Interfacing DC geared motor with Tiva C LaunchPad

In the previous chapter, we selected a DC geared motor with an encoder from Pololu and the embedded board from Texas Instruments called Tiva C LaunchPad. We need the following components to interface the motor with Launchpad:

• Two Pololu metal gear motors 37Dx57L mm with 64 count per revolution encoder
• Pololu wheel 90x10 mm and a matching hub
• Pololu dual VNH2SP30 motor driver carrier MD03A
• A sealed lead acid/Lithium Ion battery of 12 V
• A logic level convertor of 3.3 V to 5 V https://www.sparkfun.com/products/11978.
• A Tiva C LaunchPad and its compatible interfacing wires

The following figure shows the interfacing circuit of two motors using Pololu H-Bridge:

Motor interfacing circuit

To interface with Launchpad, we have to connect a level shifter board in between these two. The motor driver works in 5 V but the Launchpad works in 3.3 V, so we have to connect a level shifter, as shown in the following figure:

Level shifter circuit

The two geared DC motors...