First commit

firmware/Modbus-Arduino/issues/modbus-arduino-Issue5/src/main.cpp

@@ -0,0 +1,41 @@
+#include <ModbusSerial.h>
+
+// Used Pins
+const byte LedPin = LED_BUILTIN;
+const byte TxenPin = -1;    // -1 disables the feature, change that if you are using an RS485 driver, this pin would be connected to the DE and /RE pins of the driver.
+
+#define MySerial Serial1  // define serial port used, Serial most of the time, or Serial1, Serial2 ... if available
+const unsigned long Baudrate = 38400;
+
+const byte SlaveId = 10;
+
+const byte FirstReg = 0;
+const byte Lamp1Coil = FirstReg;
+const byte NofRegs = 32;
+
+ModbusSerial mb(MySerial, SlaveId, TxenPin);
+
+void setup() {
+
+  // MySerial.begin(Baudrate);  // works on all boards but the configuration is 8N1 which is incompatible with the MODBUS standard
+  // prefer the line below instead if possible
+  MySerial.begin (Baudrate, MB_PARITY_EVEN);
+
+  mb.config(Baudrate);
+
+  for (byte i = 0; i < NofRegs; i++) {
+
+    mb.addHreg(FirstReg + i, i);
+    mb.addIreg(FirstReg + i, i);
+    mb.addCoil(FirstReg + i, i % 2);
+    mb.addIsts(FirstReg + i, (i + 1) % 2);
+  }
+
+  pinMode(LedPin, OUTPUT);
+}
+
+void loop() {
+
+  mb.task();
+  digitalWrite(LedPin, !mb.Coil(Lamp1Coil));
+}