Let's Make Robots!


Driving One Stepper Motor With L293D Using Two Pins

Question: Is it correct, that when I solder the following circuit there are only two pins nessessary
from the microcontroller to the L293D to drive a unipolar stepper motor ?

Answer: Yes. That is correct.

Question: Are the two NPN transistors and the 10kOhm pull-up resistors responsible for the signal inversion?

Answer: Yes. That is correct.


  da Vinci is an etch-a-sketch robot. He is capable of etching low resolution images in grey-scale. Let’s get to the build process.   I first went searching for … Read more

Small stepper motors

Hello LMR,

I need to get two motors which I can control precisely, like in a CNC.

I've been looking for small stepper motors and found these, which Pololu sells:


They seem to be good but I'm not sure about their speed (I've read somewhere that the are low speed and I would prefer fast motors).


Line Laser scans object while recording position of laser with software. Allows capture of 3D object into software.
Using a
Intended for use with David Laser Scanner software. After completing the CNC machine, I decided to build a scanner using my new machining ability. Using an Arduino … Read more

H546 Unipolar Stepper motor driver

Hi, ive been trying to make a steppermotor driver for 2 http://www.active-robots.com/products/motorsandwheels/stepper-motors/datasheets/103h546-0440.pdf

I have used a ULN2003 like this:

(the second motor is in 5, 6, 7, 8 (I have a bigger ic)

Run 12V stepper with 5V??? [SOLVED]

Hey guys I have a quick question. I've never used a stepper motor before, but I have one that will fit my new robot nicely. It is a 12V motor kinda like the one below

12V stepper motor

I don't have a 12V power supply right now, only a 5V. I want to know if this motor works before I go and buy a new battery. Does anyone know if it will even work with 5V? I just need it to move just enough to let me know it works, then I'll go get a battery. 

Mixed power sources, stepper motors, arduino, and pololu stepper driver

I'm building a 3D printer and I'm a little over my head. Right now I'm trying to make sure most of my components play nice with each other with some simple code and only one motor.  Here's my set-up:

Seeeduino Mega fully Assembled

I have a seeeduino mega. More on the pinouts later. It's being powered via USB and I don't know if that's okay.


Molon Mystery

  Here it is. Chess Robot V2. Version 1 had many problems that i tried to fix with V2. I also wanted this new one to be simpler than the other one. So then came … Read more
For now its almost done! My selfbulid CNC-Mill is ready to use. It all started during my x-mas holidays when I found Tinheads Valkyrie here on LMR. I had the idea … Read more

Timers and ... stuff

Hi all!

Been pretty busy lately digging in the big black timer.pngmystery box called Timer  on those nifty AVR controllers.

I think I finally have a clue how they work, and more then that, how they can be put to good uses. 

One application I'm going to do now that I have a clue, is to (try to) do microstepping. Yeah I blabbered about that other times too.

This mini stepper motor from the Electronic Goldmine was ridiculously cheap. However, it is wired strangely for a stepper motor, so I've collected some more info on … Read more
For now it draws the shapes provided, eventually it should cut them too - actually does do cutting now :D
Using a
Hi all,  As OddBot suggested on my blog I have created a robot page for this thing. I will update this page with more pictures schematics, code and video as soon … Read more

Yet another L298 based motor controller

Hi all,

motor controller

















 This came out as a sub project related to my DIY CNC machine "the Beast"  because the outputs of the Arduino would not suffice to control the motors. So I chose to use I2C for this purpose and designed my own little guy.

I'm afraid I'm STILL on the Write LMR trip. It's not got tired yet. I've decided to motorise a miniature Etch-A-Sketch. I decided on steppers. Not servos. Servos … Read more