Let's Make Robots!


I just received my OSLRF laser Range Finder!

So I received this awesome package in the mail yesterday from LightWare Optoelectronics in South Africa.

Print PCB's on photoresist materials with a blue-ray pickup
Using a
  About a year ago my brother and I engaged on a quixotic project to build from scratch a low-cost PCB printer for photoresist.  Read more

The LM-317 Voltage regulator problem

Well, recently I have been attracted to laser diodes. I am trying to make them work. Here is what I learnt-

1. LASER diodes are pretty current hungry,it will eat as much as it gets,since it's internal resistance is pretty low.

2. To make LASER diodes work properly, you need a CONSTANT current source.

3.Red Laser diodes need 3 - 4 volt to run.

4.You can make a Laser driver using LM-317 (it's called DDL)

Identifying LASER diode pins

I have found a Sony AD-7280S DVD-RW drive,and the laser inside it is in working condition. I have taken it out,but surprisingly it has three pins. I want to know the pinouts of this specific diode. As reverse current for the Laser diodes is only 10uA max,I can't take the risk of trial and error method. The laser Diode has the three pins named as "D","G","C". I wonder what do these letters stand for.

The Service Droid is a new robot kit I am designing. It is intended to be a low cost, D.I.Y. robot chassis with two 3 DOF arms. The gripper on the right arm is … Read more

IR Laser Sensing

Would one of these pickup a 38khz signal pulsed from a 650 nm laser?


Speach Synthesis, Speach recognition, face recognition and face tracking, autonomous navigation, remote controle
Using a
Hi Everybody! Few times ago I bought a Robot Vacuum cleaner (Neato) for my house. It wake up my old passion for robots which have been in sleep for years, after an … Read more

A hexapod for my son to ride on - a big experiment

After seeing the weblink by bdk6 "inspiration for Hexapod builders" I was inspired. The video is of the "Mantis" turbo diesel all terrain hexapod.

Ok, I cannot afford to build a 2 tonne turbo diesel hexapod but I can build one big enough for my 8 year old son Shi Sen to ride on. My plan is to have almost the entire robot laser cut from 6mm plywood.

Plays Tic Tac Toe, Participates in Oddbot's Naughts and Crosses challenge
Using a
UPDATED 2/28/13 Before you read this, please read the post on my other Tic Tac Toe playing robot: The Ttp Project at: http://letsmakerobots.com/node/36073 Read more

Laser tag


I am planning on building a lasar tag set with my arduino. does anyone know what I could use to detect the lasar ( some sort of reciever or cell of some sort) I want to be able to use it when there is light so a photo cell is already out of the picture.

What do you think: do search engines do only good or do they limit, too?


I'm putting this before you because if you're reading this, chances are you're brilliant and well-qualified to add insight to my thinking about this matter.  For reasons that will become apparent shortly, I was going to request that only older LMR members contribute to this thread-but as CtC recently pointed out we have some very intelligent and able younger contributors, so it be behooves me to ask for everyone to mull this one over and put it out there.



So I love lasers. Really, really love them. I've bought about a dozen different types of laser modules (green/red) to play with on my next bot. However I'm at a loss as to where to even begin on using them as more than just a "frickin laser beam", and have it actually DO SOMETHING!

3D Laser scanner for 25USD

Believe it or not, but in China the people really can do things with less money then elsewhere in the world. Cheap 3D Laser Scanner for roughly 25 bucks. See that amazing results...

Investigates the Festive environment with a Festive Twist
Using a
I present to you "Miranda" , a laser scanning Robotic system using a Wii-Mote Camera and Festive Reflective Xmas Bauble. My previous "Halo" Experiments have been … Read more

Captains Blog ....StarDate 29773 ......Containment Leak in Gareths Space-Lab......

Scotty ......"Captn....i canny noo contain the plasma leak.....were doooomed"

Kirk......"We need one of those new Halo things ......can you build a "mini" one Scotty ......in purple" ?....

Projects a laser generated "Halo" on the floor .... as an object detect system
Using a
I present "Halo"  ..... my latest Laser Robot It been almost a year now that i have had the idea to cast some form of "Halo" around a robot and detect the … Read more
this is a test device,hand made ugly style.i am trying to make it as small as possable. part list: 300mw laser diode lens diode driver 3*AA battery mini … Read more

I need advice for a power transistor

Hi all,

Since DanM posted his laser blog I was hooked to the idea of pulse driving laser diodes.

I have created my own pulsing hardware using an ATMega328 to generate a 62.5 ns pulse at 16 Mhz, driving the diode trough an ULN2803 (Toshiba made) which seems to be able to respond well to such short pulses. 

However the ULN2803 is limited in power output so the highest current I could sink is about 700mA (I know the ULN2803 is limited to 500mA yes) by parralelling outputs. At this level the ULN2803 is way over its limits and starts overheating.

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
This is a simple Arduino Light seeker. It has an Arduino Duemilinove on board. It is powered by 2 AA batteries for logic( with boost converter), and 4 AA batteries … Read more

Detecting laser beams?

Using an Arduino, I guess I would modulate (PWM) the laser module and have the photocell light sensor pick up the frequency. Would this work?


Turns on and off whatever you connect to it
There are already some great projects on the internet about hacking home automation systems, but what I wanted to do was to control my plugs creatively. Thats why … Read more

IR v. Sonar

I've been making plan for an obstacle-avoiding robot, and was originally planning to use a Sharp IR range finder for it (10 - 80cm), but after seeing other sonar range finders, and other people's projects (the majority of the ones I see seem to use sonar), I was wondering:

Which is better: IR or sonar?

'Cos IR recievers can be affected by ambient IR light, and the best i;ve seen goes up to 150cm, whereas I;ve seen sonar ones up to 7.4m, roundabout, and they can't be affected by ambient sound (I think).

Bender is a medium sized robot based on the Crustcrawler Nomad HD platform. It uses the Parallax Motor Kit with Position Controllers, a pair of Parallax HB-25 Motor … Read more