The server will send the required values for both motors. For each motor, we need a speed variable (a PWM value between 0 and 255) and a direction variable (0 or 1). We will send the values from the server to the robot by inserting a comma between each variable:
speed_motor1,speed_motor2,direction_motor1,direction_motor2,
Theses variables are stored in an array of integers that we have to declare: