One of the easiest and inexpensive way to control stepper motors is to interface L293D Motor Driver IC with Arduino. It can control both speed. Controlling a DC MotorIn order to have a complete control over DC motor, we have to control its speed and rotation direction. This can be achieved by combining these two techniques. PWM – For controlling speed. H-Bridge – For controlling rotation directionPWM – For controlling speedThe speed of a DC motor can be controlled by varying its input voltage. A common technique for doing this is to use PWM (Pulse Width Modulation)PWM is a technique where average value of the input voltage is adjusted by sending a series of ON-OFF pulses.The average voltage is proportional to the width of the pulses known as Duty Cycle.The higher the duty cycle, the greater the average voltage being applied to the dc motor(High Speed) and the lower the duty cycle, the less the average voltage being applied to the dc motor(Low Speed).Below image illustrates PWM technique with various duty cycles and average voltages.
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Pulse Width Modulation(PWM) Technique H-Bridge – For controlling rotation directionThe DC motor’s spinning direction can be controlled by changing polarity of its input voltage. A common technique for doing this is to use an H-Bridge.An H-Bridge circuit contains four switches with the motor at the center forming an H-like arrangement.Closing two particular switches at the same time reverses the polarity of the voltage applied to the motor. This causes change in spinning direction of the motor.Below animation illustrates H-Bridge circuit working. The L293D motor driver’s output channels for the motor A and B are brought out to pins OUT1,OUT2 and OUT3,OUT4 respectively.You can connect two DC motors having voltages between 4.5 to 36V to these terminals.Each channel on the IC can deliver up to 600mA to the DC motor. However, the amount of current supplied to the motor depends on system’s power supply. Control PinsFor each of the L293D’s channels, there are two types of control pins which allow us to control speed and spinning direction of the DC motors at the same time viz. Direction control pins & Speed control pins.
The project designed around L293D IC. The L293D device is quadruple. L293D Adapter Board can be used as dual DC motor driver or bipolar stepper motor driver. Useful in robotics. The pins of L293D motor driver IC are connected to connectors for easy access to the driver IC’s pin functions. The L293D is a Dual Full Bridge driver that can drive up to 1Amp per bridge with supply voltage up to 24V. It can drive two DC motors, relays, solenoids, etc. The device is TTL compatible. Two H bridges of L293D can be connected in parallel to.
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Direction Control Pins. The speed control pins viz. ENA and ENB are used to turn ON, OFF and control speed of motor A and motor B respectively.Pulling these pins HIGH will make the motors spin, pulling it LOW will make them stop.
But, with Pulse Width Modulation (PWM), we can actually control the speed of the motors. Wiring L293D motor driver IC with Arduino UNONow that we know everything about the IC, we can begin hooking it up to our Arduino!Start by connecting power supply to the motors. In our experiment we are using DC Gearbox Motors(also known as ‘TT’ motors) that are usually found in two-wheel-drive robots. They are rated for 3 to 9V. So, we will connect external 9V power supply to the Vcc2 pin.Next, we need to supply 5 Volts for the L293D’s logic circuitry. Connect Vcc1 pin to 5V output on Arduino.
Make sure you common all the grounds in the circuit.Now, the input and enable pins(ENA, IN1, IN2, IN3, IN4 and ENB) of the L293D IC are connected to six Arduino digital output pins(9, 8, 7, 5, 4 and 3). Note that the Arduino output pins 9 and 3 are both PWM-enabled.Finally, connect one motor to across OUT1 & OUT2 and the other motor across OUT3 & OUT4. You can interchange your motor’s connections, technically, there is no right or wrong way.When you’re done you should have something that looks similar to the illustration shown below.
Hello everyone! I hope you all will be absolutely fine and having fun. Today I am going to given elaboration on Introduction to L293D. L 293D is basically a high current dual motor driver/controller Integrated Circuit (IC). It is able to drive load having current up to 1A at the voltage ranging from 4.5V to 36V. Motor driver usually act as current amplifier because they receive a low current signal as an input and provides high current signal at the output.Motors usually operates on this higher current. L-293D has to builtin H-Bridge driver circuits and is able to control two DC motors at a time in both clockwise and counter clockwise direction.
It has two enable pins and they should be kept high in order to control the motor. By changing the polarity of applied signal motor can be rotated in either clockwise or counter clockwise direction. If L 293D enable pin is high, its corresponding driver will provide the desired out. If the enable pin is low, there will be no output. L-293D has different features including internal ESD protection, large voltage supply range, large output current per channel, high noise immunity input etc.
L 293D plays a vital role in electronics era and has several different applications e.g relay drivers, DC motor drivers, stepping motor drivers etc. The further detail about L 293D motor driver/controller will be given later in this tutorial.
Introduction to L293DL293D is basically a motor driver or controller. It has two builtin H-bridge circuits which are able to control two DC motors simultaneously in both clockwise and counter clockwise direction. It acts as an current high amplifier because it take low current signal at its input and provides higher current signal at the output in order to drives different load e.g stepper motor & DC motors. Its features include large inpu voltage supply range, large output current high noise immunity input signals etc. Its common real life applications include stepping motor drivers, relay drivers, DC motor drivers etc. L-293D motor driver/controller is shown in the figure given below.1. L293D has a lot of applications including:.
DC motor drivers. Relay drivers. Stepper motor drivers. Two phase motor driver, block diagram of L 293D application for two phase motor is given in the figure shown below.In the tutorial Introduction to L293D, I have shared all the necessary details about L 293D motor controller/driver which includes its pinout diagram, applications, features, functional and logic diagram, packages etc. Let me know if I have missed something. If you have any issues you can find each kind of help regarding your issues. Our team is always available here to help you.
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In my upcoming articles I will share other informative IC’s as well. Till then take care ?.
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March 2023
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