Add documentation

README.md

@@ -1,2 +1,81 @@
 # arduino-eiscp
 Arduino library for controlling eISCP-based devices (eg. Onkyo and Pioneer receivers)
+## Installation 
+* Download the latest release from [here](https://github.com/krygacz/arduino-eiscp/releases)
+* Open Arduino IDE, click ```Sketch``` -> ```Include Library``` -> ```Add .ZIP Library``` and select the downloaded ZIP file
+## Usage
+Include the library in your code:
+```c++
+#include <eISCP.h>
+```
+### Initialization
+First, we need to create an eISCP instance. 
+In this example we'll be connecting to a device with IP ```192.168.100.8```
+and port ```60128```.
+
+We can initialize eISCP with ```WiFiClient```:
+```c++
+WiFiClient client_wifi;
+eISCP device("192.168.100.8", 60128, &client_wifi);
+```
+or ```EthernetClient```:
+```c++
+EthernetClient cllient_eth;
+eISCP device("192.168.100.8", 60128, &client_eth);
+```
+
+### Sending commands
+To send commands use the ```send(String command)``` function:
+```c++
+device.send("PWR01");
+```
+Response codes:
+* ```eISCP_SUCCESS``` - command sent successfully
+* ```eISCP_ERR_CONNECTION_FAILED``` - eISCP request failed
+* ```eISCP_ERR_CONNECTION_TIMEOUT``` - eISCP request timeout
+
+
+## Example
+```c++
+#include <ESP8266WiFi.h>
+#include <eISCP.h>
+
+const char* ssid      = "your-ssid";
+const char* password  = "your-password";
+const char* device_ip = "your-eISCP-device-ip";
+int device_port       = 60128;    // 60128 for Onkyo A/V receivers
+
+WiFiClient client;
+eISCP device(device_ip, device_port, &client);
+
+void setup() {
+  // Connect to a WiFi network
+  Serial.begin(115200);
+  Serial.print("\n\nConnecting to ");
+  Serial.println(ssid);
+  WiFi.mode(WIFI_STA);
+  WiFi.begin(ssid, password);
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    Serial.print(".");
+  }
+  Serial.println("\nConnected!");
+}
+
+void loop() {
+  // Command to be sent - eg. 'MVLUP' increments the volume on ONKYO receivers
+  // For more commands check out https://github.com/miracle2k/onkyo-eiscp/blob/master/eiscp-commands.yaml
+  String command = "MVLUP"; 
+
+  if(device.send(command) == eISCP_SUCCESS){
+    // Command was sent successfully
+    Serial.println("Command sent!");
+  } else {
+    // There was an error
+    Serial.println("Error!");
+  }
+
+  // Wait 60s
+  delay(60000);
+}
+```