These are all that are needed to control the motors individually. Combined with setspeed these can expand your usage!
So you could use something like below. I haven't used my arduino in a while so there will be paraphrasing and such but this is just the idea of usage I will try to get the commands correct.
this code will use a function to move the"car"forward at half speed for 5 seconds then stop for 5 seconds looping continuously.
You can of course add in your own sensors or variables to call the different functions at different times to make a car the reacts to it's environment (sonar) or follows a line (infrared), or both!
int forwardspeed = 125;
delay(5000); //or a variable if you wish
setSpeed(125, MOTORA); //alternatively replace the 125 in this line with forwardspeed so you can control speed on the fly
I hope the reveal of these pieces of code (while not ground breaking) make the motor shield more accessible to all users so we can see what gets made. :)
Said video of this code working though i added a couple more functions so i could turn the front wheels, and also spun the rears in both directions.