Let's Make Robots!

LEDs

An iteresting light show
A modified USB flash drive. I added 2 multicolored IC controlled LEDs from a Thermaltake 120mm PC Fan. The LEDs are linked in parallel and are in series with a … Read more

My 8x16 led matrix

UPDATE:  6 Oct, 2013

Ok, I have been too lazy to update this as this was done a month or so ago. I hereby declare this project complete. It is now bigger and better! Below are some photos and a video of the completed matrix and driver board(click any picture for a larger view)-

The Matrix-

The driver board (front) -

Infrared diodes and detectors make things fun and magical. We are use to touching or flipping a switch to turn on lights. A simple transistor circuit with an … Read more
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
Navigate via ultrasound and light, controlled by IR.
Using a
  Hi, This is my first project and I am a big dumb in electronics... :) so, if u see I'm doing or saying something wrong or stupid please tell me :) Mr. P stands … Read more

Funny behaviour in a picaxe...

Hi all, I hope people can help with this, cos I'm baffled.

I've been using a picaxe 08M2 (the new one) to control a stepper motor, which works fine until I want to use the free input to trigger the motor.

When I do that no input affects what the chip is doing

I took it back to the program, nothing odd there, so I tried using a pushbutton switch to turn an LED on and off.

If I use this program:

main:

if pinC.3 = 1 then

high 1

LASERS - just a bit about them

Just a couple ideas for those who are set on experimenting with lasers.

FIRST and most important: Lasers are dangerous. I am not espousing that you do anything with lasers, as you can be blinded BEFORE YOU CAN BLINK, if you use lasers stronger than the common "keychain" laser pointers.

Devices not used to their full potential

It seems to me some very cheap devices are not used to their full potential in robotics. Currently I am focused on optical mice. There are tutorials on the web and even an easy to use PS2 library for Arduino but I never see a robot on LMR using them.

I am currently experimenting with a cheap PS2 optical mouse as a high resolution quadrature encoder. With a resolution of 800 DPI, I can get an accuracy of 3600 counts per revolution (1/10th of a degree) by having the sensor mounted near the outer edge of a disc about 40mm in diameter.

hello i want to know if my circuit would work in real life

hello
im building a flashing heart for my girlfriend, im using a 555 chip and 7 LEDs

i have a circuit lay out from multisim it says it will work but i have my doubts 

 i wanted the potentiometer to change how fast the LEDS flash on  multisim  its always the same soo im not sure why 


im using 10 mm LEDs  

Christmas mini project.

Well i have an idea in my mind about a mini christmas project but i dont know how to make it.

The idea.

It will be an arduino with a buzzer ,a small lcd display (16x2 probably) ,a big red push button and some red leds.

What this thing is going to do ?

Every time you connect it to your pc though usb port and you push the red button it will tell you how many

days , months,minutes ,etc are left for the christmas eve ,new years eve .

Fading an LED with hardware

Hi guys,

I am trying to get an LED (attached to the i/o port of a microcontroller) to fade in and fade out without using PWM.  I hooked up a resistor and LED pair in parallel with a large-ish polarised capacitor, thinking that as the cap charged it would prevent some current getting to the LED, resulting in a fade up to full brightness.  When power was removed the cap would then slowly empty it's charge through the LED, resulting in a fade out.  It worked for the fade out but not the fade in; it simply went to full brightness when power was applied.

How many LED's can you control?

Hi All!

I've got in mind a project that will involve a couple hundred LEDs that have to be independently controlled. I want to  make a clock where the individual seconds, minutes, hours, days of the month, and months of the year are represented by a lit LED. As the LED's representing seconds passes 60 seconds and goes to the next minute, all the "second" LED's go out, one "minute" LED turns on, and the seconds start over with all of them being dark. The process repeats indefinitely and cascades into hours, days, months. 

Fades and flashes and keeps away the closet monster
Insired by Geir Andersen's RGB Nightlight, I thought I'd build one for my daughter. She's just started having nightmares (she's 3 years old) and wants the lights … Read more
Tells you what pipes to hit to play certain songs
Hi, this year I attended the 2010 National Scout Jamboree. My troop's gateway theme was The Blue Man Group, so we built PVC pipe instuments for people to play when … Read more
Forget making a LED blink. how do you even get it to turn on? This is a walkthrough for making an LED turn on and off at will, in a small beacon for a robot's … Read more

Blinking an LED in about 5 to 10 minutes

Earlier today got a FedEx delivery of a MakerShed order placed last week. Toys!

 cap_006.jpg

 One particular toy was a new Arduino Duemilanove. Had to see what made the Arduino popular.

 cap_005.jpg

A tutorial for calculating series resistance and reading LED data sheets
I've noticed that some people are uncertain how to calculate series resistance for a LED or when using a group of LEDs are uncertain about wiring them in series or … Read more

Easy Freebie LEDs

A quick tip for all you cheap skates out there. I've always had it in my head that I would like my robot to have no permanent connections, to allow me to experiment and reconfigure. This also has the nice side effect of less soldering for me to mess up. I actually have a cunning plan to pay my flatmate in jelly beans to do the tough bits for me; he's an electrical engineer (rock!).