It depends on the microcontroller. Some just have a single output which is the SIGNAL wire. Others have a 5v+ and ground wire also. (what microcontroller r u using, can u post a diagram of it).
Basically u need to use the signal wire to switch on another circuit. u can hook a transistor up to a circuit with (say) your motors and a battery. and connect the signal wire to the transistor.
So basically the transistor is like a switch in your circuit (in which u can hook up a motor or a led or whatever) and the transistor is simply turned on when a signal comes out of ur microcontroller and into the transistor.
Alternatively u can use a MOSFET or a relay to do the same thing.
But remember when u send a digital "1" out of ur microcontroller u are sending 5V which u need to run into a switching component like a MOSFET or transistor to switch on another circuit.
