More configuration options

- wifi provisioning
- auto start/stop of sessions

firmware/lib/wifimanager/WifiManager.cpp

@@ -0,0 +1,105 @@
+#include "WifiManager.h"
+
+void WifiManager::begin(const String &hostname)
+{
+  hostname_ = hostname;
+  prefs_.begin("st_wifi_manager");
+  startWifi();
+}
+
+void WifiManager::startWifi()
+{
+  WiFi.disconnect();
+
+  const String apPassword = prefs_.getString("apPassword", "");
+  const String staSSID = prefs_.getString("staSSID", "");
+  const String staPassword = prefs_.getString("staPassword", "");
+
+  if (staSSID.length() > 0 && staPassword.length() > 0)
+  {
+    // station mode
+    WiFi.mode(WIFI_STA);
+    WiFi.begin(staSSID.c_str(), staPassword.c_str());
+    WiFi.setHostname(hostname_.c_str());
+    int connectCounter = 0;
+    bool successful = true;
+    while (WiFi.status() != WL_CONNECTED)
+    {
+      delay(2000);
+      WiFi.begin(staSSID.c_str(), staPassword.c_str());
+      connectCounter += 1;
+      if (connectCounter >= 60) // for two minutes no connection
+      {
+        successful = false;
+        break; // fallback to AP mode
+      }
+    }
+    state_ = STA;
+    if (successful)
+      return;
+  }
+
+  WiFi.mode(WIFI_AP);
+  WiFi.softAPConfig(IPAddress(192, 168, 42, 1), IPAddress(192, 168, 42, 1), IPAddress(255, 255, 255, 0));
+  WiFi.softAPsetHostname(hostname_.c_str());
+  if (apPassword.length() > 0)
+  {
+    WiFi.softAP(hostname_.c_str(), apPassword.c_str());
+    state_ = AP_SECURE;
+  }
+  else
+  {
+    WiFi.softAP(hostname_.c_str());
+    state_ = AP_PROVISIONING;
+  }
+}
+
+void WifiManager::setStaCredentials(const char *wifiName, const char *password)
+{
+  assert(state_ != INVALID);
+
+  prefs_.putString("staSSID", wifiName);
+  prefs_.putString("staPassword", password);
+}
+
+void WifiManager::setApCredentials(const char *password)
+{
+  assert(state_ != INVALID);
+
+  prefs_.remove("staSSID");
+  prefs_.remove("staPassword");
+  prefs_.putString("apPassword", password);
+}
+
+void WifiManager::resetToApProvisioning()
+{
+  prefs_.remove("apPassword");
+  prefs_.remove("staSSID");
+  prefs_.remove("staPassword");
+}
+
+void WifiManager::wifiWatchdog()
+{
+  if (state_ == STA && WiFi.status() != WL_CONNECTED) {
+    startWifi();
+    Serial.println("Connection lost - Restarting WIFI");
+  }
+}
+
+
+const char * WifiManager::stateToString(WifiManager::State state)
+{
+  switch (state)
+  {
+  case INVALID:
+    return "INVALID";
+  case STA:
+    return "STATION_MODE";
+  case AP_PROVISIONING:
+    return "AP_PROVISIONING";
+  case AP_SECURE:
+    return "AP_SECURE";
+  default:
+    return "";
+  };
+}

firmware/lib/wifimanager/WifiManager.h

@@ -0,0 +1,51 @@
+#pragma once
+
+#include "Preferences.h"
+#include <WiFi.h>
+
+/**
+ * Manages connection and provisioning of WiFI
+ * 
+ *  Starts in state AP_PROVISIONING, where device is an access point without password.
+ *  Device should not work normally in this mode, only API is served to set password.
+ *  Two options:
+ *    - connect to existing WiFi (station mode), via setStaCredentials
+ *    - create secured access point, via setApCredentials
+ *  
+ * When operating in access point mode, the device IP is 192.168.42.1
+ * 
+ * call wifiWatchdog regularly to reconnect in station mode if connection was lost
+ */
+class WifiManager
+{
+public:
+  enum State
+  {
+    INVALID,
+    STA,
+    AP_PROVISIONING,
+    AP_SECURE,
+  };
+  WifiManager() : state_(INVALID) {}
+
+  void begin(const String &hostname);
+
+  void setStaCredentials(const char *wifiName, const char *password);
+  void setApCredentials(const char *password);
+  void resetToApProvisioning();
+
+  void wifiWatchdog();
+
+  bool inProvisioningMode() const { return state_ == INVALID || state_ == AP_PROVISIONING; }
+
+  State state() const { return state_; }
+  const char *stateStr() const { return stateToString(state_); }
+
+  static const char *stateToString(State state);
+
+private:
+  void startWifi();
+  Preferences prefs_;
+  State state_;
+  String hostname_;
+};