diff --git a/src/RS485.cpp b/src/RS485.cpp
index 2f018e7..eb322ab 100644
--- a/src/RS485.cpp
+++ b/src/RS485.cpp
@@ -30,13 +30,25 @@ RS485Class::RS485Class(HardwareSerial& hwSerial, int txPin, int dePin, int rePin
 
 void RS485Class::begin(unsigned long baudrate)
 {
-  begin(baudrate, SERIAL_8N1);
+  begin(baudrate, SERIAL_8N1,RS485_DEFAULT_PRE_DELAY,RS485_DEFAULT_POST_DELAY);
+}
+
+void RS485Class::begin(unsigned long baudrate, int predelay, int postdelay)
+{
+  begin(baudrate, SERIAL_8N1,predelay,postdelay);
 }
 
 void RS485Class::begin(unsigned long baudrate, uint16_t config)
+{
+  begin(baudrate,config,RS485_DEFAULT_PRE_DELAY,RS485_DEFAULT_POST_DELAY);
+}
+
+void RS485Class::begin(unsigned long baudrate, uint16_t config, int predelay, int postdelay)
 {
   _baudrate = baudrate;
   _config = config;
+  _predelay = predelay;
+  _postdelay = postdelay;
 
   if (_dePin > -1) {
     pinMode(_dePin, OUTPUT);
@@ -107,7 +119,7 @@ void RS485Class::beginTransmission()
 {
   if (_dePin > -1) {
     digitalWrite(_dePin, HIGH);
-    delayMicroseconds(50);
+    if (_predelay) delayMicroseconds(_predelay);
   }
 
   _transmisionBegun = true;
@@ -118,7 +130,7 @@ void RS485Class::endTransmission()
   _serial->flush();
 
   if (_dePin > -1) {
-    delayMicroseconds(50);
+    if (_postdelay) delayMicroseconds(_postdelay);
     digitalWrite(_dePin, LOW);
   }
 
@@ -166,4 +178,4 @@ void RS485Class::setPins(int txPin, int dePin, int rePin)
   _rePin = rePin;
 }
 
-RS485Class RS485(SERIAL_PORT_HARDWARE, RS485_DEFAULT_TX_PIN, RS485_DEFAULT_DE_PIN, RS485_DEFAULT_RE_PIN);
+RS485Class RS485(SERIAL_PORT_HARDWARE, RS485_DEFAULT_TX_PIN, RS845_DEFAULT_DE_PIN, RS845_DEFAULT_RE_PIN);
diff --git a/src/RS485.h b/src/RS485.h
index 24b976f..d06f051 100644
--- a/src/RS485.h
+++ b/src/RS485.h
@@ -29,19 +29,25 @@
 #endif
 
 #ifdef __AVR__
-#define RS485_DEFAULT_DE_PIN 2
-#define RS485_DEFAULT_RE_PIN -1
+#define RS845_DEFAULT_DE_PIN 2
+#define RS845_DEFAULT_RE_PIN -1
 #else
-#define RS485_DEFAULT_DE_PIN A6
-#define RS485_DEFAULT_RE_PIN A5
+#define RS845_DEFAULT_DE_PIN A6
+#define RS845_DEFAULT_RE_PIN A5
 #endif
 
+
+#define RS485_DEFAULT_PRE_DELAY 50
+#define RS485_DEFAULT_POST_DELAY 50
+
 class RS485Class : public Stream {
   public:
     RS485Class(HardwareSerial& hwSerial, int txPin, int dePin, int rePin);
 
     virtual void begin(unsigned long baudrate);
     virtual void begin(unsigned long baudrate, uint16_t config);
+    virtual void begin(unsigned long baudrate, int predelay, int postdelay);
+    virtual void begin(unsigned long baudrate, uint16_t config, int predelay, int postdelay);
     virtual void end();
     virtual int available();
     virtual int peek();
@@ -66,6 +72,8 @@ class RS485Class : public Stream {
     int _txPin;
     int _dePin;
     int _rePin;
+    int _predelay;
+    int _postdelay;
 
     bool _transmisionBegun;
     unsigned long _baudrate;