Merge pull request #17 from gabrielsan/master

minor fixes when using softserial

ModbusRtu.h

@@ -5,6 +5,7 @@
  * @author 	Samuel Marco i Armengol
  * @contact     [email protected]
  * @contribution Helium6072
+ * @contribution gabrielsan
  *
  * @description
  *  Arduino library for communicating with Modbus devices
@@ -167,7 +168,7 @@ class Modbus
     uint16_t *au16regs;
     uint16_t u16InCnt, u16OutCnt, u16errCnt;
     uint16_t u16timeOut;
-    uint32_t u32time, u32timeOut;
+    uint32_t u32time, u32timeOut, u32overTime;
     uint8_t u8regsize;
 
     void init(uint8_t u8id, uint8_t u8serno, uint8_t u8txenpin);
@@ -194,9 +195,9 @@ class Modbus
     Modbus(uint8_t u8id);
     void begin(long u32speed);
     void begin(SoftwareSerial *sPort, long u32speed);
-    void begin(long u32speed, uint8_t u8config);
+    //void begin(long u32speed, uint8_t u8config);
     void begin();
-    void setTimeOut( uint16_t u16timeout); //!<write communication watch-dog timer
+    void setTimeOut( uint16_t u16timeOut); //!<write communication watch-dog timer
     uint16_t getTimeOut(); //!<get communication watch-dog timer value
     boolean getTimeOutState(); //!<get communication watch-dog timer state
     int8_t query( modbus_t telegram ); //!<only for master
@@ -209,6 +210,7 @@ class Modbus
     uint8_t getState();
     uint8_t getLastError(); //!<get last error message
     void setID( uint8_t u8id ); //!<write new ID for the slave
+    void setTxendPinOverTime( uint32_t u32overTime );
     void end(); //!<finish any communication and release serial communication port
 };
 
@@ -372,7 +374,7 @@ void Modbus::begin(SoftwareSerial *sPort, long u32speed)
  * @param config  data frame settings (data length, parity and stop bits)
  * @ingroup setup
  */
-void Modbus::begin(long u32speed,uint8_t u8config)
+/* void Modbus::begin(long u32speed,uint8_t u8config)
 {
 
     switch( u8serno )
@@ -411,7 +413,7 @@ void Modbus::begin(long u32speed,uint8_t u8config)
     while(port->read() >= 0);
     u8lastRec = u8BufferSize = 0;
     u16InCnt = u16OutCnt = u16errCnt = 0;
-}
+} */
 
 /**
  * @brief
@@ -443,6 +445,21 @@ void Modbus::setID( uint8_t u8id)
     }
 }
 
+/**
+ * @brief
+ * Method to write the overtime count for txend pin.
+ * It waits until count reaches 0 after the transfer is done.
+ * With this, you can extend the time between txempty and
+ * the falling edge if needed.
+ *
+ * @param 	uint32_t	overtime count for txend pin
+ * @ingroup setup
+ */
+void Modbus::setTxendPinOverTime( uint32_t u32overTime )
+{
+    this->u32overTime = u32overTime;
+}
+
 /**
  * @brief
  * Method to read current slave ID address
@@ -481,7 +498,7 @@ void Modbus::setTimeOut( uint16_t u16timeOut)
  */
 boolean Modbus::getTimeOutState()
 {
-    return (millis() > u32timeOut);
+    return ((unsigned long)(millis() -u32timeOut) > (unsigned long)u16timeOut);
 }
 
 /**
@@ -668,7 +685,7 @@ int8_t Modbus::poll()
     else
         u8current = softPort->available();
 
-    if (millis() > u32timeOut)
+    if ((unsigned long)(millis() -u32timeOut) > (unsigned long)u16timeOut)
     {
         u8state = COM_IDLE;
         u8lastError = NO_REPLY;
@@ -682,10 +699,10 @@ int8_t Modbus::poll()
     if (u8current != u8lastRec)
     {
         u8lastRec = u8current;
-        u32time = millis() + T35;
+        u32time = millis();
         return 0;
     }
-    if (millis() < u32time) return 0;
+    if ((unsigned long)(millis() -u32time) < (unsigned long)T35) return 0;
 
     // transfer Serial buffer frame to auBuffer
     u8lastRec = 0;
@@ -764,10 +781,10 @@ int8_t Modbus::poll( uint16_t *regs, uint8_t u8size )
     if (u8current != u8lastRec)
     {
         u8lastRec = u8current;
-        u32time = millis() + T35;
+        u32time = millis();
         return 0;
     }
-    if (millis() < u32time) return 0;
+    if ((unsigned long)(millis() -u32time) < (unsigned long)T35) return 0;
 
     u8lastRec = 0;
     int8_t i8state = getRxBuffer();
@@ -790,7 +807,7 @@ int8_t Modbus::poll( uint16_t *regs, uint8_t u8size )
         return u8exception;
     }
 
-    u32timeOut = millis() + long(u16timeOut);
+    u32timeOut = millis();
     u8lastError = 0;
 
     // process message
@@ -827,9 +844,10 @@ int8_t Modbus::poll( uint16_t *regs, uint8_t u8size )
 void Modbus::init(uint8_t u8id, uint8_t u8serno, uint8_t u8txenpin)
 {
     this->u8id = u8id;
-    this->u8serno = (u8serno > 3) ? 0 : u8serno;
+    this->u8serno = u8serno;
     this->u8txenpin = u8txenpin;
     this->u16timeOut = 1000;
+    this->u32overTime = 0;
 }
 
 void Modbus::init(uint8_t u8id)
@@ -838,6 +856,7 @@ void Modbus::init(uint8_t u8id)
     this->u8serno = 4;
     this->u8txenpin = 0;
     this->u16timeOut = 1000;
+    this->u32overTime = 0;
 }
 
 /**
@@ -902,72 +921,28 @@ void Modbus::sendTxBuffer()
     u8BufferSize++;
     au8Buffer[ u8BufferSize ] = u16crc & 0x00ff;
     u8BufferSize++;
-
-    // set RS485 transceiver to transmit mode
+
     if (u8txenpin > 1)
     {
-        switch( u8serno )
-        {
-#if defined(UBRR1H)
-        case 1:
-            UCSR1A=UCSR1A |(1 << TXC1);
-            break;
-#endif
-
-#if defined(UBRR2H)
-        case 2:
-            UCSR2A=UCSR2A |(1 << TXC2);
-            break;
-#endif
-
-#if defined(UBRR3H)
-        case 3:
-            UCSR3A=UCSR3A |(1 << TXC3);
-            break;
-#endif
-        case 0:
-        default:
-            UCSR0A=UCSR0A |(1 << TXC0);
-            break;
-        }
+        // set RS485 transceiver to transmit mode
         digitalWrite( u8txenpin, HIGH );
     }
 
     // transfer buffer to serial line
-    if(u8serno<4)
+    if (u8serno < 4)
         port->write( au8Buffer, u8BufferSize );
     else
         softPort->write( au8Buffer, u8BufferSize );
 
-    // keep RS485 transceiver in transmit mode as long as sending
     if (u8txenpin > 1)
     {
-        switch( u8serno )
-        {
-#if defined(UBRR1H)
-        case 1:
-            while (!(UCSR1A & (1 << TXC1)));
-            break;
-#endif
-
-#if defined(UBRR2H)
-        case 2:
-            while (!(UCSR2A & (1 << TXC2)));
-            break;
-#endif
-
-#if defined(UBRR3H)
-        case 3:
-            while (!(UCSR3A & (1 << TXC3)));
-            break;
-#endif
-        case 0:
-        default:
-            while (!(UCSR0A & (1 << TXC0)));
-            break;
-        }
-
+        // must wait transmission end before changing pin state
+        // soft serial does not need it since it is blocking
+        if (u8serno < 4)
+            port->flush();
         // return RS485 transceiver to receive mode
+        volatile uint32_t u32overTimeCountDown = u32overTime;
+        while ( u32overTimeCountDown-- > 0);
         digitalWrite( u8txenpin, LOW );
     }
     if(u8serno<4)
@@ -978,7 +953,7 @@ void Modbus::sendTxBuffer()
     u8BufferSize = 0;
 
     // set time-out for master
-    u32timeOut = millis() + (unsigned long) u16timeOut;
+    u32timeOut = millis();
 
     // increase message counter
     u16OutCnt++;