How to use two motors simultaneously with an Arduino uno

Question

Hi,

I am having trouble making two DC motors work simultaneously working with the Arduino Uno. One motor on its own works fine but both of them do not work together. It would be nice if someone could help me with the circuit and the code.

Thanks in Advance,

Ramgopal

vish · Answer

Hi Ram, If I want to control two motors, I will go for a driver circuit. One best solution is to use a motor driver IC. L293D is one of the inexpensive yet excellent ICs for this purpose. You will be able to pick up one form your nearest electronics shop for around Rs 60( if u r in India). I have used them in my robotics projects. Also this IC has protection circuits for back emf, so no worries about frying your arduino. If you can dedicate two GPIO pins per motor, you will be able to control the motor in both directions. If you can afford only one GPIO, then you can ground the other input pin in L293D and control the motor with just start/stop functionality. You can find a good tutorial about interfacing arduino with motors using L293D here ; Control a DC motor with Arduino and L293D chip Control your motors with L293D and Arduino -vish

Robert Peter Oakes · Answer

Based on the diagram, you may be overloading the 5v rail of the arduino, it is not designed to supply the load to two motors. Try powering the motors from a desperate supply, only share a common ground between the motors and the arduino, alternately relaxed the two motors with LEDs and a 500r resistor between the led and 5v if this configuration works then it is you load from the motors Sent from my iPhone

dragonstyne · Answer

Peter's answer is the correct solution. Ravi's answer is correct if, you apply Peter's logic. You need a separate power supply to provide enough current to drive the motors without destroying the Arduino. -Steve

nschreiber0813 · Answer

Dear: Ramgopal

I have used two dc motors with arduino uno before and I noticed a simular problem. See the problem is the board is over heating because two servos use a lot of power. So my suggestion for you is to either use a different brand of servos or use a different PCB. See if you have a heating solution you should be less likely to run into this problem. If you continue you could break your UNO board and your servos so be careful.

From: Noah

ussengineers · Answer

Yep I agree, although arduino's are great they struggle for supply power hungry circuitry such as motors. It is very easy to solve this by using a driver circuit, which can be as simple as a transistor, connect the base to the arduino for control, connect the collector to an external power supply, such as a 9V battery and connect the emitter to ground via a resistor, should supply enough current to keep everything moving!

ravi_butani · Answer

You will need separate drive circuit (transistor and resistor) for both motor... u can use same code with two pin..

jomoenginer · Answer

This is an old thread, however if you are just looking to control 2 DC motors, then you could just add a second definition for the second motor and then just turn both on for forward motion, or turn each off for left and right action. the best bet is to add a driver transistor for each motor and use it as a switch which will allow you to not over draw the current from the Arduino GPIO pins.

Something like the follow would work nicely and all you would have to do is duplicate the circuit and GPIO pin definition for the second motor:

https://www.arduino.cc/en/Tutorial/TransistorMotorControl

However, if you are looking for some forward and backward action with the motor, then you would have to build an H-bridge or by a Motor Shield which will give you more control of the motor movement.

The Adafruit TB6612 Breakout board is an inexpensive H-Bridge that can control 2 DC Motors.

https://www.adafruit.com/product/2448?gclid=Cj0KCQjw2KHWBRC2ARIsAJD_r3fSQvAKYUfufOVrEnXzuht1tRHnaku1np6bdeKDh9G_pJFtiXtVgtcaAuNKEALw_wcB

Or you can DIY it with a L293D Quad Half-H Bridge

http://www.ti.com/product/L293D

This might help answer some questions, or raise new ones:

https://www.element14.com/community/docs/DOC-89005#comment-127024

How to use two motors simultaneously with an Arduino uno

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