update: update readme

README.md

@@ -1,13 +1,65 @@
 # Seeed_Arduino_LIS3DHTR  [![Build Status](https://travis-ci.com/Seeed-Studio/Seeed_Arduino_LIS3DHTR.svg?branch=master)](https://travis-ci.com/Seeed-Studio/Seeed_Arduino_LIS3DHTR)
 ## Introduction 
 An Arduino library for 3-Axis Digital Accelerometer ±2g to 16g (LIS3DHTR).Acceleration data can be obtained using IIC interface and SPI interface.
+## How to install  Arduino Library
+please refer [here](https://wiki.seeedstudio.com/How_to_install_Arduino_Library/).
+
 ## Usage
-    1.Git clone this resp to your Arduino IDE's libraries directory.
-    2.Run the demo "LIS3DHTR_IIC" or "LIS3DHTR_SPI" on examples directory.
 
-----
+```C++
+// This example use I2C.
+#include "LIS3DHTR.h"
+#include <Wire.h>
+LIS3DHTR<TwoWire> LIS; //IIC
+#define WIRE Wire
+
+void setup()
+{
+  Serial.begin(115200);
+  while (!Serial)
+  {
+  };
+  LIS.begin(WIRE, LIS3DHTR_ADDRESS_UPDATED); //IIC init
+  delay(100);
+  LIS.setOutputDataRate(LIS3DHTR_DATARATE_50HZ);
+
+}
+void loop()
+{
+  if (!LIS)
+  {
+    Serial.println("LIS3DHTR didn't connect.");
+    while (1)
+      ;
+    return;
+  }
+  //3 axis
+   Serial.print("x:"); Serial.print(LIS.getAccelerationX()); Serial.print("  ");
+   Serial.print("y:"); Serial.print(LIS.getAccelerationY()); Serial.print("  ");
+   Serial.print("z:"); Serial.println(LIS.getAccelerationZ());
+
+}
+
+```
 
-This software is written for seeed studio and is licensed under [The MIT License](http://opensource.org/licenses/mit-license.php). Check License.txt for more information.<br>
+## API Reference
+
+- **begin(*comm\<TwoWire\>, address\<uint8_t\>=0x18*)** :  Init device
+```C++
+LIS3DHTR<TwoWire> LIS; //IIC
+LIS.begin(Wire, 0x19)
+```
+
+- **begin(*comm\<SPIClass\>, sspin\<uint8_t\>=SS*)** :  Init device
+```C++
+LIS3DHTR<SPIClass> LIS; //SPI
+LIS.begin(SPI, 10); //SPI SS/CS
+```
+
+----
+## License
+This software is written by seeed studio<br>
+and is licensed under [The MIT License](http://opensource.org/licenses/mit-license.php). Check License.txt for more information.<br>
 
 Contributing to this software is warmly welcomed. You can do this basically by<br>
 [forking](https://help.github.com/articles/fork-a-repo), committing modifications and then [pulling requests](https://help.github.com/articles/using-pull-requests) (follow the links above<br>
@@ -17,7 +69,4 @@ Thanks for your contribution.
 Seeed Studio is an open hardware facilitation company based in Shenzhen, China. <br>
 Benefiting from local manufacture power and convenient global logistic system, <br>
 we integrate resources to serve new era of innovation. Seeed also works with <br>
-global distributors and partners to push open hardware movement.<br>
-
-
-[![Analytics](https://ga-beacon.appspot.com/UA-46589105-3/grove-human-presence-sensor)](https://github.com/igrigorik/ga-beacon)
+global distributors and partners to push open hardware movement.<br>