本帖最后由 roc2two 于 2019-6-19 11:02 编辑
概述: 无线网络提供的WiFi热点,大部分都开放了SSID广播(WiFi热点也可以隐藏的),Scan WiFi的功能就是扫描出所有附近的WiFi热点的SSID信息,这样一来,客户端就可以根据需要选择不同的SSID连入对应的无线网络中。 Scan WiFi库提供了两种方式实现扫描过程: 同步扫描:通过单个函数在一次运行中完成,需要等待完成所有操作才能继续运行下面的操作。 异步扫描:把上面的过程分成几个步骤,每个步骤由一个单独函数完成,我们可以在扫描过程中执行其他任务。 ESP8266WiFiScan库ESP8266WiFiScan库,大家使用的时候只需要引入 1.scanNetworks —— 同步扫描周边有效wifi网络 函数说明: /**
* Start scan WiFi networks available
* @param async run in async mode(是否启动异步扫描)
* @param show_hidden show hidden networks(是否扫描隐藏网络)
* @param channel scan only this channel (0 for all channels)(是否扫描特定通道)
* @param ssid* scan for only this ssid (NULL for all ssid's)(是否扫描特定的SSID)
* [url=home.php?mod=space&uid=266161]@return[/url] Number of discovered networks
*/int8_t scanNetworks(bool async = false, bool show_hidden = false, uint8 channel = 0, uint8* ssid = NULL);
2.scanNetworks(async ) —— 异步扫描周边有效wifi网络函数说明: /**
* Start scan WiFi networks available
* @param async run in async mode(是否启动异步扫描)
* @param show_hidden show hidden networks(是否扫描隐藏网络)
* @param channel scan only this channel (0 for all channels)(是否扫描特定通道)
* @param ssid* scan for only this ssid (NULL for all ssid's)(是否扫描特定的SSID)
* [url=home.php?mod=space&uid=266161]@return[/url] Number of discovered networks
*/int8_t scanNetworks(bool async = false, bool show_hidden = false, uint8 channel = 0, uint8* ssid = NULL);
3.scanNetworksAsync —— 异步扫描周边wifi网络,并回调结果
函数说明: /**
* Starts scanning WiFi networks available in async mode
* @param onComplete the event handler executed when the scan is done
* @param show_hidden show hidden networks
*/void scanNetworksAsync(std::function<void(int)> onComplete, bool show_hidden = false);
4. scanComplete —— 检测异步扫描的结果函数说明: /**
* called to get the scan state in Async mode(异步扫描的结果函数)
* @return scan result or status
* -1 if scan not find
* -2 if scan not triggered
*/
int8_t scanComplete();
5.scanDelete —— 从内存中删掉最近扫描结果函数说明: /**
* delete last scan result from RAM(从内存中删除最近的扫描结果)
*/void scanDelete();
扫描结果方法1. SSID —— 获取wifi网络名字函数说明: /**
* Return the SSID discovered during the network scan.
* @param i specify from which network item want to get the information
* @return ssid string of the specified item on the networks scanned list
*/String SSID(uint8_t networkItem);
2.RSSI —— 获取wifi网络信号强度函数说明: /**
* Return the RSSI of the networks discovered during the scanNetworks(信号强度)
* @param i specify from which network item want to get the information
* @return signed value of RSSI of the specified item on the networks scanned list
*/int32_t RSSI(uint8_t networkItem);
3. encryptionType —— 获取wifi网络加密方式函数说明: /**
* Return the encryption type of the networks discovered during the scanNetworks(加密方式)
* @param i specify from which network item want to get the information
* @return encryption type (enum wl_enc_type) of the specified item on the networks scanned list
* ............ Values map to 802.11 encryption suites.....................
* AUTH_OPEN ----> ENC_TYPE_WEP = 5,
* AUTH_WEP ----> ENC_TYPE_TKIP = 2,
* AUTH_WPA_PSK ----> ENC_TYPE_CCMP = 4,
* ........... except these two, 7 and 8 are reserved in 802.11-2007.......
* AUTH_WPA2_PSK ----> ENC_TYPE_NONE = 7,
* AUTH_WPA_WPA2_PSK ----> ENC_TYPE_AUTO = 8
*/uint8_t encryptionType(uint8_t networkItem);
4. BSSID —— 获取wifi网络mac地址函数说明: /**
* return MAC / BSSID of scanned wifi (物理地址)
* @param i specify from which network item want to get the information
* @return uint8_t * MAC / BSSID of scanned wifi
*/uint8_t * BSSID(uint8_t networkItem);
/**
* return MAC / BSSID of scanned wifi (物理地址)
* @param i specify from which network item want to get the information
* @return uint8_t * MAC / BSSID of scanned wifi
*/String BSSIDstr(uint8_t networkItem);
5.getNetworkInfo —— 获取整体网络信息,名字,信号强度等函数说明: /**
* loads all infos from a scanned wifi in to the ptr parameters
* @param networkItem uint8_t
* @param ssid const char**
* @param encryptionType uint8_t *
* @param RSSI int32_t *
* @param BSSID uint8_t **
* @param channel int32_t *
* @param isHidden bool *
* @return (true if ok)
*/ bool getNetworkInfo(uint8_t networkItem, String &ssid, uint8_t &encryptionType, int32_t &RSSI, uint8_t* &BSSID, int32_t &channel, bool &isHidden);
6. channel —— 获取wifi网络通道号函数说明: /**
* return channel of scanned wifi(通道号)
*/int32_t channel(uint8_t networkItem);
7. isHidden —— 判断wifi网络是否是隐藏网络函数说明: /**
* return if the scanned wifi is Hidden (no SSID)(判断扫描到的wifi是否是隐藏wifi)
* @param networkItem specify from which network item want to get the information
* @return bool (true == hidden)
*/bool isHidden(uint8_t networkItem);
动手操作 多说不宜,实验是检验真理的唯一标准,下面我们就来实际操作一下吧。 打开零知开源开发工具,新建一个项目,输入以下代码,验证,上传。 测试demo: /**
* Demo:
* STA模式下,演示同步扫描Scan wifi功能
* [url=home.php?mod=space&uid=187600]@author[/url] 云上上云
* [url=home.php?mod=space&uid=212281]@date[/url] 2019/06/01
*/#include <ESP8266WiFi.h>
//以下三个定义为调试定义#define DebugBegin(baud_rate) Serial.begin(baud_rate)#define DebugPrintln(message) Serial.println(message)#define DebugPrint(message) Serial.print(message)
void setup() { //设置串口波特率,以便打印信息
DebugBegin(115200); //延时5s 为了演示效果
delay(5000); // 我不想别人连接我,只想做个站点
WiFi.mode(WIFI_STA); //断开连接
WiFi.disconnect();
delay(100);
DebugPrintln("Setup done");
}
void loop() {
DebugPrintln("scan start"); // 同步扫描,等待返回结果
int n = WiFi.scanNetworks();
DebugPrintln("scan done"); if (n == 0){
DebugPrintln("no networks found");
}else{
DebugPrint(n);
DebugPrintln(" networks found"); for (int i = 0; i < n; ++i){
DebugPrint(i + 1);
DebugPrint(": "); //打印wifi账号
DebugPrint(WiFi.SSID(i));
DebugPrint(",");
DebugPrint(String("Ch:")+WiFi.channel(i));
DebugPrint(",");
DebugPrint(WiFi.isHidden(i)?"hide":"show");
DebugPrint(" ("); //打印wifi信号强度
DebugPrint(WiFi.RSSI(i));
DebugPrint("dBm");
DebugPrint(")"); //打印wifi加密方式
DebugPrintln((WiFi.encryptionType(i) == ENC_TYPE_NONE)?"open":"*");
delay(10);
}
}
DebugPrintln(""); // 延时5s之后再次扫描
delay(5000);
}
测试结果(附近潜在的WiFi热点):它可以扫描完附件所有WiFi。
更多详细资料可到零知实验室官网免费获取。
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