Multiple connection support

Author: emelianov

README.md

@@ -5,7 +5,7 @@ used in industrial automation and can be used in other areas, such as home autom
 
 The Modbus generally uses serial RS-232 or RS-485 as physical layer (then called Modbus Serial) and TCP/IP via Ethernet or WiFi (Modbus IP).
 
-In the current version the library allows the ESP8266 operate as a slave, supporting Modbus IP via wireless network. For more information about Modbus see:
+In the current version the library allows the ESP8266/ESP32 operate as a slave, supporting Modbus IP via wireless network. For more information about Modbus see:
 
 http://pt.wikipedia.org/wiki/Modbus http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b.pdf
 http://www.modbus.org/docs/Modbus_Messaging_Implementation_Guide_V1_0b.pdf
@@ -62,8 +62,7 @@ This README is under development, for now, see the examples of the library.
 
 ## Contributions
 
-https://github.com/emelinov/modbus-esp8266
-
+https://github.com/emelinov/modbus-esp8266<br>
 [email protected]
 
 Original version:

library.properties

@@ -2,8 +2,8 @@ name=modbus-esp8266
 version=0.1
 author=Andre Sarmento Barbosa
 maintainer=Alexander Emelianov<[email protected]>
-sentence=Modbus Library for ESP8266
-paragraph=This library allows your ESP8266 to communicate via Modbus protocol. The Modbus is a master-slave protocol used in industrial automation and can be used in other areas, such as home automation.
+sentence=Modbus Library for ESP8266/ESP32
+paragraph=This library allows your ESP8266/ESP32 to communicate via Modbus protocol. The Modbus is a master-slave protocol used in industrial automation and can be used in other areas, such as home automation.
 category=Communication
 url=https://github.com/emelianov/modbus-esp8266
 architectures=esp8266,esp32

src/Modbus.cpp

@@ -1,7 +1,6 @@
 /*
     Modbus.h - Header for Modbus Base Library
     Copyright (C) 2014 André Sarmento Barbosa
-                  2017 Alexander Emelianov ([email protected])
 */
 #include "Modbus.h"
 

src/Modbus.h

@@ -1,7 +1,6 @@
 /*
     Modbus.h - Header for Modbus Base Library
     Copyright (C) 2014 André Sarmento Barbosa
-                  2017 Alexander Emelianov ([email protected])
 */
 #include "Arduino.h"
 

src/ModbusIP_ESP8266.cpp

@@ -14,25 +14,19 @@ void ModbusIP::begin() {
 }
 
 void ModbusIP::task() {
-#ifdef TCP_KEEP_ALIVE
-	if (client == NULL || !client.connected()) {
-	//	if (client)
-	//		delete client;
-	//	
-			client = available();
-	}
-#else
-	WiFiClient client;
-#endif
+	for (uint8_t n = 0; n < TCP_MAX_CLIENTS; n++) {
+		if (!client[n] || !client[n].connected()) {
+			client[n] = available();
+		}
 
 	int raw_len = 0;
 
-    if (client) {
-		if (client.connected()) {
+    	if (client[n]) {
+		if (client[n].connected()) {
 		    for (int x = 0; x < 300; x++) { // Time to have data available
-				if (client.available()) {
-					while (client.available() > raw_len) {  //Computes data length
-						raw_len = client.available();
+				if (client[n].available()) {
+					while (client[n].available() > raw_len) {  //Computes data length
+						raw_len = client[n].available();
 						delay(1);
 					}
 					break;
@@ -42,7 +36,7 @@ void ModbusIP::task() {
 		}
 
 		if (raw_len > 7) {
-			for (int i=0; i<7; i++)	_MBAP[i] = client.read(); //Get MBAP
+			for (int i=0; i<7; i++)	_MBAP[i] = client[n].read(); //Get MBAP
 
 			_len = _MBAP[4] << 8 | _MBAP[5];
 			_len--; // Do not count with last byte from MBAP
@@ -51,10 +45,10 @@ void ModbusIP::task() {
 			_frame = (byte*) malloc(_len);
 
 			raw_len = raw_len - 7;
-			for (int i=0; i< raw_len; i++)	_frame[i] = client.read(); //Get Modbus PDU
+			for (int i=0; i< raw_len; i++)	_frame[i] = client[n].read(); //Get Modbus PDU
 
 			this->receivePDU(_frame);
-			client.flush();
+			client[n].flush();
 
 			if (_reply != MB_REPLY_OFF) {
 			    //MBAP
@@ -67,61 +61,14 @@ void ModbusIP::task() {
 				for (int i=0; i<7; i++)	    sbuf[i] = _MBAP[i];
 				for (int i=0; i<_len; i++)	sbuf[i+7] = _frame[i];
 
-				client.write(sbuf, send_len);
+				client[n].write(sbuf, send_len);
 			}
 		#ifndef TCP_KEEP_ALIVE
-			client.stop();
+			client[n].stop();
 		#endif
 			free(_frame);
 			_len = 0;
 		}
 	}
 }
-	/*
-    uint8_t buffer[128] = {0};
-    uint8_t mux_id;
-    uint32_t len = _wifi->recv(&mux_id, buffer, sizeof(buffer), 100);
-
-    if (len > 0) {
-        int i = 0;
-        while (i < 7) {
-            _MBAP[i] = buffer[i];
-             i++;
-        }
-
-        _len = _MBAP[4] << 8 | _MBAP[5];
-        _len--; // Do not count with last byte from MBAP
-        if (_MBAP[2] !=0 || _MBAP[3] !=0) return;   //Not a MODBUSIP packet
-        if (_len > MODBUSIP_MAXFRAME) return;      //Length is over MODBUSIP_MAXFRAME
-
-        _frame = (byte*) malloc(_len);
-        i = 0;
-        while (i < _len){
-            _frame[i] = buffer[7+i];  //Forget MBAP and take just modbus pdu
-            i++;
-        }
-
-        this->receivePDU(_frame);
-
-        if (_reply != MB_REPLY_OFF) {
-            //MBAP
-            _MBAP[4] = _len >> 8;
-            _MBAP[5] = _len | 0x00FF;
-            buffer[4] = _MBAP[4];
-            buffer[5] = _MBAP[5];
-
-            i = 0;
-            while (i < _len){
-                buffer[i+7] = _frame[i];
-                i++;
-            }
-            _wifi->send(mux_id, buffer, _len + 7);
-            _wifi->releaseTCP(mux_id);
-        }
-
-        free(_frame);
-        _len = 0;
-    }
-
-}
-*/
+}

src/ModbusIP_ESP8266.h

@@ -18,12 +18,13 @@
 #define MODBUSIP_TIMEOUT   10
 
 #define TCP_KEEP_ALIVE
+#define TCP_MAX_CLIENTS	    4
 
 class ModbusIP : public Modbus, public WiFiServer {
     private:
         byte _MBAP[7];
 	#ifdef TCP_KEEP_ALIVE
-	WiFiClient client;
+	WiFiClient client[TCP_MAX_CLIENTS];
 	#endif
     public:
 	ModbusIP() : WiFiServer(MODBUSIP_PORT) {