Add example TX only code

examples/TX_only/TX_only.pde

@@ -0,0 +1,54 @@
+/**
+ * Example code for using a microchip mrf24j40 module to send simple packets
+ *
+ * Requirements: 3 pins for spi, 3 pins for reset, chip select and interrupt
+ * notifications
+ * This example file is considered to be in the public domain
+ * Originally written by Karl Palsson, karlp@tweak.net.au, March 2011
+ */
+#include <SPI.h>
+#include <mrf24j.h>
+
+const int pin_reset = 6;
+const int pin_cs = 7;
+const int pin_interrupt = 5;
+
+Mrf24j mrf(pin_reset, pin_cs, pin_interrupt);
+
+long last_time;
+long tx_interval = 1000;
+
+void setup() {
+  Serial.begin(9600);
+
+  mrf.set_pan(0xcafe);
+  // This is _our_ address
+  mrf.address16_write(0x6001); 
+
+  attachInterrupt(0, interrupt_routine, CHANGE);   
+
+  last_time = millis();
+  interrupts();
+}
+
+void interrupt_routine() {
+    // read and clear interrupt flags from the radio
+    byte last_interrupt = mrf.read_short(MRF_INTSTAT);
+    // we don't care about the rx acks, but we need them to be flushed so it can keep receiving
+    if (last_interrupt & MRF_I_RXIF) {
+        mrf.write_short(MRF_RXFLUSH, 0x01);
+    }
+}
+
+
+void loop() {
+    int tmp;
+    unsigned long current_time = millis();
+    if (current_time - last_time > tx_interval) {
+        last_time = current_time;
+        Serial.println("txxxing...");
+        char * msg = "hello world";
+        mrf.send16(0x4202, strlen(msg), msg);
+    }
+  
+}