Esp8266建立网络连接相关结构体如下：
结构体头文件espconn.h
/** Protocol family and type of the espconn */
enum espconn_type {
ESPCONN_INVALID = 0,
/* ESPCONN_TCP Group */
ESPCONN_TCP = 0x10,
/* ESPCONN_UDP Group */
ESPCONN_UDP = 0x20,
};
/** Current state of the espconn. Non-TCP espconn are always in state ESPCONN_NONE! */
enum espconn_state {
ESPCONN_NONE,
ESPCONN_WAIT,
ESPCONN_LISTEN,
ESPCONN_CONNECT,
ESPCONN_WRITE,
ESPCONN_READ,
ESPCONN_CLOSE
};
typedef struct _esp_tcp {
int remote_port;
int local_port;
uint8 local_ip[4];
uint8 remote_ip[4];
espconn_connect_callback connect_callback;
espconn_reconnect_callback reconnect_callback;
espconn_connect_callback disconnect_callback;
espconn_connect_callback write_finish_fn;
} esp_tcp;
typedef struct _esp_udp {
int remote_port;
int local_port;
uint8 local_ip[4];
uint8 remote_ip[4];
} esp_udp;
/** A callback prototype to inform about events for a espconn */
typedef void (* espconn_recv_callback)(void *arg, char *pdata, unsigned short len);
typedef void (* espconn_sent_callback)(void *arg);
/** A espconn descriptor */
struct espconn {
/** type of the espconn (TCP, UDP) */
enum espconn_type type;
/** current state of the espconn */
enum espconn_state state;
union {
esp_tcp *tcp;
esp_udp *udp;
} proto;
/** A callback function that is informed about events for this espconn */
espconn_recv_callback recv_callback;
espconn_sent_callback sent_callback;
uint8 link_cnt;
void *reverse;
};
域名解析相关
/******************************************************************************
* TypedefName : dns_found_callback
* Description : Callback which is invoked when a hostname is found.
* Parameters : name -- pointer to the name that was looked up.
* ipaddr -- pointer to an ip_addr_t containing the IP address of
* the hostname, or NULL if the name could not be found (or on any
* other error).
* callback_arg -- a user-specified callback argument passed to
* dns_gethostbyname
*******************************************************************************/
typedef void (*dns_found_callback)(const char *name, ip_addr_t *ipaddr, void *callback_arg);
/******************************************************************************
* FunctionName : espconn_gethostbyname
* Description : Resolve a hostname (string) into an IP address.
* Parameters : pespconn -- espconn to resolve a hostname
* hostname -- the hostname that is to be queried
* addr -- pointer to a ip_addr_t where to store the address if
* it is already cached in the dns_table (only valid if ESPCONN_OK
* is returned!)
* found -- a callback function to be called on success, failure
* or timeout (only if ERR_INPROGRESS is returned!)
* Returns : err_t return code
* - ESPCONN_OK if hostname is a valid IP address string or the host
* name is already in the local names table.
* - ESPCONN_INPROGRESS enqueue a request to be sent to the DNS server
* for resolution if no errors are present.
* - ESPCONN_ARG: dns client not initialized or invalid hostname
*******************************************************************************/
err_t espconn_gethostbyname(struct espconn *pespconn, const char *hostname, ip_addr_t *addr, dns_found_callback found);
建立连接步骤示例（Tcp，直接连接ip）
struct espconn pro_TcpClient_conn;//连接结构体
pro_TcpClient_conn.type = ESPCONN_TCP;//TCP
pro_TcpClient_conn.state = ESPCONN_NONE;//连接初始状态
pro_TcpClient_conn.proto.tcp = (esp_tcp *)os_zalloc(sizeof(esp_tcp));//初始化Tcp连接结构体
os_memcpy(pro_TcpClient_conn.proto.tcp->remote_ip, user_param.remote_server_ip, 4);//用户服务器ip地址
pro_TcpClient_conn.proto.tcp->remote_port = user_param.remote_port; // remote port//用户服务器端口
pro_TcpClient_conn.proto.tcp->local_port = espconn_port(); //配置自动本地端口
espconn_regist_connectcb(&pro_TcpClient_conn, pro_client_connect_cb); // 注册连接回调
espconn_regist_reconcb(&pro_TcpClient_conn, pro_client_recon_cb); // 注册重连回调
espconn_connect(&pro_TcpClient_conn);//开始连接
建立连接步骤示例（Tcp，连接域名）
#define NET_DOMAIN "fofso.com"//连接域名
LOCAL os_timer_t test_timer;//定时器
LOCAL struct espconn user_tcp_conn;//Esp网络相关结构体
LOCAL struct _esp_tcp user_tcp;//Tcp结构体
ip_addr_t tcp_server_ip;//ip地址
/******************************************************************************
* FunctionName : user_tcp_recv_cb
* Description : receive callback.
* Parameters : arg -- Additional argument to pass to the callback function
* Returns : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_recv_cb(void *arg, char *pusrdata, unsigned short length)
{
//received some data from tcp connection
os_printf("tcp recv !!! %s
", pusrdata);
}
/******************************************************************************
* FunctionName : user_tcp_sent_cb
* Description : data sent callback.
* Parameters : arg -- Additional argument to pass to the callback function
* Returns : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_sent_cb(void *arg)
{
//data sent successfully
os_printf("tcp sent succeed !!!
");
}
/******************************************************************************
* FunctionName : user_tcp_discon_cb
* Description : disconnect callback.
* Parameters : arg -- Additional argument to pass to the callback function
* Returns : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_discon_cb(void *arg)
{
//tcp disconnect successfully
os_printf("tcp disconnect succeed !!!
");
}
/******************************************************************************
* FunctionName : user_esp_platform_sent
* Description : Processing the application data and sending it to the host
* Parameters : pespconn -- the espconn used to connetion with the host
* Returns : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_sent_data(struct espconn *pespconn)
{
char *pbuf = (char *)os_zalloc(packet_size);
os_sprintf(pbuf, pheadbuffer, NET_DOMAIN);
espconn_sent(pespconn, pbuf, os_strlen(pbuf));
os_free(pbuf);
}
/******************************************************************************
* FunctionName : user_tcp_connect_cb
* Description : A new incoming tcp connection has been connected.
* Parameters : arg -- Additional argument to pass to the callback function
* Returns : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_connect_cb(void *arg)
{
struct espconn *pespconn = arg;
os_printf("connect succeed !!!
");
espconn_regist_recvcb(pespconn, user_tcp_recv_cb);
espconn_regist_sentcb(pespconn, user_tcp_sent_cb);
espconn_regist_disconcb(pespconn, user_tcp_discon_cb);
user_sent_data(pespconn);
}
/******************************************************************************
* FunctionName : user_tcp_recon_cb
* Description : reconnect callback, error occured in TCP connection.
* Parameters : arg -- Additional argument to pass to the callback function
* Returns : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_recon_cb(void *arg, sint8 err)
{
//error occured , tcp connection broke. user can try to reconnect here.
os_printf("reconnect callback, error code %d !!!
",err);
}
#ifdef DNS_ENABLE
/******************************************************************************
* FunctionName : user_dns_found
* Description : dns found callback
* Parameters : name -- pointer to the name that was looked up.
* ipaddr -- pointer to an ip_addr_t containing the IP address of
* the hostname, or NULL if the name could not be found (or on any
* other error).
* callback_arg -- a user-specified callback argument passed to
* dns_gethostbyname
* Returns : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
{
struct espconn *pespconn = (struct espconn *)arg;
if (ipaddr == NULL)
{
os_printf("user_dns_found NULL
");
return;
}
//dns got ip
os_printf("user_dns_found %d.%d.%d.%d
",
*((uint8 *)&ipaddr->addr), *((uint8 *)&ipaddr->addr + 1),
*((uint8 *)&ipaddr->addr + 2), *((uint8 *)&ipaddr->addr + 3));
if (tcp_server_ip.addr == 0 && ipaddr->addr != 0)
{
// dns succeed, create tcp connection
os_timer_disarm(&test_timer);
tcp_server_ip.addr = ipaddr->addr;
os_memcpy(pespconn->proto.tcp->remote_ip, &ipaddr->addr, 4); // remote ip of tcp server which get by dns
pespconn->proto.tcp->remote_port = user_param.remote_port;
pespconn->proto.tcp->local_port = espconn_port(); //local port of ESP8266
espconn_regist_connectcb(pespconn, user_tcp_connect_cb); // register connect callback
espconn_regist_reconcb(pespconn, user_tcp_recon_cb); // register reconnect callback as error handler
espconn_connect(pespconn); // tcp connect
}
}
/******************************************************************************
* FunctionName : user_esp_platform_dns_check_cb
* Description : 1s time callback to check dns found
* Parameters : arg -- Additional argument to pass to the callback function
* Returns : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_dns_check_cb(void *arg)
{
struct espconn *pespconn = arg;
espconn_gethostbyname(pespconn, NET_DOMAIN, &tcp_server_ip, user_dns_found); // recall DNS function
os_timer_arm(&test_timer, 1000, 0);
}
#endif
/******************************************************************************
* FunctionName : user_check_ip
* Description : check whether get ip addr or not
* Parameters : none
* Returns : none
*******************************************************************************/
void ICACHE_FLASH_ATTR
user_check_ip(void)
{
struct ip_info ipconfig;
//disarm timer first
os_timer_disarm(&test_timer);
//get ip info of ESP8266 station
wifi_get_ip_info(STATION_IF, &ipconfig);
if (wifi_station_get_connect_status() == STATION_GOT_IP && ipconfig.ip.addr != 0)
{
os_printf("got ip !!!
");
// Connect to tcp server as NET_DOMAIN
user_tcp_conn.proto.tcp = &user_tcp;
user_tcp_conn.type = ESPCONN_TCP;
user_tcp_conn.state = ESPCONN_NONE;
#ifdef DNS_ENABLE
tcp_server_ip.addr = 0;
espconn_gethostbyname(&user_tcp_conn, NET_DOMAIN, &tcp_server_ip, user_dns_found); // DNS function
os_timer_setfn(&test_timer, (os_timer_func_t *)user_dns_check_cb, &user_tcp_conn);
os_timer_arm(&test_timer, 1000, 0);
#else
const char esp_tcp_server_ip[4] = {X, X, X, X}; // remote IP of TCP server
os_memcpy(user_tcp_conn.proto.tcp->remote_ip, esp_tcp_server_ip, 4);
user_tcp_conn.proto.tcp->remote_port = user_param.remote_port;
user_tcp_conn.proto.tcp->local_port = espconn_port(); //local port of ESP8266
espconn_regist_connectcb(&user_tcp_conn, user_tcp_connect_cb); // register connect callback
espconn_regist_reconcb(&user_tcp_conn, user_tcp_recon_cb); // register reconnect callback as error handler
espconn_connect(&user_tcp_conn);
#endif
}
else
{
if ((wifi_station_get_connect_status() == STATION_WRONG_PASSWORD ||
wifi_station_get_connect_status() == STATION_NO_AP_FOUND ||
wifi_station_get_connect_status() == STATION_CONNECT_FAIL))
{
os_printf("connect fail !!!
");
}
else
{
//re-arm timer to check ip
os_timer_setfn(&test_timer, (os_timer_func_t *)user_check_ip, NULL);
os_timer_arm(&test_timer, 100, 0);
}
}
}