Hi Tam,
Welcome to the forums.
Unfortunately, it's never a good sign if you see the magic smoke escaping from your electronics, so I'm afraid, that yes, you probably will need a new Mini Driver in order to get your robot fully working.
Having said that, you may have only fried part of your board so you might still be able to use the Mini Driver as an Arduino, or to drive one motor.
The best way to test is to try to program the Mini Driver from a PC, by connecting it up using the supplied USB cable (if you're using Windows then you'll need to install some drivers which are linked to on the Mini Driver
product page). We have a
blog post which explains how to program the Mini Driver. If you're able to get the test program to upload then that's a good sign (as you have a programmable microcontroller you can use to control electronics) and if the program then makes motors move (you'll need batteries attached for that) then that's even better.
Best of luck testing your Mini Driver.
Regards
Alan