【零知ESP8266】教程：WiFiScan库的使用
本帖最后由 lz-esp-link 于 2019-6-19 10:58 编辑概述无线网络提供的WiFi热点，大部分都开放了SSID广播，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，使用的时候只需要引入：
[*]#include<ESP8266WiFi.h>
[*]扫描操作方法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)
* @return 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)
* @return 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
* @returnsigned 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
* @returnencryption 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 ssidconst 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);
[*]测试demo：
[*]/**
* Demo：
* STA模式下，演示同步扫描Scan wifi功能
* @author 云上上云
* @date 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）：
[*]
[*]更多详细资料可到零知实验室官网免费获取。
[*]
[*]
[*]
[*]
请问这个怎么获取指定的rssi值呀
页:
[1]