New v3HP exmaple for PWM mode

Change-Id: If0316644cba19a9e717ba9d6471e80ba4f5654c2

examples/v3HP/v3HP_PWM/v3HP_PWM.ino

@@ -0,0 +1,103 @@
+/*------------------------------------------------------------------------------
+
+  LIDARLite Arduino Library
+  v3HP/v3HP_PWM
+
+  This example shows how to read distance from a LIDAR-Lite connected over the
+  PWM interface.
+
+  Connections:
+  LIDAR-Lite 5 Vdc (red) to Arduino 5v
+  LIDAR-Lite Ground (black) to Arduino GND
+  LIDAR-Lite Mode control (yellow) to Arduino digital input (pin 3)
+  LIDAR-Lite Mode control (yellow) to 1 kOhm resistor lead 1
+  1 kOhm resistor lead 2 to Arduino digital output (pin 2)
+
+  Optional Connections -
+      LIDAR-Lite I2C SCL (green) to Arduino SCL
+      LIDAR-Lite I2C SDA (blue) to Arduino SDA
+
+  (Capacitor recommended to mitigate inrush current when device is enabled)
+  680uF capacitor (+) to Arduino 5v
+  680uF capacitor (-) to Arduino GND
+
+  See the Operation Manual for wiring diagrams and more information:
+  http://static.garmin.com/pumac/LIDAR-Lite_v3HP_Instructions_EN.pdf
+------------------------------------------------------------------------------*/
+
+#include <stdint.h>
+#include <Wire.h>
+#include "LIDARLite_v3HP.h"
+
+LIDARLite_v3HP myLidarLite;
+
+#define MonitorPin    3
+#define TriggerPin    2
+
+uint32_t distance;
+uint32_t startTime;
+uint32_t endTime;
+bool     newDistance = false;
+bool     measuring   = false;
+
+// -----------------------------------------
+// Add in the #define below to illustrate
+// optional use of I2C during PWM mode
+// -----------------------------------------
+//#define USE_I2C
+
+void setup()
+{
+    Serial.begin(115200); // Start serial communications
+
+    #ifdef USE_I2C
+        // Initialize Arduino I2C (for communication to LidarLite)
+        Wire.begin();
+        Wire.setClock(400000UL); // Set I2C frequency to 400kHz (for Arduino Due)
+    #endif
+
+    pinMode(MonitorPin, INPUT);
+    pinMode(TriggerPin, OUTPUT);
+    digitalWrite(TriggerPin, LOW); // Set trigger LOW for continuous read
+
+    startTime = micros();
+    endTime   = startTime;
+}
+
+void loop()
+{
+    if (digitalRead(MonitorPin))
+    {
+        if (measuring == false)
+        {
+            startTime   = micros();
+            measuring   = true;
+        }
+    }
+    else
+    {
+        if (measuring == true)
+        {
+            endTime     = micros();
+            measuring   = false;
+            newDistance = true;
+        }
+    }
+
+    // If we get a new reading, print it
+    if (newDistance == true)
+    {
+        distance = (endTime - startTime) / 10; // 10usec = 1 cm of distance
+        Serial.println(distance); // Print measured distance
+
+        #ifdef USE_I2C
+            uint8_t  signalStrength = 0;
+            myLidarLite.read(0x0e, &signalStrength, 1);
+            Serial.print("SS = ");
+            Serial.println(signalStrength, DEC);
+            Serial.println();
+        #endif
+
+        newDistance = false;
+    }
+}