MakeyMakey + Arduino I am trying to use the MakeyMakey with the Arduino (not as an Arduino) and then use a USB to TTL module to send the keys pressed to the Arduino. Is this possible? Do I have to reprogram?
one possibility is to use HOST SHIELD 
http://www.circuitsathome.com/products-page/arduino-shields

Arduino is now as host
Makey is keyboard