use malloc/free for WiFiManagerParameter* array instead of hard coding.

add alternate constructor to specifiy max parameter count
origional default constructor uses old hard codded value

README.md

@@ -204,6 +204,11 @@ You should also take a look at adding custom HTML to your form.
 - Save and load custom parameters to file system in json form [AutoConnectWithFSParameters](https://github.com/tzapu/WiFiManager/tree/master/examples/AutoConnectWithFSParameters)
 - *Save and load custom parameters to EEPROM* (not done yet)
 
+NOTE: if your need more than 10 (the default) custom parameters you will need to use the alternate constructor:
+```cpp
+WiFiManager wifiManager(15); // pass the number of params you will be adding
+```
+
 #### Custom IP Configuration
 You can set a custom IP for both AP (access point, config mode) and STA (station mode, client mode, normal project state)
 

WiFiManager.cpp

@@ -60,14 +60,37 @@ const char* WiFiManagerParameter::getCustomHTML() {
   return _customHTML;
 }
 
+
 WiFiManager::WiFiManager() {
+    init(WIFI_MANAGER_MAX_PARAMS);
+}
+
+WiFiManager::WiFiManager(int max_params) {
+    init(max_params);
+}
+
+void WiFiManager::init(int max_params)
+{
+    DEBUG_WM(F("setting max_params to:"));
+    DEBUG_WM(max_params);
+    _max_params = max_params;
+    _params = (WiFiManagerParameter**)malloc(_max_params * sizeof(WiFiManagerParameter*));
+}
+
+WiFiManager::~WiFiManager()
+{
+    if (_params != NULL)
+    {
+        DEBUG_WM(F("freeing allocated params!"));
+        free(_params);
+    }
 }
 
 void WiFiManager::addParameter(WiFiManagerParameter *p) {
-  if(_paramsCount + 1 > WIFI_MANAGER_MAX_PARAMS)
+  if(_paramsCount + 1 > _max_params)
   {
     //Max parameters exceeded!
-	DEBUG_WM("WIFI_MANAGER_MAX_PARAMS exceeded, increase number (in WiFiManager.h) before adding more parameters!");
+	DEBUG_WM("max_params value exceeded, use WiFiManager(int max_params) constructor with a larger value!");
 	DEBUG_WM("Skipping parameter with ID:");
 	DEBUG_WM(p->getID());
 	return;

WiFiManager.h

@@ -65,6 +65,8 @@ class WiFiManager
 {
   public:
     WiFiManager();
+    WiFiManager(int max_params);
+    ~WiFiManager();
 
     boolean       autoConnect();
     boolean       autoConnect(char const *apName, char const *apPassword = NULL);
@@ -119,6 +121,7 @@ class WiFiManager
 
     //const String  HTTP_HEAD = "<!DOCTYPE html><html lang=\"en\"><head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\"/><title>{v}</title>";
 
+    void          init(int max_params);
     void          setupConfigPortal();
     void          startWPS();
 
@@ -176,7 +179,8 @@ class WiFiManager
     void (*_apcallback)(WiFiManager*) = NULL;
     void (*_savecallback)(void) = NULL;
 
-    WiFiManagerParameter* _params[WIFI_MANAGER_MAX_PARAMS];
+    int                    _max_params;
+    WiFiManagerParameter** _params;
 
     template <typename Generic>
     void          DEBUG_WM(Generic text);