non blocking functions added (#62)

.travis.yml

@@ -33,5 +33,6 @@ script:
       buildExampleSketch LoRaReceiverCallback;
     fi
   - buildExampleSketch LoRaSender
+  - buildExampleSketch LoRaSenderNonBlocking
   - buildExampleSketch LoRaSetSpread
   - buildExampleSketch LoRaSetSyncWord

API.md

@@ -82,7 +82,7 @@ LoRa.beginPacket(implicitHeader);
 
  * `implicitHeader` - (optional) `true` enables implicit header mode, `false` enables explicit header mode (default)
 
-Returns `1` on success, `0` on failure.
+Returns `1` if radio is ready to transmit, `0` if busy or on failure.
 
 ### Writing
 
@@ -109,8 +109,11 @@ Returns the number of bytes written.
 End the sequence of sending a packet.
 
 ```arduino
-LoRa.endPacket()
+LoRa.endPacket();
+
+LoRa.endPacket(async);
 ```
+ * `async` - (optional) `true` enables non-blocking mode, `false` waits for transmission to be completed (default)
 
 Returns `1` on success, `0` on failure.
 

examples/LoRaSenderNonBlocking/LoRaSenderNonBlocking.ino

@@ -0,0 +1,35 @@
+#include <SPI.h>
+#include <LoRa.h>
+
+int counter = 0;
+
+void setup() {
+  Serial.begin(9600);
+  while (!Serial);
+
+  Serial.println("LoRa Sender non-blocking");
+
+  if (!LoRa.begin(915E6)) {
+    Serial.println("Starting LoRa failed!");
+    while (1);
+  }
+}
+
+void loop() {
+  // wait until the radio is ready to send a packet
+  while (LoRa.beginPacket() == 0) {
+    Serial.print("waiting for radio ... ");
+    delay(100);
+  }
+
+  Serial.print("Sending packet non-blocking: ");
+  Serial.println(counter);
+
+  // send in async / non-blocking mode
+  LoRa.beginPacket();
+  LoRa.print("hello ");
+  LoRa.print(counter);
+  LoRa.endPacket(true); // true = async / non-blocking mode
+
+  counter++;
+}

src/LoRa.cpp

@@ -149,6 +149,10 @@ void LoRaClass::end()
 
 int LoRaClass::beginPacket(int implicitHeader)
 {
+  if (isTransmitting()) {
+    return 0;
+  }
+
   // put in standby mode
   idle();
 
@@ -165,22 +169,40 @@ int LoRaClass::beginPacket(int implicitHeader)
   return 1;
 }
 
-int LoRaClass::endPacket()
+int LoRaClass::endPacket(bool async)
 {
   // put in TX mode
   writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_TX);
 
-  // wait for TX done
-  while ((readRegister(REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK) == 0) {
-    yield();
+  if (async) {
+    // grace time is required for the radio
+    delayMicroseconds(150);
+  } else {
+    // wait for TX done
+    while ((readRegister(REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK) == 0) {
+      yield();
+    }
+    // clear IRQ's
+    writeRegister(REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);
   }
 
-  // clear IRQ's
-  writeRegister(REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);
-
   return 1;
 }
 
+bool LoRaClass::isTransmitting()
+{
+  if ((readRegister(REG_OP_MODE) & MODE_TX) == MODE_TX) {
+    return true;
+  }
+
+  if (readRegister(REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK) {
+    // clear IRQ's
+    writeRegister(REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);
+  }
+
+  return false;
+}
+
 int LoRaClass::parsePacket(int size)
 {
   int packetLength = 0;

src/LoRa.h

@@ -32,7 +32,7 @@ public:
   void end();
 
   int beginPacket(int implicitHeader = false);
-  int endPacket();
+  int endPacket(bool async = false);
 
   int parsePacket(int size = 0);
   int packetRssi();
@@ -88,6 +88,7 @@ private:
   void implicitHeaderMode();
 
   void handleDio0Rise();
+  bool isTransmitting();
 
   int getSpreadingFactor();
   long getSignalBandwidth();