Sasapea's Lab

ESPのESP8266WifiMulti/WiFiMultiはバージョンにより仕様が異なっている。古いバージョンでは非同期処理であったのが新しいバージョンではタイムアウト指定する同期処理となってしまった。そのため比較的長いタイムアウト時間を待つ必要があり、何らかの制御を行っているプログラムでは制御に時間的な問題が発生してしまう。非同期でも処理できたはずなのになんで同期処理に仕様変更してしまったのか通信系だけのアプリならありかもしれないが理解不能だ。

ということで同じような機能を自分で実装してみた。WiFi.status()の戻り値によりスキャン＆接続を非同期で処理する。スキャンで検出したAPのRSSI順に接続を試行し全て失敗した場合、或いは、接続が成功した後に接続が失われた場合は再度スキャンから始まる仕様だ。

比較的単純な処理であるものの非同期処理特有の難しさも少しあったりはするが、それなりに実装できたのではないかと思う。

【概要】

std::vector<String>& ssid(std::vector<String>& names)

1	std::vector<String>& ssid(std::vector<String>& names)

add()で登録した接続情報のうちスキャン結果に含まれるSSIDのみを取得する。

bool timeouted(void)

1	bool timeouted(void)

接続試行の疑似的なタイムアウト状態を返す。add()で何も登録されてない場合の初回スキャン後、或いは、接続できない状態が3分以上続くとtrueを返すがスキャン動作には影響しない。

void clear(void)

1	void clear(void)

add()で登録した接続情報を消去する。

size_t size(void)

1	size_t size(void)

add()で登録した接続情報の数を取得する。

void add(const String& ssid, const String& pswd)

1	void add(const String& ssid, const String& pswd)

接続情報を登録する。

void begin(void)

1	void begin(void)

初期処理を行う。

wl_status_t handle(void)

1	wl_status_t handle(void)

スキャン＆接続をハンドリングする。戻り値としてWiFi.status()の値を返す。

【サンプル・スケッチ】

#include "espwmap.h"

void setup()
{
  ESPWMAP.add("ssid1", "pswd1");
  ESPWMAP.add("ssid2", "pswd2");
  ESPWMAP.begin();
}

void loop()
{
  if (ESPWMAP.handle() == WL_CONNECTED)
    // connected.
}

#include "espwmap.h"

void setup()

{

ESPWMAP.add("ssid1", "pswd1");

ESPWMAP.add("ssid2", "pswd2");

ESPWMAP.begin();

}

void loop()

{

if (ESPWMAP.handle() == WL_CONNECTED)

// connected.

}

【修正履歴】
2023-03-29
SDKのタイムアウト値のコードミス？により特定のリビジョンのESP32C3でスキャンが失敗する場合があることへの対応。

【ライブラリ】

/*
  espmwap.h - WiFi Multi AP Library for ESP8266/ESP32

  Copyright (c) 2023 Sasapea's Lab. All right reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General
  Public License along with this library; if not, write to the
  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA
*/
#ifndef __ESPWMAP_H
#define __ESPWMAP_H

#include <vector>
#if defined(ESP32)
  #include "WiFi.h"
#elif defined(ESP8266)
  #include "ESP8266WiFi.h"
  #define WiFiScanClass ESP8266WiFiScanClass
#else
  #error "not supported enviroment."
#endif

#define ESPWMAP_DEBUG 0
#define ESPWMAP_CONNECTION_TIMEOUT (3 * 60 * 1000) // ms

class ESPWMAPClass : private WiFiScanClass
{
  private:

    typedef struct
    {
      String ssid;
      String pswd;
      int32_t rssi;
    } ap_info_t;

    std::vector<ap_info_t>  _aplist;
    std::vector<ap_info_t>  _apscan;
    std::vector<ap_info_t*> _apnext;
    unsigned long _disconnect;
    bool _connecting;

    void complete(int scanCount)
    {
      _apscan.clear();
      for (size_t i = 0; i < (size_t)scanCount; ++i)
      {
        auto scan = _apscan.begin();
        for (; scan != _apscan.end(); ++scan)
        {
          if (scan->ssid.equalsIgnoreCase(SSID(i)))
          {
            if (scan->rssi < RSSI(i))
              scan->rssi = RSSI(i);
            break;
          }
        }
        if (scan == _apscan.end())
        {
          ap_info_t ap = {SSID(i).c_str(), "", RSSI(i)};
          _apscan.push_back(ap);
        }
      }
      std::sort(_apscan.begin(), _apscan.end(),
        [](ap_info_t a, ap_info_t b)
        {
          return a.rssi > b.rssi;
        }
      );
      scanDelete();
      _apnext.clear();
      for (auto scan = _apscan.begin(); scan != _apscan.end(); ++scan)
      {
        for (auto list = _aplist.begin(); list != _aplist.end(); ++list)
        {
          if (list->ssid.equalsIgnoreCase(scan->ssid))
          {
            list->rssi = scan->rssi;
            _apnext.push_back(&*list);
            break;
          }
        }
      }
    }

    ap_info_t* next(void)
    {
      ap_info_t* rv = NULL;
      auto ap = _apnext.begin();
      if (ap != _apnext.end())
      {
        rv = *ap;
        _apnext.erase(ap);
      }
      return rv;
    }

  public:

    ESPWMAPClass(void)
    : _connecting(false)
    {
      _disconnect = millis();
    }

    virtual ~ESPWMAPClass(void)
    {
    }

    std::vector<String>& ssid(std::vector<String>& names)
    {
      names.clear();
      for (auto ap = _apscan.begin(); ap != _apscan.end(); ++ap)
        names.push_back(ap->ssid);
      return names;
    }

    bool timeouted(void)
    {
      return millis() - _disconnect >= ESPWMAP_CONNECTION_TIMEOUT;
    }

    void clear(void)
    {
      _aplist.clear();
    }

    size_t size(void)
    {
      return _aplist.size();
    }

    void add(const String& ssid, const String& pswd)
    {
      for (size_t i = 0; i < _aplist.size(); ++i)
      {
        if (_aplist[i].ssid.equalsIgnoreCase(ssid))
        {
          _aplist[i].pswd = pswd;
          return;
        }
      }
      ap_info_t ap = {ssid, pswd, 0};
      _aplist.push_back(ap);
    }

    void begin(void)
    {
      WiFi.persistent(false);
      WiFi.mode(WIFI_STA);
      _connecting = false;
    }

    wl_status_t handle(void)
    {
      yield(); // Run System Task
      switch (WiFi.status())
      {
        case WL_CONNECTED:
          _apnext.clear();
          _disconnect = millis();
          _connecting = false;
          break;
        default:
          _connecting = false;
          /* Falls through. */
        case WL_IDLE_STATUS:
        case WL_DISCONNECTED:
          if (_connecting)
            break;
          int scan = scanComplete();
          if (scan >= 0)
          {
            complete(scan);
#if ESPWMAP_DEBUG
            Serial.printf("WiFi Scan End (%d/%d)\r\n", (int)_apnext.size(), (int)_apscan.size()); 
#endif
            if (size() == 0)
            {
              _disconnect = millis() - ESPWMAP_CONNECTION_TIMEOUT;
              break;
            }
          }
          ap_info_t* ap = next();
          if (ap)
          {
#if ESPWMAP_DEBUG
            Serial.printf("WiFi Begin (%s)\r\n", ap->ssid.c_str()); 
#endif
            _connecting = true;
            WiFi.begin(ap->ssid.c_str(), ap->pswd.c_str());
          }
          else if (scan != WIFI_SCAN_RUNNING)
          {
#if ESPWMAP_DEBUG
            Serial.println("\r\nWiFi Scan Start"); 
#endif
#if CONFIG_IDF_TARGET_ESP32C3
            scanNetworks(true, false, false, 500);
#else
            scanNetworks(true);
#endif
          }
          break;
      }
      return WiFi.status();
    }
};

extern ESPWMAPClass ESPWMAP;

#endif

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espmwap.h - WiFi Multi AP Library for ESP8266/ESP32

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General

Public License along with this library; if not, write to the

Free Software Foundation, Inc., 59 Temple Place, Suite 330,

Boston, MA 02111-1307 USA

#ifndef __ESPWMAP_H

#define __ESPWMAP_H

#include <vector>

#if defined(ESP32)

#include "WiFi.h"

#elif defined(ESP8266)

#include "ESP8266WiFi.h"

#define WiFiScanClass ESP8266WiFiScanClass

#else

#error "not supported enviroment."

#endif

#define ESPWMAP_DEBUG 0

#define ESPWMAP_CONNECTION_TIMEOUT (3 * 60 * 1000) // ms

class ESPWMAPClass : private WiFiScanClass

{

private:

typedef struct

{

String ssid;

String pswd;

int32_t rssi;

} ap_info_t;

std::vector<ap_info_t> _aplist;

std::vector<ap_info_t> _apscan;

std::vector<ap_info_t*> _apnext;

unsigned long _disconnect;

bool _connecting;

void complete(int scanCount)

{

_apscan.clear();

for (size_t i = 0; i < (size_t)scanCount; ++i)

{

auto scan = _apscan.begin();

for (; scan != _apscan.end(); ++scan)

{

if (scan->ssid.equalsIgnoreCase(SSID(i)))

{

if (scan->rssi < RSSI(i))

scan->rssi = RSSI(i);

break;

}

if (scan == _apscan.end())

{

ap_info_t ap = {SSID(i).c_str(), "", RSSI(i)};

_apscan.push_back(ap);

}

std::sort(_apscan.begin(), _apscan.end(),

[](ap_info_t a, ap_info_t b)

{

return a.rssi > b.rssi;

}

);

scanDelete();

_apnext.clear();

for (auto scan = _apscan.begin(); scan != _apscan.end(); ++scan)

{

for (auto list = _aplist.begin(); list != _aplist.end(); ++list)

{

if (list->ssid.equalsIgnoreCase(scan->ssid))

{

list->rssi = scan->rssi;

_apnext.push_back(&*list);

break;

}

ap_info_t* next(void)

{

ap_info_t* rv = NULL;

auto ap = _apnext.begin();

if (ap != _apnext.end())

{

rv = *ap;

_apnext.erase(ap);

}

return rv;

}

public:

ESPWMAPClass(void)

: _connecting(false)

{

_disconnect = millis();

}

virtual ~ESPWMAPClass(void)

{

}

std::vector<String>& ssid(std::vector<String>& names)

{

names.clear();

for (auto ap = _apscan.begin(); ap != _apscan.end(); ++ap)

names.push_back(ap->ssid);

return names;

}

bool timeouted(void)

{

return millis() - _disconnect >= ESPWMAP_CONNECTION_TIMEOUT;

}

void clear(void)

{

_aplist.clear();

}

size_t size(void)

{

return _aplist.size();

}

void add(const String& ssid, const String& pswd)

{

for (size_t i = 0; i < _aplist.size(); ++i)

{

if (_aplist[i].ssid.equalsIgnoreCase(ssid))

{

_aplist[i].pswd = pswd;

return;

}

ap_info_t ap = {ssid, pswd, 0};

_aplist.push_back(ap);

}

void begin(void)

{

WiFi.persistent(false);

WiFi.mode(WIFI_STA);

_connecting = false;

}

wl_status_t handle(void)

{

yield(); // Run System Task

switch (WiFi.status())

{

case WL_CONNECTED:

_apnext.clear();

_disconnect = millis();

_connecting = false;

break;

default:

_connecting = false;

/* Falls through. */

case WL_IDLE_STATUS:

case WL_DISCONNECTED:

if (_connecting)

break;

int scan = scanComplete();

if (scan >= 0)

{

complete(scan);

#if ESPWMAP_DEBUG

Serial.printf("WiFi Scan End (%d/%d)\r\n", (int)_apnext.size(), (int)_apscan.size());

#endif

if (size() == 0)

{

_disconnect = millis() - ESPWMAP_CONNECTION_TIMEOUT;

break;

}

ap_info_t* ap = next();

if (ap)

{

#if ESPWMAP_DEBUG

Serial.printf("WiFi Begin (%s)\r\n", ap->ssid.c_str());

#endif

_connecting = true;

WiFi.begin(ap->ssid.c_str(), ap->pswd.c_str());

}

else if (scan != WIFI_SCAN_RUNNING)

{

#if ESPWMAP_DEBUG

Serial.println("\r\nWiFi Scan Start");

#endif

#if CONFIG_IDF_TARGET_ESP32C3

scanNetworks(true, false, false, 500);

#else

scanNetworks(true);

#endif

}

break;

}

return WiFi.status();

}

};

extern ESPWMAPClass ESPWMAP;

#endif

/*
  espwmap.cpp - WiFi Multi AP Library for ESP8266/ESP32

  Copyright (c) 2023 Sasapea's Lab. All right reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General
  Public License along with this library; if not, write to the
  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA
*/
#include "espwmap.h"

ESPWMAPClass ESPWMAP;

espwmap.cpp - WiFi Multi AP Library for ESP8266/ESP32

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General

Public License along with this library; if not, write to the

Free Software Foundation, Inc., 59 Temple Place, Suite 330,

Boston, MA 02111-1307 USA

#include "espwmap.h"

ESPWMAPClass ESPWMAP;

投稿

ESP8266/ESP32用のMultiAPライブラリを作ってみた。