4 - Connecting the microcontroller


I’ve chosen to use my Baby Orangutan board because it can plug straight into the breadboard. This board uses an AVR ATMega168. If you want to use your $50 Robot Board then that is fine as well:- just make sure that your $50 Robot ground and +5v are also connected to the breadboard to drive pin 16 of the L293D. You can do this by connecting a lead from one of your unused analogue-to-digital ports and connecting the ground wire to the ground of your breadboard, and the +5v to pin 16 of your L293D. Obviously the 3rd pin of the connector (which would normally be used for the sensor input voltage) will be left un-connected.


Now we need to choose 4 output pins from the micro-controller that we will use to run the L293D.  I selected:-

Port C5 = 1a

Port C4 = 1b

Port C3 = 2a

Port C2 = 2b