Update README.md

README.md

@@ -2,7 +2,8 @@
 flash CC2531 USB dongle from your Raspberry, without Arduino nor CC Debugger.
 
 ## prerequisites
-A Raspberry Pi 3 with raspbian and [wiringPi](http://wiringpi.com/) installed.
+You need a Raspberry with [wiringPi](http://wiringpi.com/) installed.  
+I have designed flash_cc2531 on a Raspberry Pi 3 with raspbian, but successful flashes have been reported on pi 1 and pi 2 : see sections [use other pins](#use-other-pins) and [what to try if it doesn't work](#what-to-try-if-it-doesnt-work).
 
 ## Getting Started
 
@@ -52,7 +53,7 @@ To flash file to cc2531 :
 ```
 (takes around 3 minutes).
 
-## Using other pins
+## Use other pins
 all commands accept following arguments :
 ```bash
         -c pin : change pin_DC (default 27)