"PLL Mode"

Pin

Function

Digital 4

Motor 1 Enable control

Digital 5

Motor 1 Direction control

Digital 6

Motor 2 Direction control

Digital 7

Motor 2 Enable control

PWM Control Mode

Fig4: PWM Motor Control Pin Allocation

The PWM DC motor control is implemented by manipulating two digital IO pins and two

PWM pins. As illustrated in the diagram above (Figure 5), Pin 4,7 (7,8 for old Romeo

version) are motor direction control pins, Pin 5,6 (6,9 for old Romeo version) are motor

speed control pins.

Sample Code：

//Standard PWM DC control

int E1 = 5;

//M1 Speed Control

int E2 = 6;

//M2 Speed Control

int M1 = 4;

//M1 Direction Control

int M2 = 7;

//M1 Direction Control

///For previous Romeo, please use these pins.