DFRobot DFRduino Romeo-All in one Controller V1.1 Manual page 9

{
analogWrite (E1,a);
digitalWrite(M1,LOW);
analogWrite (E2,b);
digitalWrite(M2,LOW);
}
void turn_L (char a,char b)
{
analogWrite (E1,a);
digitalWrite(M1,LOW);
analogWrite (E2,b);
digitalWrite(M2,HIGH);
}
void turn_R (char a,char b)
{
analogWrite (E1,a);
digitalWrite(M1,HIGH);
analogWrite (E2,b);
digitalWrite(M2,LOW);
}
void setup(void)
{
int i;
for(i=4;i<=7;i++)
pinMode(i, OUTPUT);
Serial.begin(19200);
Serial.println("Run keyboard control");
}
void loop(void)
{
if(Serial.available()){
char val = Serial.read();
//Turn Left
//Turn Right
//Set Baud Rate