Restored after screw up by @off14

Sonoff-RF.md

@@ -1,6 +1,15 @@
-Answers needed:
+## Pairing a RF remote control
+During programming a connection for R21 is needed in order to use a button press to ground GPIO0.
 
-1. How to pair remote
-2. How to see paired remotes (if possible)
-3. how rf module interacts? is it using gpio14 or what?
-4. Can i use GPIO14 in sonoff rf? if yes, are all the options ok?
+To pair a RF remote control with the Sonoff RF it is important that there is NO connection made for R21.
+
+User [gadjet](https://github.com/gadjet) installed a jumper in place of R21 allowing easy programming (jumper in), pairing (jumper out) and normal use (jumper out).
+
+<img alt="RF jumper" src="https://github.com/arendst/arendst.github.io/blob/master/media/sonoffrfjmpr.jpg" align="left" /> 
+
+### Procedure
+Pairing the iTead RF remote controller is the same as with the original iTead software:
+- two short button presses will blink a red led shortly and start RF signal recognition. Three longer blinks signal RF reception.
+- three short button presses will keep the red led on for some seconds and erase the known RF code. 
+
+I was unable to pair the Sonoff RF 434MHz receiver with my KaKu switches but the iTead provided remote control works just fine.