Add callback assign methods, callback example

Author: emelianov

examples/TestCallback/TestCallback.ino

@@ -0,0 +1,60 @@
+/*
+  Modbus-Arduino Example - Test Led using callback (Modbus IP ESP8266/ESP32)
+  Control a Led on D4 pin using Write Single Coil Modbus Function 
+  Original library
+  Copyright by André Sarmento Barbosa
+  http://github.com/andresarmento/modbus-arduino
+
+  Current version
+  (c)2017 Alexander Emelianov ([email protected])
+  https://github.com/emelianov/modbus-esp8266
+*/
+
+#ifdef ESP8266
+ #include <ESP8266WiFi.h>
+#else
+ #include <WiFi.h>
+#endif
+#include <ModbusIP_ESP8266.h>
+
+//Modbus Registers Offsets (0-9999)
+const int LED_COIL = 100;
+//Used Pins
+const int ledPin = D4; // Builtin ESP8266 LED
+
+//ModbusIP object
+ModbusIP mb;
+
+// Callback function
+uint16_t cbLed(TRegister* reg, uint16_t val) {
+  //Attach ledPin to LED_COIL register
+  digitalWrite(ledPin, (val == 0xFF00));
+  return val;
+}
+ 
+void setup() {
+  Serial.begin(74880);
+ 
+  WiFi.begin("ssid", "pass");
+  
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(".");
+  }
+ 
+  Serial.println("");
+  Serial.println("WiFi connected");  
+  Serial.println("IP address: ");
+  Serial.println(WiFi.localIP());
+
+  mb.begin();
+
+  pinMode(ledPin, OUTPUT);
+  mb.addCoil(LED_COIL);     // Add Coil
+  mb.onSet(COIL(LED_COIL), cbLed); // Add callback on Coil LED_COIL value set
+}
+
+void loop() {
+   //Call once inside loop() - all magic here
+   mb.task();
+}

src/Modbus.cpp

@@ -1,6 +1,7 @@
 /*
     Modbus.h - Header for Modbus Base Library
     Copyright (C) 2014 André Sarmento Barbosa
+                  2017 Alexander Emelianov ([email protected])
 */
 #include "Modbus.h"
 
@@ -515,6 +516,23 @@ void Modbus::writeMultipleCoils(byte* frame,uint16_t startreg, uint16_t numoutpu
     _reply = MB_REPLY_NORMAL;
 }
 #endif
+bool Modbus::onGet(uint16_t address, cbModbus cb) {
+	TRegister* reg = this->searchRegister(address);
+	if (reg) {
+		reg->get = cb;
+		return true;
+	}
+	return false;
+}
+bool Modbus::onSet(uint16_t address, cbModbus cb) {
+	TRegister* reg = this->searchRegister(address);
+	if (reg) {
+		reg->set = cb;
+		return true;
+	}
+	return false;
+}
+
 
 
 

src/Modbus.h

@@ -1,18 +1,23 @@
 /*
     Modbus.h - Header for Modbus Base Library
     Copyright (C) 2014 André Sarmento Barbosa
+                  2017 Alexander Emelianov ([email protected])
 */
 #include "Arduino.h"
 
 #ifndef MODBUS_H
 #define MODBUS_H
 
-#define MAX_REGS      32
+#define MAX_REGS     32
 #define MAX_FRAME   128
 #define COIL_BASE     1
 #define ISTS_BASE 10001
 #define IREG_BASE 30001
 #define HREG_BASE 40001
+#define COIL(n) (n + COIL_BASE)
+#define ISTS(n) (n + ISTS_BASE)
+#define IREG(n) (n + IREG_BASE)
+#define HERG(n) (n + HREG_BASE)
 
 //#define USE_HOLDING_REGISTERS_ONLY
 
@@ -57,6 +62,8 @@ typedef struct TRegister {
     cbModbus set;
 } TRegister;
 
+uint16_t cbDefault(TRegister* reg, uint16_t val);
+
 class Modbus {
     private:
         TRegister *_regs_head;
@@ -106,6 +113,9 @@ class Modbus {
             bool Ists(uint16_t offset);
             uint16_t Ireg(uint16_t offset);
         #endif
+        
+        bool onGet(uint16_t address, cbModbus cb = cbDefault);
+        bool onSet(uint16_t address, cbModbus cb = cbDefault);
 };
 
 #endif //MODBUS_H