PossiblyHeroin:
Fantastic, thank you very much OldSteve
No problem.
And, just to confirm, presumably the motor will only draw as much current as it needs - and so if it's a 300mA motor and the power supply is 1A, then nothing should blow up?
Thanks again.
That actually depends on how heavily the motor is loaded. Startup current will be several times running current, but a capacitor across the motor supply will alleviate that. Under heavy load, though, the motor could easily draw 1A. If you're not loading it too heavily, you shouldn't have problems. Just keep an eye on the temperature of the chip. The L293NE can handle 1A continuous, or 2A peak, but they're notorious for getting hot, due to the saturation voltage of the output transistors.
Normally the ground pins can be connected to a large area of copper on a PCB, to act as a heatsink, but that's not possible on a breadboard.