diff --git a/API.md b/API.md
index ded3b9c..0f952ef 100644
--- a/API.md
+++ b/API.md
@@ -117,6 +117,24 @@ LoRa.endPacket(async);
 
 Returns `1` on success, `0` on failure.
 
+### Tx Done
+
+**WARNING**: Not supported on the Arduino MKR WAN 1300 board! 
+
+### Register callback
+
+Register a callback function for when a packet transmission finish.
+
+```arduino
+LoRa.onTxDone(onTxDone);
+
+void onTxDone() {
+ // ...
+}
+```
+
+ * `onTxDone` - function to call when a packet transmission finish.
+
 ## Receiving data
 
 ### Parsing packet
diff --git a/keywords.txt b/keywords.txt
index 2cf0351..63e0e9a 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -31,6 +31,7 @@ peek	KEYWORD2
 flush	KEYWORD2
 
 onReceive	KEYWORD2
+onTxDone	KEYWORD2
 receive	KEYWORD2
 idle	KEYWORD2
 sleep	KEYWORD2
diff --git a/src/LoRa.cpp b/src/LoRa.cpp
index aef149c..6980f5a 100644
--- a/src/LoRa.cpp
+++ b/src/LoRa.cpp
@@ -70,7 +70,8 @@ LoRaClass::LoRaClass() :
   _frequency(0),
   _packetIndex(0),
   _implicitHeaderMode(0),
-  _onReceive(NULL)
+  _onReceive(NULL),
+  _onTxDone(NULL)
 {
   // overide Stream timeout value
   setTimeout(0);
@@ -177,13 +178,14 @@ int LoRaClass::beginPacket(int implicitHeader)
 
 int LoRaClass::endPacket(bool async)
 {
+  
+  if ((async) && (_onTxDone))
+      writeRegister(REG_DIO_MAPPING_1, 0x40); // DIO0 => TXDONE
+
   // put in TX mode
   writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_TX);
 
-  if (async) {
-    // grace time is required for the radio
-    delayMicroseconds(150);
-  } else {
+  if (!async) {
     // wait for TX done
     while ((readRegister(REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK) == 0) {
       yield();
@@ -353,8 +355,24 @@ void LoRaClass::onReceive(void(*callback)(int))
 
   if (callback) {
     pinMode(_dio0, INPUT);
+#ifdef SPI_HAS_NOTUSINGINTERRUPT
+    SPI.usingInterrupt(digitalPinToInterrupt(_dio0));
+#endif
+    attachInterrupt(digitalPinToInterrupt(_dio0), LoRaClass::onDio0Rise, RISING);
+  } else {
+    detachInterrupt(digitalPinToInterrupt(_dio0));
+#ifdef SPI_HAS_NOTUSINGINTERRUPT
+    SPI.notUsingInterrupt(digitalPinToInterrupt(_dio0));
+#endif
+  }
+}
 
-    writeRegister(REG_DIO_MAPPING_1, 0x00);
+void LoRaClass::onTxDone(void(*callback)())
+{
+  _onTxDone = callback;
+
+  if (callback) {
+    pinMode(_dio0, INPUT);
 #ifdef SPI_HAS_NOTUSINGINTERRUPT
     SPI.usingInterrupt(digitalPinToInterrupt(_dio0));
 #endif
@@ -369,6 +387,9 @@ void LoRaClass::onReceive(void(*callback)(int))
 
 void LoRaClass::receive(int size)
 {
+
+  writeRegister(REG_DIO_MAPPING_1, 0x00); // DIO0 => RXDONE
+
   if (size > 0) {
     implicitHeaderMode();
 
@@ -640,17 +661,28 @@ void LoRaClass::handleDio0Rise()
   writeRegister(REG_IRQ_FLAGS, irqFlags);
 
   if ((irqFlags & IRQ_PAYLOAD_CRC_ERROR_MASK) == 0) {
-    // received a packet
-    _packetIndex = 0;
 
-    // read packet length
-    int packetLength = _implicitHeaderMode ? readRegister(REG_PAYLOAD_LENGTH) : readRegister(REG_RX_NB_BYTES);
+    if ((irqFlags & IRQ_RX_DONE_MASK) != 0) {
+      // received a packet
+      _packetIndex = 0;
 
-    // set FIFO address to current RX address
-    writeRegister(REG_FIFO_ADDR_PTR, readRegister(REG_FIFO_RX_CURRENT_ADDR));
+      // read packet length
+      int packetLength = _implicitHeaderMode ? readRegister(REG_PAYLOAD_LENGTH) : readRegister(REG_RX_NB_BYTES);
 
-    if (_onReceive) {
-      _onReceive(packetLength);
+      // set FIFO address to current RX address
+      writeRegister(REG_FIFO_ADDR_PTR, readRegister(REG_FIFO_RX_CURRENT_ADDR));
+
+      if (_onReceive) {
+        _onReceive(packetLength);
+      }
+
+      // reset FIFO address
+      writeRegister(REG_FIFO_ADDR_PTR, 0);
+    }
+    else if ((irqFlags & IRQ_TX_DONE_MASK) != 0) {
+      if (_onTxDone) {
+        _onTxDone();
+      }
     }
   }
 }
diff --git a/src/LoRa.h b/src/LoRa.h
index 294f537..c1671c1 100644
--- a/src/LoRa.h
+++ b/src/LoRa.h
@@ -57,6 +57,7 @@ public:
 
 #ifndef ARDUINO_SAMD_MKRWAN1300
   void onReceive(void(*callback)(int));
+  void onTxDone(void(*callback)());
 
   void receive(int size = 0);
 #endif
@@ -117,6 +118,7 @@ private:
   int _packetIndex;
   int _implicitHeaderMode;
   void (*_onReceive)(int);
+  void (*_onTxDone)();
 };
 
 extern LoRaClass LoRa;