Arduino Motor Shield

Question

It seems that I can't get the DC Motor function to work while also having servos driven off the other ports :(

#include "Arduino.h"
#include <Servo.h>
int pinI1=8;//define I1 interface
int pinI2=11;//define I2 interface 
int speedpinA=9;//enable motor A
int pinI3=12;//define I3 interface 
int pinI4=13;//define I4 interface 
int speedpinB=10;//enable motor 
int spead =220;//define the spead of motor
Servo SteeringServo; // create servo object to control a servo 
void setup()
{
 // Steering servo pin setup
 SteeringServo.attach(5); // attaches the servo on pin 9 to the servo object
 pinMode(pinI1,OUTPUT);
 pinMode(pinI2,OUTPUT);
 pinMode(speedpinA,OUTPUT);
 pinMode(pinI3,OUTPUT);
 pinMode(pinI4,OUTPUT);
 pinMode(speedpinB,OUTPUT);
 Serial.begin(9600);
}
void forward()
{
 analogWrite(speedpinA,spead);//input a simulation value to set the speed
 analogWrite(speedpinB,spead);
 digitalWrite(pinI4,HIGH);//turn DC Motor B move clockwise
 digitalWrite(pinI3,LOW);
 digitalWrite(pinI2,LOW);//turn DC Motor A move anticlockwise
 digitalWrite(pinI1,HIGH);
}
void backward()//
{
 analogWrite(speedpinA,spead);//input a simulation value to set the speed
 analogWrite(speedpinB,spead);
 digitalWrite(pinI4,LOW);//turn DC Motor B move anticlockwise
 digitalWrite(pinI3,HIGH);
 digitalWrite(pinI2,HIGH);//turn DC Motor A move clockwise
 digitalWrite(pinI1,LOW);
}
void left()//
{
 analogWrite(speedpinA,spead);//input a simulation value to set the speed
 analogWrite(speedpinB,spead);
 digitalWrite(pinI4,HIGH);//turn DC Motor B move clockwise
 digitalWrite(pinI3,LOW);
 digitalWrite(pinI2,HIGH);//turn DC Motor A move clockwise
 digitalWrite(pinI1,LOW);
}
void right()//
{
 analogWrite(speedpinA,spead);//input a simulation value to set the speed
 analogWrite(speedpinB,spead);
 digitalWrite(pinI4,LOW);//turn DC Motor B move anticlockwise
 digitalWrite(pinI3,HIGH);
 digitalWrite(pinI2,LOW);//turn DC Motor A move clockwise
 digitalWrite(pinI1,HIGH);
}
void stop()//
{
 digitalWrite(speedpinA,LOW);// Unenble the pin, to stop the motor. this should be done to avid damaging the motor. 
 digitalWrite(speedpinB,LOW);
 delay(1000);
}
void loop()
{
 left();
 delay(15000); 
 stop();
 right();
 delay(1000);
 stop();
 // delay(2000); Already commented out
 //forward();
 // delay(2000);
 // stop();
// backward();
 delay(12000); 
 stop(); 
}

Answer 1

Your code:

int speedpinA=9;//enable motor A
...
int speedpinB=10;//enable motor 
...
 analogWrite(speedpinA,spead);//input a simulation value to set the speed
 analogWrite(speedpinB,spead);

See https://www.arduino.cc/en/reference/servo

On boards other than the Mega, use of the library disables analogWrite() (PWM) functionality on pins 9 and 10, whether or not there is a Servo on those pins.

(My emphasis).

So, you can't do that, exactly. Perhaps choose other pins for the analogWrite, pins that analogWrite supports, that are not 9 and 10.