Turn the speakerphone on a call using ADB shell

I'm trying to find a command in adb shell that [lets me turn on the speakerphone when I start a call](http://developer.android.com/reference/android/view/KeyEvent.html) . First I make the call adb shell service call phone 1 s16 "" s16 "#####" the call starts and I try to start the speakerphone with something like this: adb shell input keyevent