Let's Make Robots!


add.pngSubmit Something else Did you make something else? Show us


Hooking up a computer to a servo?

So I've seen some people using a laptop as the brains for their bot as opposed to a microprocessor... but here's my question... how the hell do you hook up a servo to a laptop? What do i need??

Google sketch-up: entering absolute coordinate

ok, i'm trying again with sketch up

now, i want to move an object to an exact location, x,y,z. not just moving it around with the mouse.

how do you do? i read the guide and it says something like entering [x',y',z'] on the value box, but i have a problem with this: for making the brakets [] i have to press the alt button, that automatically interrupts the command so i'm unable to move.

Also, how do you see the exact coordinates an object is ?


Voltage Regulator?

The 3 volts from 2 AAA's that I was using for my small project isn't enough to make it speed across carpet due to the voltage loss across the components.  The motors end up getting about 2 volts instead of the full 3 they need to even move (I've tested it).  So, I wanted to just throw in another AAA and bump the whole thing up to 4.5V (I did the math ... all the components, including the LED's, would be fine).  Only problem is ... the robot (Blinky) is so small that there's no room for another AAA battery.

Flyback diodes

Hey all,

Fairly noob question here: Can I use diodes to allow multiple output pins to control the same actuator? In other words, is THIS possible?


Help with IR Sensor LED020 (UPDATED)

Attached are photos of my circuit on a breadboard.



I posted a video. Ignore the TV in the background. When the universal remote sends a signal it is decoded by the PICAXE (not done manually I found a setting that the sensor can read and decode itself). A LED flashes to show a signal was read. It then shows the number of the code that was sent in the debug window. In a few days I will delete this post and add a turorial. Then its off to making my robot WOOHOO.

Finicky ULN2803 Darlington driver

So I've been using the darlington driver in the 28x1 starter kit, which has been quite nice. When I decided to build my own circuit, I moved the chip to my new board, with the EXACT same vcc and ground hookups, and get nothing.

What I'm curious about is does this chip's leads need to be all connected? I just have ground, vcc, input 1, and output 1 hooked up. Like a chip that even if you only use one pin, the other need to be connected to something to tie it down to a high or low output?

My head hurts from trying to figure this out. Any help would be appreciated!

hobby motor control

Hi guys, I am looking into getting a small electronic speed controller from the rc hobby store to run a couple of small dc motors (tamiya dual gearbox), does anybody know if these take the same pwm input as running a servo or does the r/c gear use something else? I thought r/c gear used pwm but when browsing online for motor controllers some say pwm, and some say r/c (in addition to analog or serial or whatever else). Is there a difference?

Beginner + Linux + AC89C4051

I am a total beginner at both programming and robotics (I have been using Linux as my sole OS for the past 4-5 years, so I've been plenty exposed to programming and programming languages).

A few days ago i got 4 * AT89C4051 chips from a friend as i told him I was thinking about jumping in to the robotics world. But i need a programmer circuit for them, Atmel have a list of official distributors of programmer but they are rather expensive and only seem to work with Windows.

Help with Schottky Diode


Just don't want to screw this up...



Which is correct? A or B?

hacking the digital Sharp IR sensor

Check out this link, Ladyada bought a digital IR sensor by accident, and found a way to turn it into a analog one. Clever!

And an interesting aspect is that the D version is often cheaper than the A versions.



Sony Rolly

Looks like a fun little toy. I'm wondering if ti responds to any sound. It would seem really difficult to have it respond so fast to random sounds.

SRF05 and Picaxe sound

I feel really silly asking this. I saw it in a comment while browsing the site, and now I can't find it again!


Someone posted how to get funky sounds from the picaxe by using the sound command and the input from the SRF05.

I'd really like to mess around with it, but there's not much documentation I can find about further utilizing sound.



... Are Belong To Us

Know your meme! Rocketboom is funny for so many reasons. This is a must see for anyone wondering about or using that frase "All you base are belong to us!", or variations thereof.

Two SRF 04

Hello again. I ordered those two without any additional servo motor, so I have to put them to dedect left and right.

 How can I calculate what is best angle to go with? Or design? Also i have two DC motors with gears and stuff, they work well. 

  I was thinking one front and one back, but if I had atleast one servo. Or two in front, everyone in their angle.

society of robots carpet monkey


Nice little creature with legs on wheels. Or something like that. It doesn't jump, like Fritsl's creatures, but it is nice to look at. And to gawk at the fabricating techniques this guy masters.


Help with basics on a gumstix

Hello everybody, first sorry for my english!


I am here because I need some help programming my (first) "robot"... The idea is that I have a gumstix (verdex XL6P RoHS) at free use and that for further use, this is the best solution (need calculating power, for small and light cards...)! I am now trying to understand how it works and how I can build a embaded system to work my robot well...

Soldering iron not hot enough?

I've got a really crappy soldering iron so that very well could be the cause of my problem, but I want to be sure before I head to Radio Shack and drop some cash.  See, I know that you're supposed to heat the connection and then apply the solder onto the joint, rather than putting the solder directly on the iron and letting it melt.  But when I use the correct method, the joint doesn't get hot enough for the solder to melt!

Cup recognition for cup lifting robot

So I'm going on to improve my robot and hopefully he'll become far more advanced but in the meantime I was hoping to model the fritsl's "Bernard the Cuplifter" robot.


So here's my question. I was thinking of how to script to recognize a cup to lift. 

 here's my idea. Let me know any alternative ideas or imput on it


If there's an obsticle center move head right check distance is > center

If distance > center on the right then pan head left check distance > center

Soldering :P

Hello, i need help :)

I have a perfboard, of the kind with all holes isolated from each other, like this one. I then have two of this male header strip inserted on the perfboar, parallel and spaced by one empy hole row. Now i have to solder the pins of one line with the one of the other, it making many 3-holes connection bridges (i hope i explained clearly).

Budget Robotics "Rigel"

Has anyone here tried this platform?  It has some possibilities, I think.



Duane S

Wilson, NC  USA