I'm trying to decide weither i can use a Arduino Uno for my project or i need a Arduino Mega.
i need to power 4x http://www.seeedstudio.com/wiki/13.56Mhz_RFID_module_-_IOS/IEC_14443_type_a and read and write data over its TTL interface.
Now i do know that the Arduino Mega has 4 Rx and Tx ports but i am not sure if these are needed since in http://www.seeedstudio.com/wiki/File:Rdm880_bb.png they are connecting the Rx and Tx of the module to I/O pin 2 and 3 of the Arduino. (this could mean an Uno could connect 4 modules too? )
Anyone could tell me if i could power them with either one(maybe even an other Arduino?) and which one would be the best choice?
Also Serial ( 0 ,1 ) does communicate via USB right? So connecting a module to this port will make all data sent go to PC too?
Thanks in advance