本程序所用的单片机型号为：STM32F103RE
PB12端口为外接的WiFi模块电源开关，当PB12输出低电平时接通电源。WiFi模块的电源引脚VCC不可直接连接到电源上，必须要串联一组PNP三极管（或场效应管），并把基极接到PB12端口上，基极要接限流电阻。
注意：WM-G-MR-09模块的芯片组（Chip Set）就是Marvell 88W8686。 Keil5工程下载地址：https://pan.baidu.com/s/1oRABiuKBG9m7P8E0fhc8NA
代码说明：http://blog.csdn.net/ZLK1214/article/details/79278871
Windows下根据计算机名获取IP地址的C语言程序：http://blog.csdn.net/ZLK1214/article/details/79595245
STM32F103RE单片机利用外部中断和DMA获取OV2640摄像头拍摄的照片，并通过串口发送到电脑上的程序：https://blog.csdn.net/zlk1214/article/details/79559466
lwip2.0.3协议栈的无操作系统移植过程：https://blog.csdn.net/ZLK1214/article/details/80957863 工程下载之后，请一定要将路径中的中文去掉，否则Keil5有可能错误地提示打不开stm32f10x.h头文件，但工程能正常编译。 lwip协议栈本身只包含DHCP客户端，Ad hoc模式下可以用lwDHCP创建DHCP服务器：http://savannah.nongnu.org/projects/lwdhcp 此版本修复了上一个版本（20180312版）存在的一些问题，主要更新如下：
1. 添加了扫描热点时显示路由器速率的功能
2. 添加了显示收到的数据帧的信噪比（SNR）、噪声基底（Noise Floor）、优先级和速率的功能（WIFI_DISPLAY_PACKET_RXRATES选项）
3. 解决了WPA/WPA2认证时多次收到第三次握手包导致多次调用WiFi_AuthenticationCompleteHandler回调函数的问题
4. 将数据帧最大发送速率改为了54Mbps, 更新了WIFI_DEFAULT_TIMEOUT_CMDACK和WIFI_DEFAULT_TIMEOUT_DATAACK的值
5. 修复了DHCP长时间获取不到IP地址的问题
6. 添加了TCP、UDP速度测试功能
7. 修复了部分路由器上Group key handshake失败导致掉线的问题（但仍有部分路由器还有此问题）
8. 增大了WiFi模块复位的时间, 避免在WiFi_ShowCIS函数中陷入死循环
10. 增加了wifi_buffer_rx缓冲溢出检查功能，溢出时自动丢弃待接收数据，不影响后续数据的接收
11. 修复了sys_now()溢出导致超时重传判断失效的问题
修改的文件：ethernetif.c, WiFi.c, WiFi.h, common.c, common.h, main.c, WiFi_LowLevel.c 【勘误】
2018年7月8日：common.c中有一个宏RTC_USELSI。请确保单片机使用的RTC时钟源和该宏定义匹配，否则程序运行时会出问题。可以用下面的代码进行检测，时钟源不匹配时自动复位RTC。该代码应该放在rtc_init函数中PWR_BackupAccessCmd的下一排。 if (RCC->BDCR & RCC_BDCR_RTCEN) { #ifdef RTC_USELSI if ((RCC->BDCR & RCC_BDCR_RTCSEL) != RCC_RTCCLKSource_LSI) #else if ((RCC->BDCR & RCC_BDCR_RTCSEL) != RCC_RTCCLKSource_LSE) #endif { printf("RTC is already running and the clock source doesn't match RTC_USELSI! "); printf("Reset RTC! "); RCC_BackupResetCmd(ENABLE); RCC_BackupResetCmd(DISABLE); } } 2018年7月10日：WiFi.c中，WiFi_KeyMaterial函数里面for循环内给key[i].header.length赋值的那句话，key->key_len应该改为key[i].key_len才对。 key[i].header.length = sizeof(MrvlIETypes_KeyParamSet_t) - sizeof(key[i].header) - sizeof(key[i].key) + key[i].key_len; 2018年7月22日：WiFi_SendCommand函数中，memmove那一行应该改为： memmove(wifi_buffer_command, data, (size != 0) ? size : ((WiFi_SDIOFrameHeader *)data)->length); 否则当参数data!=NULL且data!=wifi_buffer_command且size=0时，函数不能正常工作。 2018年8月1日：测速器上位机程序中，network.c里面的network_find_ip函数中，freeaddrinfo函数调用的位置不对，因为传入的参数info始终为NULL，应该传入的是getaddrinfo从第四个参数返回的值。正确的代码为（https://blog.csdn.net/ZLK1214/article/details/79595245）中的方法二的代码 【补充说明】 程序中用netif_set_up和netif_set_down函数来通知lwip网卡是否已连上网，编写了一个set_netif函数来辅助打开/关闭DHCP，用netif_is_up函数判断网卡是否已连上网。其实这并不是很合适。因为lwip的netif_set_up/netif_set_down函数（对应NETIF_FLAG_UP标志）决定的是网卡是“已启用”还是“已禁用”，并不是用来通知网卡是否已连上网的。通知网卡是否连上网的函数是netif_set_link_up和netif_set_link_down（对应NETIF_FLAG_LINK_UP标志），这两个函数里面会自动通知DHCP网络发生了变化（dhcp_network_changed）。这时，程序中可以用netif_is_link_up函数判断是否已连上网。 具体修改： (1) low_level_init函数中netif->flags去掉NETIF_FLAG_LINK_UP（默认情况下无线网卡是没有连上网的） (2) mac_address_callback函数中netif_set_default后面加上netif_set_up(&wifi_88w8686);（无线网卡在lwip中始终是“启用”状态） (3) set_netif修改为： static void set_netif(struct netif *netif, uint8_t up) { if (up) { netif_set_link_up(netif); // 该函数会通知DHCP网络发生了变化 // DHCP需要在网卡第一次连上网的时候手动启用 #if LWIP_DHCP if (netif_dhcp_data(netif) == NULL) dhcp_start(netif); // 路由器中显示的DHCP客户名称在ethernetif_init函数中设置 #endif } else netif_set_link_down(netif); }   Wi-Fi模块电源引脚的连接方法：   程序支持连接无密码的热点以及WEP、WPA-PSK和WPA2-PSK认证类型的热点，加密方式支持TKIP和AES。
支持创建无密码或是带有WEP密码的ADHOC热点，ADHOC模式下不支持WPA和WPA2！     注意：虽然SDIO标准规定可以总线上可以接多张SD卡，但STM32单片机的SDIO接口只支持接一张卡，STM32F103芯片手册Datasheet（不是参考手册）中有声明：
The current version supports only one SD/SDIO/MMC4.2 card at any one time and a stack of MMC4.1 or previous.
如果想要同时使用WiFi模块和SD内存卡，建议SD内存卡采用SPI总线通信。 【程序运行截图】 连上路由器后DHCP分配得到IP地址：   下面是把WiFi模块固件写入单片机芯片Flash固定区域的程序（用于减少调试主程序时下载程序的时间）的运行结果： ’ 电脑上ping IP地址和计算机名： 通过计算机名在电脑上访问开发板上的HTTP服务器（lwip自带的httpd）： TCP/UDP测速结果（测速软件位于压缩包内，附C语言源代码）： 【程序运行结果（连接WPA2路由器）】 STM32F103RE SDIO 88W8686 RESPCMD63, RESP1_90ff8000 RESPCMD63, RESP1_90300000 Number of I/O Functions: 1 Memory Present: 0 Relative Card Address: 0x0001 Card selected! RESP1_00001e00 SDIO Clock: 24MHz [CIS] func=0, ptr=0x00008000 Product Information: Marvell 802.11 SDIO ID: 0B Manufacturer Code: 0x02df Manufacturer Information: 0x9103 Card Function Code: 0x0c System Initialization Bit Mask: 0x00 Maximum Block Size: 256 Maximum Transfer Rate Code: 0x32 [CIS] func=1, ptr=0x00008080 Card Function Code: 0x0c System Initialization Bit Mask: 0x00 Maximum Block Size: 256 Firmware is successfully downloaded! MAC Addr: 00:1A:6B:A4:AA:B4 SSID '10507', MAC B0:95:8E:04:2A:06, RSSI 51, Channel 6 Capability: 0x0431 (Security: WPA2, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 11.0Mbps 6.0Mbps 9.0Mbps 12.0Mbps 18.0Mbps SSID 'TP_LINK_PLC', MAC 30:FC:68:38:6E:2C, RSSI 71, Channel 6 Capability: 0x0031 (Security: WPA2, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 11.0Mbps 6.0Mbps 9.0Mbps 12.0Mbps 18.0Mbps SSID 'CDU', MAC D4:61:FE:71:36:D0, RSSI 78, Channel 6 Capability: 0x8421 (Security: Unsecured, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 6.0Mbps 9.0Mbps 11.0Mbps 12.0Mbps 18.0Mbps SSID 'xgxy666', MAC DC:FE:18:67:76:14, RSSI 77, Channel 6 Capability: 0x0031 (Security: WPA2, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 11.0Mbps 6.0Mbps 9.0Mbps 12.0Mbps 18.0Mbps SSID 'DWYHX', MAC 48:7D:2E:19:88:9D, RSSI 76, Channel 6 Capability: 0x0031 (Security: WPA2, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 11.0Mbps 6.0Mbps 9.0Mbps 12.0Mbps 18.0Mbps SSID 'TP-LINK_ORANGE', MAC B0:95:8E:05:82:CA, RSSI 58, Channel 11 Capability: 0x0431 (Security: WPA2, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 11.0Mbps 6.0Mbps 9.0Mbps 12.0Mbps 18.0Mbps SSID '', MAC D6:14:4B:6F:A6:0F, RSSI 68, Channel 11 Capability: 0x0621 (Security: Unsecured, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 11.0Mbps 18.0Mbps 24.0Mbps 36.0Mbps 54.0Mbps SSID 'CMCC-EDU', MAC D6:14:4B:6F:A6:0E, RSSI 68, Channel 11 Capability: 0x0621 (Security: Unsecured, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 11.0Mbps 18.0Mbps 24.0Mbps 36.0Mbps 54.0Mbps SSID 'TP-LINK_5B8E', MAC 50:FA:84:53:5B:8E, RSSI 75, Channel 12 Capability: 0x0401 (Security: Unsecured, Mode: Infrastructure) Rates: 1.0Mbps 2.0Mbps 5.5Mbps 11.0Mbps 9.0Mbps 18.0Mbps 36.0Mbps 54.0Mbps Scan finished! Waiting for authentication! Message 1 received! Message 2 sent! Message 3 received! Message 4 sent! Authenticated! [Send] len=350 PTK & GTK set! [Recv] len=316 [Send] len=350 [Recv] len=316 [Send] len=42 [Send] len=42 [Send] len=42 DHCP supplied address! IP address: 192.168.1.115 Subnet mask: 255.255.255.0 Default gateway: 192.168.1.1 DNS Server: 192.168.1.1 [Send] len=42 Not in cache! err=-5 [Recv] len=42 [Send] len=76 [Recv] len=235 DNS Found IP: 106.186.126.193 Connecting to 106.186.126.193... [Send] len=58 [Send] len=42 [Recv] len=58 Connected! err=0 Connection is successfully closed! [Send] len=54 [Recv] len=54 [Send] len=54 [Send] len=42 [Send] len=42 [Send] len=42 [Recv] len=159 [Recv] len=92 [Send] len=42 [Send] len=42 [Recv] len=42 [Send] len=104 [Recv] len=42 [Recv] len=42 [Send] len=42 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=54 [Recv] len=355 [Send] len=590 [Send] len=349 [Recv] len=54 [Send] len=54 [Recv] len=54 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=54 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=355 [Send] len=590 [Send] len=349 [Recv] len=54 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Recv] len=54 [Send] len=590 [Recv] len=355 [Send] len=590 [Send] len=349 [Recv] len=54 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=54 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=355 [Send] len=590 [Send] len=349 [Recv] len=54 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=355 [Send] len=590 [Send] len=349 [Recv] len=54 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=66 [Send] len=58 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=54 [Recv] len=355 [Send] len=590 [Send] len=349 [Recv] len=54 [Recv] len=54 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=54 [Send] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=355 [Send] len=590 [Send] len=349 [Recv] len=54 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=66 [Send] len=58 [Recv] len=54 [Send] len=304 [Recv] len=54 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=54 [Send] len=304 [Recv] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=54 [Recv] len=300 [Send] len=590 [Send] len=590 [Recv] len=54 [Send] len=590 [Recv] len=66 [Send] len=58 [Recv] len=54 [Send] len=304 [Recv] len=54 [Recv] len=54 [Recv] len=355 [Send] len=590 [Send] len=349 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=54 [Recv] len=54 [Recv] len=54 [Send] len=54 [Recv] len=66 [Send] len=58 [Recv] len=54 [Send] len=54 [Recv] len=54