[问答]

STM32F107+LWIP怎样判断网络已经连接成功或断开的？

问答对人有帮助，内容完整，我也想知道答案 0 我现在在使用STM32F107+LWIP+DP83848进行tcp通讯，如何判断网络已经连接成功或断开的？怎么样能够使STM32F107随时接入以太网都可以通讯，我的程序如下，求指点 void LwIP_Init(void) { struct ip_addr ipaddr; //IP地址 struct ip_addr netmask; //子掩码 struct ip_addr gw; //网关地址 uint8_t macaddress[6]={0,0,0,0,0,1}; //以太网控制器物理地址，即MAC地址 /* Initializes the dynamic memory heap defined by MEM_SIZE./ mem_init(); / Initializes the memory pools defined by MEMP_NUM_x./ memp_init(); #if LWIP_DHCP ipaddr.addr = 0; netmask.addr = 0; gw.addr = 0; #else IP4_ADDR(&ipaddr, 192, 168, 1, 200); IP4_ADDR(&netmask, 255, 255, 255, 0); IP4_ADDR(&gw, 192, 168, 1, 1); #endif Set_MAC_Address(macaddress); / - netif_add(struct netif netif, struct ip_addr ipaddr, struct ip_addr netmask, struct ip_addr gw, void state, err_t ( init)(struct netif netif), err_t ( input)(struct pbuf p, struct netif netif)) Adds your network interface to the netif_list. Allocate a struct netif and pass a pointer to this structure as the first argument. Give pointers to cleared ip_addr structures when using DHCP, or fill them with sane numbers otherwise. The state pointer may be NULL. The init function pointer must point to a initialization function for your ethernet netif interface. The following code illustrates it's use./ netif_add(&netif, &ipaddr, &netmask, &gw, NULL, ðernetif_init, ðernet_input); / Registers the default network interface./ netif_set_default(&netif); #if LWIP_DHCP / Creates a new DHCP client for this interface on the first call. Note: you must call dhcp_fine_tmr() and dhcp_coarse_tmr() at the predefined regular intervals after starting the client. You can peek in the netif->dhcp struct for the actual DHCP status./ dhcp_start(&netif); #endif / When the netif is fully configured this function must be called./ netif_set_up(&netif); tcp_client_init(); } /* * @brief Called when a frame is received * @param None * @retval None / void LwIP_Pkt_Handle(void) { / Read a received packet from the Ethernet buffers and send it to the lwIP for handling / ethernetif_input(&netif); } /* * @brief LwIP periodic tasks * @param localtime the current LocalTime value * @retval None / void LwIP_Periodic_Handle(__IO uint32_t localtime) { / TCP periodic process every 250 ms / if (localtime - TCPTimer >= TCP_TMR_INTERVAL) { TCPTimer = localtime; tcp_tmr(); } / ARP periodic process every 5s / if (localtime - ARPTimer >= ARP_TMR_INTERVAL) { ARPTimer = localtime; etharp_tmr(); } #if LWIP_DHCP / Fine DHCP periodic process every 500ms / if (localtime - DHCPfineTimer >= DHCP_FINE_TIMER_MSECS) { DHCPfineTimer = localtime; dhcp_fine_tmr(); } / DHCP Coarse periodic process every 60s / if (localtime - DHCPcoarseTimer >= DHCP_COARSE_TIMER_MSECS) { DHCPcoarseTimer = localtime; dhcp_coarse_tmr(); } #endif } /* * @brief LCD & LEDs periodic handling * @param localtime: the current LocalTime value * @retval None / void Display_Periodic_Handle(__IO uint32_t localtime) { / 250 ms / if (localtime - DisplayTimer >= LCD_TIMER_MSECS) { DisplayTimer = localtime; #if LWIP_DHCP / We have got a new IP address so update the display / if (IPaddress != netif.ip_addr.addr) { / Read the new IP address / IPaddress = netif.ip_addr.addr; / Display the new IP address / if (netif.flags & NETIF_FLAG_DHCP) { tcp_client_init(); } } else if (IPaddress == 0) { / If no response from a DHCP server for MAX_DHCP_TRIES times / / stop the dhcp client and set a static IP address / if (netif.dhcp->tries > MAX_DHCP_TRIES) { struct ip_addr ipaddr; struct ip_addr netmask; struct ip_addr gw; dhcp_stop(&netif); IP4_ADDR(&ipaddr, 192, 168, 1, 8); IP4_ADDR(&netmask, 255, 255, 255, 201); IP4_ADDR(&gw, 192, 168, 1, 1); netif_set_addr(&netif, &ipaddr , &netmask, &gw); } } #endif } } void tcp_client_init(void) { struct tcp_PCB tpcb; struct ip_addr ipaddr; IP4_ADDR(&ipaddr, 192, 168, 1, 125); //远程主机 /* Create a new TCP control block / tpcb = tcp_new(); / Assign to the new pcb a local IP address and a port number / tcp_bind(tpcb, IP_ADDR_ANY, TCP_PORT); / Connect to the server: send the SYN / tcp_connect(tpcb, &ipaddr, TCP_PORT, tcp_client_accept); } /* * @brief This funtion is called when a TCP connection has been established on the port TCP_PORT. * @param arg user supplied argument * @param pcb the tcp_pcb which accepted the connection * @param err error value * @retval ERR_OK / err_t tcp_client_accept(void arg, struct tcp_pcb tpcb, err_t err) { / Specify the function that should be called when the TCP connection receives data / tcp_recv(tpcb, tcp_client_recv); return ERR_OK; } /* * @brief This function is called when a data is received over the TCP_PORT. * The received data contains the number of the led to be toggled. * @param arg user supplied argument * @param pcb the tcp_pcb which accepted the connection * @param p the packet buffer that was received * @param err error value * @retval ERR_OK / static err_t tcp_client_recv(void arg, struct tcp_pcb tpcb, struct pbuf p, err_t err) { uint8_t Data_len; /* Inform TCP that we have taken the data. / tcp_recved(tpcb, p->tot_len); Data_len = p->len; memcpy(RX, p->payload, Data_len); tcp_write(tpcb,&LocalDisplay,sizeof(LocalDisplay),1); / Free the p buffer */ pbuf_free(p); return ERR_OK; } 1
2014-3-26 16:45:17　　评论淘帖0 邀请回答您可以邀请以下用户，快速回答问题 × 嵌入式-H 该类别下有 16 个回答。邀请回答 hgimtk 该类别下有 16 个回答。邀请回答 dianzijie5 该类别下有 16 个回答。邀请回答 hucc 该类别下有 14 个回答。邀请回答舍我其谁84 该类别下有 13 个回答。邀请回答 HCPcry 该类别下有 12 个回答。邀请回答冰箱洗衣机该类别下有 12 个回答。邀请回答学生物的程序猿该类别下有 11 个回答。邀请回答小刘该类别下有 11 个回答。邀请回答 sjjs001 该类别下有 11 个回答。邀请回答 iettke 该类别下有 11 个回答。邀请回答 YOYOOO 该类别下有 10 个回答。邀请回答 bigbangboom 该类别下有 10 个回答。邀请回答 wuli北该类别下有 9 个回答。邀请回答 zengweishuai 该类别下有 9 个回答。邀请回答广州洋钒该类别下有 9 个回答。邀请回答 drakannie 该类别下有 9 个回答。邀请回答 siyugege 该类别下有 9 个回答。邀请回答 ze55me 该类别下有 8 个回答。邀请回答罗崇军该类别下有 8 个回答。邀请回答举报刀马旦相关推荐 • 请问STM32F107+LWIP如何检查tcp通讯断开并重新连接? 8101 • STM32F407作为tcp通讯客户端，如何判断网络已经连接成功或者网络是断开的？ 8339 • 使用正常的window API接口实现的程序连接上服务器就断开了 1735 • STM32F107可以通过LWIP连接网络时间服务器获取时间吗? 1936 • stm32f107 lwip 出现内存分配失败 3617 • 为什么STM32F107+LWIP在Linux系统下可以ping通但在win7系统下ping不通？ 1363 • 在stm32F107上移植Lwip不能ping通的原因有哪些 975 • 使用STM32F103R8T6+ENC28J60+LWIP作网络通讯，CAN发送失败了怎么解决？ 169 • STM32F107是怎样通过LWIP实现MQTT发布和订阅框架的呢 1935 • 为什么基于LWIP的TCP断开再连接反复大概十次后就连接不上了？ 5946 4个回答

答案对人有帮助，有参考价值 0 楼主可以试试这样的解决过程： 1.检查TCP是否断开：if(pcb->state==CLOSED){} 2.关闭之前的pcb：tcp_abort(client_pcb)； 3.重新连接TCP：tcp_client_connect()；

2014-3-26 16:47:06 评论举报二霸

答案对人有帮助，有参考价值 0 同意楼上，有一些标志位，可以判断是否断网，连接上网络等

2014-3-29 09:20:16 评论举报愤怒的企鹅