Fix reset for leonardo

I found that the previous reset code did not work for Leonardo or Micro, nor did any reset code anywhere on the internet.

An examination of the Arduino IDE source code (and the JNI code behind its serial implementation) shows that it holds RTS high and DTR low when doing the 1200 baud open/close. And it turns out that's exactly what's needed!

HISTORY.md

@@ -53,6 +53,7 @@ I tried to give credit whenever possible. If I have missed anyone, kindly add it
 - Fix: Can now find IDE 1.5+ preferences.txt on Linux and Mac (https://github.com/sej7278)
 - Fix: Added support for VARIANT being a submenu item in 1.6 cores like attiny (https://github.com/sej7278)
 - Fix: Replaced copyright symbol causing sed problems on OSX (Issue #335). (https://github.com/sej7278)
+- Fix: Fix issues with resetting Leonardo and Micro boards(Issue #340) (https://github.com/calvinli)
 
 ### 1.3.4 (2014-07-12)
 - Tweak: Allow spaces in "Serial.begin (....)". (Issue #190) (https://github.com/pdav)

bin/ard-reset-arduino

@@ -17,10 +17,10 @@ if args.caterina:
     if args.verbose: print('Forcing reset using 1200bps open/close on port %s' % args.port[0])
     ser = serial.Serial(args.port[0], 57600)
     ser.close()
-    ser.open()
-    ser.close()
     ser.setBaudrate(1200)
     ser.open()
+    ser.setRTS(True)  # RTS line needs to be held high and DTR low
+    ser.setDTR(False) # (see Arduino IDE source code)
     ser.close()
     sleep(1)