Update README.md

README.md

@@ -25,4 +25,28 @@ RF24_config.h
 
 Only ATXMega256D3 is supported right now!
 
+## Notes
+The millisecond functionality is based on the TCE0 so don't use these pins as IO.
+
+
+## Usage
+Add the library to your project!
+In the file where the **main()** is put the following in order to update the millisecond functionality:
+```
+ISR(TCE0_OVF_vect)
+{
+	update_milisec();
+}
+```
+
+Declare the rf24 radio with **RF24 radio(XMEGA_PORTC_PIN3, XMEGA_SPI_PORT_C);**
+
+First parameter is the CE pin which can be any available pin on the uC.
+
+Second parameter is the CS which can be on port C (**XMEGA_SPI_PORT_C**) or on port D (**XMEGA_SPI_PORT_D**). 
+
+Call the **__start_timer()** to start the millisecond timer.
+
+
+
 ** For further information please see http://tmrh20.github.io/RF24 for all documentation**