add first OTA description

doc/ota_updates.md

@@ -0,0 +1,68 @@
+---
+title: OTA Update
+---
+
+## Table of Contents
+ * [Requirements](#Requirements)
+ * [Arduino IDE](#arduino-ide)
+ * [HTTP Server](#http-server)
+ * [Stream Interface](#stream-interface)
+ 
+## Requirements
+
+Basic requirement:
+- Flash chip size is 2x the size of the sketch
+ 
+## Arduino IDE
+
+TODO describe Arduino IDE OTA process
+
+### Requirements
+ - The ESP and the Computer must be connected to the Same network.
+
+
+## HTTP Server
+
+the ```ESPhttpUpdate``` class can check for updates and download a binary file form a HTTP web server.
+It is possible to download updates from every IP or domain address on the Network or Internet.
+
+
+### Requirements
+ - web server
+
+
+### Arduino code
+
+simple updater:
+```cpp
+ESPhttpUpdate.update("192.168.0.2", 80, "/arduino.bin");
+```
+
+advanced:
+```cpp
+t_httpUpdate_return ret = ESPhttpUpdate.update("192.168.0.2", 80, "/esp/update/arduino.php", "optional current version string here");
+switch(ret) {
+	case HTTP_UPDATE_FAILD:
+		Serial.println("[update] Update fail.");
+		break;
+	case HTTP_UPDATE_NO_UPDATES:
+		Serial.println("[update] Update no Update.");
+		break;
+	case HTTP_UPDATE_OK:
+		Serial.println("[update] Update ok."); // may not called we reboot the ESP 
+		break;
+}
+```
+
+### Server request handling
+
+TODO server side 
+
+## Stream Interface
+
+TODO describe Stream Interface update proccess
+
+```cpp
+	ESP.updateSketch(client, length);
+```
+