Line Following robot in a mouse.

Got some old malfunction mouse? Let's make it as a line-following robot!



Link:
Mouse-Bot

PAL TV game only need one ATmega!

It is an open source project called "AVGA", which uses only a single AVR ATMega168 to create a super mario clone. Schematics and firmwares are provided freely!


Link:
http://avga.prometheus4.com/index.php?p=2-3

LED used as touch/light sensor

LED is a light emitting diode, it is commonly used as output device. But by connecting each end with GPIO, you can use it as input device with some software tricks. This idea is cool, and I remember the first time when I got this idea was from the cool research site "Multi-Touch Sensing through LED Matrix Displays", you can find the information here:
http://cs.nyu.edu/~jhan/ledtouch/

Recently, I found someone use the same idea to implement a LED input sensing demo with ATmega8, it is very interesting.

Research on accessing SD card with AVR.

Using AVR as a data logging system is cool, but data storage is a great problem as external eeprom or flash memory may be too small and expensive. I guess most of us have some 16MB and smaller SD card on your desk because nowadays you are using 2G SD cards on your camera!

Here are some links may useful:
http://www.captain.at/electronic-atmega-mmc.php
http://www.avrfreaks.net/index.php?name=PNphpBB2&file=printview&t=61851&start=0
http://www.roland-riegel.de/sd-reader/doc/index.html

LED coffee table by SparkFun!

They really worked very hard on this cool LED table!

Youtube demo:


Link:
http://www.sparkfun.com/commerce/news.php?id=188

Gif2led released, and with AVR LED Egg demostration!

We have worked on LED matrix for so many times, but mostly for text scrolling, so how about make some animations on it? But we are too lazy to make the animation patterns to the C header file in an array of bytes. We finally finished one tool may be useful for all led matrix lovers!

The gif2led project is written in Ruby, required Rmagick library for gif manipulation. It is mainly designed for 8 or less columns matrix, for instance 8x8 matrix, 10x8 matrix, 5x7 matrix etc. It output an pattern header file with a 2D array frame by frame from an animated gif input. We only tested with AVR-gcc, but it should be useful for other MCUs too. You can find more information on the gif2led project page, http://labs.bitartist.org/gif2led/

Let start with our demonstration, the project is called LED Egg, it is based on a 10x10 matrix (but we only use 10x8 in our case) with an Egg case to hold the circuit board.

To prepare the animated gif, we use macromedia Flash, and here is the screenshot:



Noted that the frame 0 (marked as CAL above) is a special frame, which used for calibration. When used with gif2led tool, the frame 0 is the pattern of your led matrix with all led ON.

and then export the movie to an animated gif:



Then simply run the following command, we can obtain the 2D array header file:

ruby gif2led pattern.gif 20 > pattern.h
//selected ratio is 20.0%
//Cal result: LED Matrix (row*col) = (10*8)
const unsigned char pattern[63][10] PROGMEM = { //Frame 0 {0x42,0x00,0xa5,0x00,0x84,0x21,0x00,0x42,0x21,0x84} //Frame 1 ,{0x00,0xa5,0x00,0x84,0x21,0x00,0x42,0x21,0x84,0x42}
...
...

#define MAX_FRAME 63
#define ROWS 10   

Now, we have to prepare the circuit part, we use AVR tiny13 together with 4017, please refer to the circuit diagram<here>. 4017 is used as a row counter, and such that we can only use 1 pin for row shifting. The remaining 4 IOs of the tiny13 would use for column output, we are using 10x8 matrix this time, so we assume the pattern is symteric to save pins, so 1 I/O drive 2 columns in our case. The circuit showed below:



So Lets add an egg case, the egg is made from pu foam plastic, it is used for Easter decoration.





Video demonstration:


Close look on the LED pattern:



To download the gif2led tool, AVR source codes, and flash template, please find in the following links:

Gif2led project page:
http://labs.bitartist.org/gif2led/

Gif2led Rubyforge page:
http://rubyforge.org/projects/gif2led/

Philips LED Lamp Featuring 16M colors!

Wow, philips worked on many LED products recently, and here we have a LED lamp for your living room.
May be someone can use for some art projects. The controller is very cool, it is a touch wheel and you can change and set the color easily. May be you can try to set the color to reflect your mood everyday. Enjoy.



More Info by unplggd

DIY EL BackLit Photo Frame.

Electroluminescent(EL) technology always uses in the backlit of small LCD. From wikipedia:

Electroluminescence is the result of radiative recombination of electrons and holes in a material (usually a semiconductor). The excited electrons release their energy as photons - light

Anyway, it is good for lighting.

I got the EL panel in a local store which should be powder phosphor-based electroluminescent panel. It is a 3.5" x 4.6" white light panel.



It included an adapter for converting 12VDC to AC for the EL panel.

Let's see how we can make use of this EL lamp.


1. Use for slice viewing


2. Put a Post-It on it, and you can see a growing Post-It in the dark.


3. For home lighting, illuminate your Toys.

4. A BackLit Photo Frame

Step 1 -
To make a DIY backLit photo frame, you can get a large photo frame in store or you can make one yourself. Here we are:


Step 2 -
Glue the panel in the back cover of the photo frame. You can see there is about 1.5 inch space between the photo glass panel and the back cover. We like to have some distances apart the EL panel and the glass to diffuse the strong illumination of the EL.



Step 3 -
Power Up.



It looks alot better on my desk, sorry for my poor photo skill. Let's see the photo frame in action in the below youtube video. Enjoy It.

Anyone who want to get this EL panel (3.5" x 4.6"), We can order it for you. It is only US$15, and $5 for shipping to US and Canada. For payment, We use paypal. Please contact us: order@bitartist.org

Hydrogen Fuel Cell Toy Cars.

Hydrogen fuel cell is the next green source of energy, by breaking down water (H2o) into hydrogen (H2) and oxygen (O2), the hydrogen can be used for energy generation afterward.
It is still a long way to go in normal usage, but how well is the technology now?

Horizon Full Cell Technology introduced a Toy Car using their fuel cell technology. You can buy a toy car in affordable price to taste this bleeding edge technology.


Check out the youtube video:





Links:

Horizon Full Cell Tech Toy:
http://www.horizonfuelcell.com/tech_toy.htm

RC model:
http://www.horizonfuelcell.com/rc.htm

Wind-Lit ( A wind activated Lamp )

This "wind bell" shaped lamp is called "Wind-Lit", created by LivingWorld.net. There are few LEDs inside the case, when the wind blows that making the bottom place move, it triggers the LED to grow. It is a nice idea to make a growing LED project with wind activation which provides some random effects and most importantly the link between the nature and you. The new version included a solar panel charging in day time, and the LED grows at night time. It is a prefect product for your garden.

It was also demonstrated in a cafe in Japan:


The effect is fantastic:)

Project by http://www.livingworld.net/

Table Lamp Solar Charger (Solar Charger Test setup)

After studying how to make a simple solar charger, I decide to make a fast prototype to test. I got one solar panel a long time ago, the ratings of this solar panel is unknown. The solar panel will output different voltage and current under different lighting condition, so we have to measure it before use. I measured this solar panel would output maximum 3V under bright sunlight, and output 2V under my table lamp.

Everyone got a table lamp when working in front of the computer, and the light condition will remain considerably constant when compare to the outdoor sunlight condition. It would be easy to make one simple table lamp charger.

The above diagram is my setup, I used the schottky diode (IN5819) to prevent back current flow to solar panel when the lamp is off. The diode is placed between the solar panel and the the battery holder with two AAA batteries loaded. When charging, I measured the forward voltage across the diode is 0.14V which is small when compare to a normal diode.

Initially, the voltage across 2 batteries are 1.7V, after a while the voltage is 1.81V, so it is charging right now. The charge current measured is only 0.12mA.



The current is too small, and not so sure how long it will charge up to 2V:)

Small 5x7 Dot Matrix LED display

What is 5x7 dot matrix display?


5x7 dot matrix Led display is usually used to cascade together to make a large led matrix display as you see in train station.


(A typical LED matrix display)

The small size of 5x7 dot matrix led display is good for small electronic project, typically the 5x7 dot matrix is used to display one character a time, i.e. 5x7 dot matrix font. In order to use only one 5x7 dot matrix to display information, we have to use the 5x7 dot matrix horizontally. We use the 5x4 dot matrix font instead and of course text scrolling will be necessary.

The KAAS Led flower vase is using the 5x7 dot matrix display for displaying messages.

kaas used one AVR tiny13 and two 74hc595 chips to drive the led matrix, the result is very impressive. The detail information of the LED flower vase is here.

Another interesting project is the Twitter LED scroller Build from davidnin. He used the Arduino board and one 74HC595 to drive the 5x7 dot matrix led. Please check out the cool video:

Another project from us, GIF2LED!
it allows you to convert a gif animation to LED header file to speed up your coding time:)

Check it out:
http://www.bitartist.org/2008/06/gif2led-released-and-with-my-led-egg.html


Another cool tiny message scroller using ATtiny2313 from kalanda:

http://www.kalanda.com/scroller-de-7x5-leds-basado-en-micro-attiny2313.html

Solar Power, the green power source.

Solar Power Charger

Solar power is not a news nowadays. People are finding better ways to get power without harming the earth. To use of solar power, you need the solar panel that converts solar energy to electricity. So how to make a small solar charger for your home use? This solorb's website teaches you how to make a simple AA battery solar charger, few components are needed, a nice choice for your home project.





The project needs few solar cells, and 1 1N5818 Schottky Diode and of course the AA rechargeable battery. Why Schottky diode? this diode have less voltage drop when current flow through, it is important as we want to be sure the energy is not wasted on the diode which is only used for preventing the current through back to damage the solar panel when the charger leave in the darkness. You can also buy the solar kits from the author website as well.

Take it into real life application, you may add the solar charger to your radio! Let's read the tutorial bought you by gotwind.org "DIY Solar Powered radio for $5", the theory is the same as the AA charger.



Another video showing a home-made solar USB power charger:

Solar Powered USB Charger - Cheap And Easy To Make! - The most popular videos are a click away

A very comprehensive study on Solar power charger: REUK.co.uk - Solar Battery Charging.

Red Led Bubble From the 70s.

I found this special Red led bubble in ebay by (powerandlight).
It looks so cool to me. I didn't see this led before, I found out that it should be similar to one used in TI-59 or other old calculators in the year 1977. It was not in production anyway.
Each bubble can display A-Z and 0-9. It should be the same as 15 segment LEDs nowadays. I hope it can be larger otherwise it is so small to use as a cool display.

Jeroen used the AVR ATtiny2313 with 74HC595 to drive this cool red bubble, as he called "Starburst Led" project:

Robot idea from natural creatures.

It is one of my favorite video from http://www.newscientist.com/, it talks about the robot research around the world that using the movement technique from different kinds of animal. It is really amazing to see all these robots moving. It is really Real.