Usage

Hardware configuration

The library is designed to be used in different hardware configurations:

standalone configuration

This configuration in intended for use with a standalone L293 IC and breakout boards that expose the ENABLE pin and the two INPUTS, using 3 wires for each motor to control ( excluding the power supply ). The circuit must be like this:

twoWire configuration

This configuration is intended for use with a circuit like this:

Where only two wires are used to control the motor: the PWM signal and the direction signal ( excluding the power supply )

Software

The library offers differentiated functions for different hardware configurations, but there are some common structures and behaviors

Common reference

• Moving the motor

Method	Description
motor.forward( speed );	makes the motor to go forward, **speed** can be a value beetween 0 and 255
motor.forward();	makes the motor to go forward without modifing the speed
motor.back( speed );	makes the motor to go reverse, **speed** can be a value beetween 0 and 255
motor.back();	makes the motor to go reverse without modifing the speed
motor.stop();	stops the motor
motor.setPWMOffset( speedOffset );	sets the offset value applied to the pwm signal value, **speedOffset** can be a value beetween -255 and 255
motor.getRawPWMDC();	returns the current speed value whitout appling the speed offset
motor.getPWMDC();	returns the real current speed value
motor.isForward();	returns **true** if the motor is turning forward
motor.isReverse();	returns **true** if the motor is turning reverse
motor.isStopped();	returns **true** if the motor is stopped

Reference for the standalone configuration only

• Creating an istance

L293 motor(pwmPin, forwardPin, backPin);
L293 motor(pwmPin, forwardPin, backPin, speedOffset);

Parameter	Description
motor	the name of the object
pwmPin	the pin that generate the pwm signal used to control the motor speed
forwardPin	the digital pin used to tell the motor to go forward
backpin	the digital pin used to tell the motor to go reverse
speedOffset	the offset value applied to the pwm signal value, used to reduce the power given to a motor (can be a value beetween -255 and 255) (e.g. in a robot two motors must rotate at the same speed, but one is more powerful than other)

• Moving the motor

Method	Description
motor.forceStop( handlingTime );	stops the motor electrically braking it, handlingTime is the time in milliseconds during which the motor is braked, the recommended value is 100
motor.isForceStopped();	returns **true** if the motor is electrically braked

Reference for the L293_twoWire configuration only

• Creating an istance

		L293_twoWire motor(pwmPin, directionPin);
		L293_twoWire motor(pwmPin, directionPin, speedOffset);

Method	Description
motor	the name of the object
pwmPin	the pin that generate the pwm signal used to control the motor speed
directionPin	the digital pin used to manage the motor direction
speedOffset	the offset value applied to the pwm signal value, used to reduce the power given to a motor (can be a value beetween -255 and 255) (e.g. in a robot two motors must rotate at the same speed, but one is more powerful than other)