Add more examples.

libraries/Dragino/examples/Basic/HC-SR04/HC-SR04.ino

@@ -0,0 +1,41 @@
+/*
+  HC-SR04_TEST :
+    Use SR04 ultro sonic sensor to measure distance and show it on the serial monity
+
+  Hardware Connection:
+   Trig < -- > Arduino D3
+   Echo pin < -- > Arduino D4
+   VCC < -- > Arduino 5v
+   GND < -- > Arduino GND
+
+  by Dragino <support@dragino.com>
+  Dragino Technology Co., Limited
+*/
+
+// Set up SR04 pins to Arduino
+const int TrigPin = 3; 
+const int EchoPin = 4; 
+float distance; 
+void setup() 
+{   // initial serial connection
+        Serial.begin(9600); 
+        pinMode(TrigPin, OUTPUT); 
+    // Set up pin to input mode to detect wave width. 
+        pinMode(EchoPin, INPUT); 
+        Serial.println("Ultrasonic sensor:");
+} 
+void loop() 
+{ 
+    // Generate a 19us high wave to trigger TrigPin
+        digitalWrite(TrigPin, LOW); 
+        delayMicroseconds(2); 
+        digitalWrite(TrigPin, HIGH); 
+        delayMicroseconds(10);
+        digitalWrite(TrigPin, LOW); 
+    // Detect the Wave Length and Caculate the distance. 
+        distance = pulseIn(EchoPin, HIGH) / 58.00;
+        Serial.print(distance); 
+        Serial.print("cm"); 
+        Serial.println(); 
+        delay(1000); 
+}

libraries/Dragino/examples/LoRa/Concurrent/concurrent_client/concurrent_client.ino

@@ -32,7 +32,7 @@
 
 #include <SPI.h>
 #include <RH_RF95.h>
-#include <String.h>
+//#include <String.h>
 #include <EEPROM.h>
 #include "encrypt.h"
 

libraries/Dragino/examples/LoRa/LoRa_Mini_Low_Power/LoRa_Mini_Low_Power.ino

@@ -0,0 +1,108 @@
+/*
+  LoRa Mini Low Power :
+  Support Devices: LoRa Mini 
+  
+  Example to show how to put LoRa Mini in Low Power Mode
+
+  modified 19 Apr 2017
+  by Dragino <support@dragino.com>
+  Dragino Technology Co., Limited
+*/
+
+#include <SPI.h>
+#include <RH_RF95.h>
+#include <avr/sleep.h>
+#include <avr/wdt.h>
+
+RH_RF95 rf95;
+
+volatile byte wdt_counter=0;//Counter for Watch Dog
+
+void setup() 
+{
+  Serial.begin(9600);
+  if (!rf95.init())
+    Serial.println("init failed");
+
+
+// The modem config should be configured in RH_RF95.cpp : setModemConfig 
+//  rf95.setModemConfig(Bw125Cr45Sf128); 
+//  in this mode: transmit time: 52ms    Current: 126ma@3.3v   LoRa power: 23dBm  
+//  Ideal Case: Send a packet each 24 seconds, 2 x AA Battery can last about 2 year. (attention:the time need to double check)
+
+// The modem config should be configured in RH_RF95.cpp : setModemConfig 
+//  rf95.setModemConfig(Bw500Cr45Sf128); 
+//  in this mode: transmit time: 13ms    Current: 63ma@3.3v   LoRa power: 23dBm  
+//  Ideal Case: Send a packet each 24 seconds, 2 x AA Battery can last about 4 years. (attention:the time need to double check) 
+
+  rf95.setFrequency(915.0);
+  rf95.setTxPower(23);
+  setup_watchdog(9);//Set up WatchDog interupt time
+// 0=16ms, 1=32ms,2=64ms,3=128ms,4=250ms,5=500ms
+// 6=1 sec,7=2 sec, 8=4 sec, 9= 8sec
+
+  // Entering Sleeping Mode
+  ACSR |=_BV(ACD);//OFF ACD
+  ADCSRA=0;//OFF ADC
+  rf95.sleep();
+  Sleep_avr();//Sleep_Mode 
+}
+
+void loop()
+{
+  if (wdt_counter >= 3)// 3 interrupt counters then TX,total 24 Seconds 
+  {
+    Serial.println("Sending to rf95_server");
+    uint8_t data[] = "Hello World!";
+    rf95.send(data, sizeof(data));
+
+    rf95.waitPacketSent();
+    wdt_counter = 0; // Reset Counter
+
+    // Entering Sleeping Mode
+    ACSR |=_BV(ACD);//OFF ACD
+    ADCSRA=0;//OFF ADC
+    rf95.sleep();
+    Sleep_avr();//Sleep_Mode
+  }
+  else
+  {
+    // Entering Sleeping Mode
+    ACSR |=_BV(ACD);//OFF ACD
+    ADCSRA=0;//OFF ADC
+    rf95.sleep();
+    Sleep_avr(); 
+  }
+}
+
+//Set up sleep mode time. 
+void setup_watchdog(int time) {
+
+  byte wdt_time;
+
+  if (time > 9 ) time = 9;
+  wdt_time=time & 7;
+  if (time > 7) wdt_time |= ( 1 << 5 );
+  wdt_time |= ( 1 << WDCE );
+
+  MCUSR &= ~( 1 << WDRF );//Clear WDRF in MCUSR
+
+  // 启动时序
+  WDTCSR |= ( 1 << WDCE) | ( 1 << WDE );
+
+  // set up new watchdog timeout
+  WDTCSR = wdt_time;
+  WDTCSR |= _BV(WDIE);// close watchdog
+}
+
+//WDT interrupt
+ISR(WDT_vect) {
+  ++wdt_counter;
+}
+
+void Sleep_avr(){
+  set_sleep_mode(SLEEP_MODE_PWR_DOWN  ); // set up sleep mode
+  sleep_enable();  
+  sleep_mode();                        // entering sleep mode
+  rf95.sleep();
+}