Connect the battery to the bridge as well as have an extra cable to connect the ground to the Raspberry Pi
Cut a a rectangle-shaped cardboard piece to use it as a frame and place the motors on it and make holes to pass the cables to the upper section.
Lastly connect the Raspberry pi with the bridge as shown, using the 4 "IN" pins to control the wheels and make sure you have an external power supply that gives enough voltage for the pi.
When finished using it, make sure you remove one of the baterries from the baterry pack to prevent drainage
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