Let's Make Robots!


Joule Thief

There is not much to document in this project. I built a Joule Thief....who didn't ;-)

Mine is powered by a LR44 button cell (1.5V) and it light up a white LED which usually needs a minimum of 3.3 voltes to light up.

I just built it to test how long the LED can light with this one battery (it might be interesting for throwies). 

Will update the blog when the battery is completely depleted.

Power on time: January 14, 2012, 3:30PM


May I introduce myself, I am TinySpider. I was build a couple of days ago after my creator got some ATTiny and needed to try them out. I was inspired by this  http://www.instructables.com/id/Computer-Bugs-Additional-Ideas-Tips-Tricks/step15/4-Spider/  

Basically I am a bare ATTiny85 some copper wire, two LED's and one 3.7V/50mAh LiPo battery.

The heart lights up when you hug him
Hi, this project was my christmas present to my girlfriend this year. What it does is that every time the bear is hugged, the heart fades in, pauses, and then fades … Read more
This is my first Pummer I have successfully build and I am pleased with the work. It is a simple two LED pummer. Took me nearly 10 hours to complete due to the fact … Read more



So i have a IR detector and it is hooked up to an arduino i have programed it with the help of this blog http://www.arcfn.com/2009/08/multi-protocol-infrared-remote-library.html i am doing the example that is named " How to recieve" 

Problem: whenever i click a button on my remote the number 0 apeers on the serial monitor. What does that mean?

Scroll the text without using any controllers or other components on the matrix except the arduino/picaxe and the matrix, and ya dont forget the current limiting … Read more
Blinks in different programable patterns
My first step to robotics.... an 3x3x3 cube Read more

ok i think i have a phototransitor... over 500 of them or diode

right i have recently found out that i have about 500 photodiodes or phototransistors. 
however i have never used these before and i dont really know what they do or how they work, could someone please explain what i can do with them and what use they are to me.






i dont know what this LED is ... any ideas ?

ok i have a few of these LEDs and i dont know what they are for i think they might be IR LED, i have tried putting a power source through them from 3-9V and it does nothing. any ideas at all i have about 500 of these my friend gave me and not a clue what they do... 

Plugs into the accessory port of the bigtrak Jr, and lights up when you tell the Big Trak Jr to output
This is my very quick hack for my brand new Big Trak Jr. The Big Trak Jr could be an awesome platform for hacking. At $24.99 +pp from thinkgeek, you can't go … Read more
Provides a compact way to add LEDs and sound to a small robot.
SoundnFury is a small electronics module with a piezo speaker and four red-green LEDs installed on a round Radio Shack circuit board. SoundnFury provides a compact … Read more
PIR motion sensor and also other useful stuff like motor with gears, LED, switches, 3 AA batteries and connectors
Hi! A friend of mine reminded me of a cheap source of electronic components that can be used in robots. And the best thing is you can find it in every … Read more

Question, can servos "leak" power?

Hi LMR! If you haven't seen my robot MAEP already, it has two power supplies, one for the motors and one for the Arduino. I decided to add an LED indicator to show when power is being supplied to the motors (which are servos). The LED is just connected in series with a 1k resistor to the power lines from the motor power supply, a 4.8V NiCad battery. As you expect, the LED is off when motor power is off and on when the motor power is on. But when just the Arduino is on and not the motors, the LED is lit dimly, and changes brightness as I wave my hand over the sensors.

  Here I will try to help begginers with the most attractive electronic device the LED. :D First of all the definition of a LED: An LED or Light Emitting Diode, … Read more
guide light, conduct air, be tubey
When your project, like mine, needs a tube pipe to fit exactly around something, consider making your own. I could not find anything with the exact inner diameter … Read more
Flashes LEDs in cool 3D patterns
Using a
Video 3: Completed LED Cube with 8 patterns           Read more

Charge Capacitor with Solar Panel

Is anyone aware of a simple circuit that will charge a capacitor with a solar panel (Small one from calculator) and then discharge to an LED via a transistor when the capacitor get's fully charged? The point is to make the LED flash. The frequency of the flashes would depend on ambient light conditions (less light, longer charge time). The closest thing I found is the circuit bellow. Would replacing the +12V with a solar panel still make it work (just take longer to charge)? Also what is the N.C. symbol at the transistors base ?(No Circuit or Normally Closed???)

How to wire up 6 led's on one 20mA pin question - SORTED

Edit 02/11/2010


And what a buzz when it worked.

Thank you all so much for your help, especially ignoblegnome (+others). I have yet to fit the board to my bot, but will do that tomorrow.

Although it uses the same chassis as my first robot, it is entirely different. I am trying to do an AmandaLDR as fritsl's, (except with LED's), so I will probably put it in the robot section (if it works).

Can't figure out how this 4 digit display works


Sorry this isn't really a robot related question, just an electronics one.

I was cruising through a local electronics shop. They have lots of salvaged parts. They had a whole box of old 4 digit LED clock displays. Since they were only about $3, I picked one up. My son wanted to build a clock.

After working through all the connections, here's the schematic.

A cheap LED matrix driver run by an Arduino
I’ve set out designing what I’d like to call Arduquee, a Arduino powered Marquee. The idea is this, low cost LED matrix driver boards that are easy to work … Read more

LED cube the start of my robot

i would like to make a LED cube like the one in the video a 3x3x3 cube

how ever i need to know abit about pic microcontorollers and i dont know what i should use

i have looked online for help but i dont know how they work

also i know this doesnt have much to do with robots but i plan to make one and have it interact with the cube

soo im starting with the cube any help would be great thank you

Minimal Picaxe LED blinker

I just found a different way to make an LED blink with a picaxe 28x1:

   inc b0
   let pin7 = b0 >> 7
   ' do other important stuff here
goto main

Learn how to use your Arduino, and blink an LED
Hello all! In this walkthrough, I'm going to show you the basics of the Arduino and how to blink an LED. I know this has been done many times, but since I'm hoping … Read more
his head is an LED and turns on only when there is no light !
Not only does he look human , he is also a functioning circuit ! his head is an LED and turns on only when there is no light ! he has got a mind of his Own ! :) … Read more
Emits bright light and loud noises =D
Around the end of February every year there's a 'Chinese Lantern Festival' that happens in my city. Lots of junk to buy, cool lanterns, interesting food, and most … Read more