn/news/detail-788322.html
到了這里，關(guān)于ESP32接入網(wǎng)絡(luò)后，循環(huán)掃描服務器IP及端口狀態(tài)信息（ESP-IDF）的文章就介紹完了。如果您還想了解更多內(nèi)容，請在右上角搜索TOY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！
