Let's Make Robots! | RobotShop


Control DC motors with a Grove H-Bridge and DynamixShield

I just uploaded a new video tutorial on how to use the Grove dual H-Bridge module with the DynamixShield and an Arduino Due to control DC motors. 

Grove H-Bridge with DynamixShield

Differencial Drive using one PWM and 4 GPIO

I want to make a differencial drive using only one PWM and 4 GPIO pins, because the motors always move in the same speed irrespective of their direction. So I have designed this H-Bridge Motor Driver, I want to make sure it works, before trying it out practically.



Transistor based H-Bridge

Hello everyone I realised after burning through 6 L293D's that they were getting old. I hated them mostly due to the fact that they were fragile. I also burned 3 of them because of static electricity. So I decided to try and make a cheap H-Bridge from transistors. This is just a test circuit what I need to know is: is the circuit correct, can this type of H-Bridge handle more than 2 Amps depending on the transistors used, and do you guys have any suggested modifications if it is wrong.

Gives all directions for two motors
I designed this circuit for those interested in controlling motors that require a lot of Amperage, but have gotten frustrated over trying to create a MOSFET … Read more

Issue with L293D

For some reason I can't get my H-bridge to turn my motor both direction. It was working a week ago when I was working on it. When I turn Input 1 High and Input 2 low it will turn the motor forward but when I turn Input 1 Low and Input 2 High and doesn't do anything. Well actually I can feel like a buzzing sound like its trying to work. I am powering the H-Bridge with it own power supply on pin 8 (Vs). Maybe something I'm missing.  I will tried adding some capacitor in to see if that help any.

Relay vs H-bridge question

most of the time I use an L298D motor driver IC for controling motors. However i find that the 1+ voltage drop is anoying. Some motors just dont go fast enough. 

Using a 7.2V power supply, leaves about 6V going to the motors and, as I understand it, the L298D is not designed to take in higher voltages. Although I think it can handle quite a bit if you cool it properly.

Yet another h-bridge question

I've been reading a lot about h-bridges, but I can't seem to find specifically what I need. I have a toy that I am hacking, and it contains two small DC motors. The toy is powered by a single AAA battery, and the motors receive almost the full supply voltage when they are turning (difference is about 0.02V). Their resistance is 2.6 Ohms, for a stall current of about  0.58 amps.

bi-directional speed controller

Hi all.

I am really new to robotics, and only just recently got my arduino uno. i've played around a bit here and there to learn how to control servo's and such, so i figured it's time for me to build my first robot. but in the design, i've come across a few problems:

Too high voltage drops across different TIP-based motor drivers?

So, I needed to drive a couple of mystery motors I've harvest from a "electric shaving kit". I had a big motor, extracted from the electric razor and a tiny motor extracted from the nose pliers.

My needs:

big motor -- drive it one way; small motor -- drive it both directions

Case 1: Handling the big motor

Move around on pressing the buttons on the remote
This was my second Robot that I built after I started making robots. Very basic r/c car which does not use any micro. Its based on a 8 bit encoder/ decoder and a … Read more
An ATmega328 and L293D based variable speed and direction motor controller
NTRODUCTIONThe GOduino II is a self-contained Read more

attiny85 h-bridge ldr robot

I have an idea for making an simple robot. Maybe solar powered... doesnt have to be...

I have an ATTiny85, an h-bridge from an arduino motorshield (L293D, I think) and some LDR sensors and some 3V-6V motors.

My question is, can I somehow put them all together to make a simple robot? If so, do I need anything else, besides simple resistors and capacitors? Or am I missing something?

Update 3-25-2012: So I used this simple code to program the ATtiny using the Arduino as ISP


void setup() {                

Question about SN754410 and current capability

As the SN754410 H-bridge driver is rated at 1A, am I correct in thinking that it can handle 1A at the max voltage of 36V and therefor will be able to handle 3A @ 12V and 6A @ 6V ?

Building Stair Climbing Robot and have power question.

I am building a stair climbing robot for a class that will carry a basket full of rubber stamps to the top of a staircase.  My robot will be loosely based off of this robot --->https://www.robotshop.com/letsmakerobots/node/8355.  I am planning on using an Arduino Duemilanove for the microcontroller.  I am planning on using 5 dc motors to power the four wheels on the ground, and 1 continuously rotating servo to power a wheel rotating at the front of the robot which comes into contact with the stair first and projects the device upwards.

H-bridge HELP NEEDED ! ! ! ! !

I searched every shop in my area couldnt find a single piece of H.so i thought to make it with logic gates as 7400 series is available. but before i buy i wanna know if my design is feasible? and is there any possibility of damaging of chip (logic gates).i'm using a GEARED MOTOR in my H-bridge

Phase one: Line Follower complete. Right now it is "learning" how to avoid obstacles the contact-free version.
Using a
INTRO This project -christened Deacon- is the next step in evolution from Nigel, who was abandoned last year. June 9th, 2011 Read more

cr4cX H-Bridge

The cr4's H-Bridge is builded with MOSFET and BJT transistors and specialized low-side driver IC.

In my tests the bridge has worked at 32KHz PWM frequency with virtually no heat generated.

Two of these (one for each motor) are used in cr4.

The bridge prevents the shoot through conditions and allow the following operating modes:

  • pwm cw rotation
  • pwm ccw rotation
  • pwm brake
  • brake
  • coast

Maximum supply voltage is around 18V and maximum current through the motors is limited by the IRF9540 MOSFET caracteristics.

DIY H-Bridge for Tamiya double motor gearbox

Newbie alert!

Hi all,

First forum post here. Go easy on me. I have not been able to find a solution to my problem in the forum, (even though a couple came close) so I´ve decided to go to the source.

Is this https://www.robotshop.com/letsmakerobots/files/H_bridge_single_relay_DPDT.pdf a good H-Bridge to use with the Tamiya double motor gearbox? If not, can someone point me in a better direction?

My apologies if this has came up before and I have failed to find it.



High Current Motor Control with Arduino

Hi All,

Please excuse the commercial but I wanted to let you all know about our new motor control shield for Arduino.  It is called the MegaMoto and is designed for motors from 7V to 28V and up to 13A continuous current.  A peak of >30A for a short time has been demonstrated.  The unit is fully protected against thermal and current overloads.

I'm sure many users would like to be able to control something larger than the tiny motors you can drive with the L298 etc.


The circuit I am using is attached.  I know the circuit works because it will move the motor forward and reverse on 9V.

When I apply 9V DC to it, things work as they should.  I can use my transmitter to forward and reverse the motor.

When I apply 12V DC from a lawn and garden tractor battery, the TIP 127s begin to smoke.  I have already burned one out.

After replacing the burned TIP 127 again it works on 9V but again apply 12V DC and more smoke.

L293D H-Bridge problem

Ok heres the problem, no matter what I do I can't get the H-bridge to work properly.

I've triple checked my connections, here is the test code i'm using

Schottky diode bridge IC for L298N?

Hi all!

Noob question: I'm using the L298N dual full H-bridge to drive my robot's 4 motors, can someone please give me the name of a chip that contains schottky diodes in a bridge configuration, so I can use it on the outputs to block back EMF? Sparkfun does the same on their boards: http://www.sparkfun.com/datasheets/Robotics/ROB-09571-Serial%20Controlled%20Dual%20Motor%20Driver%20-%20v11.pdf

I know that there are such ICs since I recall a friend using a 16-pin DIP in a similar occasion, but I can't remember it's name. I think it started with "L".

H-Bridge Motor Control for DIY Servo

I'm building a DIY servo for steering Yard Gnome. I'm testing some things out while I wait for the 24VDC 30 rpm 41 in-lbs gearmotor I ordered to arrive.

I'd like some advice on my controller.


H-bridge braking with L293(D)

I discovered how much braking power a Solarbotics GM9 can have when you short the terminals. I need that stopping power to make a robot that is suspended from a wire, wound around a spool, powered by a GM9.

But I also need to be able to power the motor in either direction. My platform of choice is the Picaxe 28 project board with a L293D motor driver chip.

How do I tell the L293 to short the terminals of the motor? I tried
high 4 high 5 ' both inputs high
low 4 low 5  ' both inputs low
but my motor will not brake.

Dual Y-Bridge (was One and a Half H-Bridge)

I had an idea tonight that is either inspired... or stupid. Please help me determine which. ; j

I was thinking about using one of my new Picaxe-08 processors for a project. They only have 5 I/O ports, three of which can be either an input or an output. However, for my project, I wanted to be able to control two motors and two sensors. Since traditional dual H-Bridge designs would require four processor outputs to control two motors with forward and reverse, that would leave only one I/O port left. Boo hoo.

Help with H-Bridge

 Hello, I need some help to reduce the chances of burning my precious Arduino/apartment.
I managed to build and test this H-bridge 

Trouble connecting Vcc2 to SN754410

I've tried looking around a bit and expect this to be a fairly basic question, but nonetheless I still can't get it to work. Basically I have an arduino connected to a SN754410 motor driver powering a lego motor. This all works fine until I try to use a second power supply (9V battery in this case) instead of the arduino's 5V output. Here's the current setup:


SN754410 Test LayoutNote that the arduino is running off of USB power.

The darn H-bridge

I just want to be able to reverse a current. How hard can it be?

I just want to be able to decide direction of the motor to my pic, why does it have to be so complicated?

Well - perhjaps it doesnt! Jip / Jimmy, the most clever guy in here just drew me this and send it to me.P2290333.jpg

The smallest and most-likely-to-burn-something H-bridge in the world!

If it works, I will make a full walkthrough about it.

If it burns my robot.. well.. he did warn me ;)