onConnect callback added

Author: emelianov

examples/TestCallback/TestCallback.ino

@@ -25,17 +25,23 @@ const int ledPin = D4; // Builtin ESP8266 LED
 //ModbusIP object
 ModbusIP mb;
 
-// Callback function
+// Callback function for write (set) Coil. Returns value to store.
 uint16_t cbLed(TRegister* reg, uint16_t val) {
   //Attach ledPin to LED_COIL register
   digitalWrite(ledPin, (val == 0xFF00));
   return val;
 }
+
+// Callback function for client connect. Returns true to allow connection.
+bool cbConn(IPAddress ip) {
+  Serial.println(ip);
+  return true;
+}
 
 void setup() {
   Serial.begin(74880);
 
-  WiFi.begin("ssid", "pass");
+  WiFi.begin("ssid", "password");
 
   while (WiFi.status() != WL_CONNECTED) {
     delay(500);
@@ -46,7 +52,8 @@ void setup() {
   Serial.println("WiFi connected");  
   Serial.println("IP address: ");
   Serial.println(WiFi.localIP());
-
+  
+  mb.onConnect(cbConn);   // Add callback on connection event
   mb.begin();
 
   pinMode(ledPin, OUTPUT);
@@ -57,4 +64,5 @@ void setup() {
 void loop() {
    //Call once inside loop() - all magic here
    mb.task();
-}
+   yield();
+}

src/ModbusIP_ESP8266.cpp

@@ -5,42 +5,29 @@
 */
 #include "ModbusIP_ESP8266.h"
 
-//ModbusIP::ModbusIP() {
-//
-//}
-
 void ModbusIP::begin() {
 	WiFiServer::begin();
-	for (uint8_t i = 0; i < TCP_MAX_CLIENTS; i++) {
+	for (uint8_t i = 0; i < TCP_MAX_CLIENTS; i++)
 		client[i] = WiFiClient();
-	}
 }
 
 void ModbusIP::task() {
 	for (uint8_t n = 0; n < TCP_MAX_CLIENTS; n++) {
 		if (!client[n] || !client[n].connected()) {
 			client[n] = available();
-			//if (client[n] && client[n].connected()) {
-			//	Serial.println(client[n].remoteIP());
-			//}
+			if (client[n] && client[n].connected()) {
+				if (cbConnect && !cbConnect(client[n].remoteIP())) {
+					client[n].stop();		// If callback returns false immediate close connection
+					continue;
+				}
+			}
 		}
 
-	int raw_len = 0;
+		int raw_len = 0;
 
-    	//if (client[n]) {
-		if (client[n] && client[n].connected()) {
-//		    for (int x = 0; x < 300; x++) { // Time to have data available
-//				if (client[n].available()) {
-//					while (client[n].available() > raw_len) {  //Computes data length
-						raw_len = client[n].available();
-//						delay(1);
-//					}
-//					break;
-//				}
-//				delay(10);				
-//			}
-		}
-				
+		if (client[n] && client[n].connected())
+			raw_len = client[n].available();
+
 		if (raw_len > 7) {
 			for (int i=0; i<7; i++)	_MBAP[i] = client[n].read(); //Get MBAP
 
@@ -69,12 +56,15 @@ void ModbusIP::task() {
 
 				client[n].write(sbuf, send_len);
 			}
-		#ifndef TCP_KEEP_ALIVE
+			#ifndef TCP_KEEP_ALIVE
 			client[n].stop();
-		#endif
+			#endif
 			free(_frame);
 			_len = 0;
 		}
-	//}
+	}
 }
+
+void ModbusIP::onConnect(cbModbusConnect cb = NULL) {
+	cbConnect = cb;
 }

src/ModbusIP_ESP8266.h

@@ -20,17 +20,22 @@
 #define TCP_KEEP_ALIVE
 #define TCP_MAX_CLIENTS	    4
 
+// Callback function Type
+typedef bool (*cbModbusConnect)(IPAddress ip);
+
 class ModbusIP : public Modbus, public WiFiServer {
     private:
-        byte _MBAP[7];
+    byte _MBAP[7];
 	#ifdef TCP_KEEP_ALIVE
 	WiFiClient client[TCP_MAX_CLIENTS];
 	#endif
+	cbModbusConnect cbConnect = NULL;
     public:
 	ModbusIP() : WiFiServer(MODBUSIP_PORT) {
 	}
 	void begin();
-        void task();
+    void task();
+    void onConnect(cbModbusConnect cb);
 };
 
 #endif //MODBUSIP_ESP8266_H