JUL13
Hacking iButton vending machines
Very popular 1-wire protocol from Maxim is used for many of their products as well as for their iButton. iButton is an integrated circuit with various options such as read-only serial number device, memory device, temperature loggers and so on. The latest use is in vending machines where it stores credit or money value in it's internal memory. That's when things can get really wrong.
Here you can see an application where iButton is used to store money value for purchasing goods from vending machines. The problem for sellers here is that they used non-secure iButtons, so it is pretty easy to restore it's original credit or money value after being completely spent! All that is required is a simple 1-wire to RS232 converter and a VisualBasic application.
Source: Furrtek
JUL6
Laptop PC robot base update
This is actually an update of previous post regarding the Laptop PC robot base project. Author has updated and somewhat finished this project. The robot, or should we say laptop, is moving around as you can see in the video.
"Here you will see a 3-wheeled base for a robot who's brain is your notebook PC. With this configuration you will not end up without FLASH memory and you pretty much don't have any limitations. You can easily access: wifi, web camera, you can write your own image processing software and don't care how big it is, you can access it with your bluetooth phone and so on."
Source: psymansays
JUL3
Interfacing LED matrix to Arduino
Connecting many LEDs on a microcontroller can sometimes be a real hassle. Here you will see how easy it is to connect 80 LEDs to only 8+2 microcontroller pins.
In this project, decimal counter chip CD4017 is used which is controlled with only two pins: clock and reset. Clock pin will "shift" the ON state of outputs from 1 through 10, while reset pin resets state to first output. This counter is used to address 10 rows on a display, while 8 columns (10x8) are controlled directly from a microcontroller which in this case is Arduino. Outputs of decimal counter are amplified with NPN transistors as seen in the schematics. Source code is available for download on project page.
Source: Syst3mX
JUN29
RFID tag emulation with ATtiny85
Wow, we can finally clone those read-only RFID tags with no trouble at all. This device emulates EM4102 RFID read-only tags that operate on 125kHz.
This project consists of just a few parts, literally, but the way they operate is quite ingenious. The most eye-catching thing is that ATtiny's power pins aren't even connected to power supply. Actually, there is no power supply we can pinpoint here, at all! It is powered from as little as 1V that it gets from reader's "primary" coil. Another crazy thing is that the clock of ATtiny is in sync with reader's frequency (125kHz) because tag's coil is connected directly to microcontroller's clock input pin. Read on to see how interesting things can get...
Source: scanwidget
JUN24
Robot voice modulator
Even though days of phone pranking are pretty much in the past, this device is still worth making. I am talking about a real-time voice modulator that transforms audio input into the famous "robot voice".
Heart of this device is Holtek HT8950 voice modulator which needs only few external components and a power supply to work. Modulator can be built in a hand held box with a battery or as a desk sitting tool as shown in the picture. As the author states, this integrated circuit offers a lot more than the "robot voice", it can shift audio input two whole octaves in either direction which can be accomplished by pushing appropriate buttons. There is even an mp3 file on the project page with a sample of modulated voice. HT8950 can be purchased on eBay and it is very cheap for hours of fun that you will have with this device.
Source: randofo
JUN23
Repair dead pixels on LCD display
There is nothing worse than partially working LCD even if just one pixel is is not working. Although this method can not be applied on LCD monitors and larger panels, it gives great results with those small 7-segment and graphical LCDs.
On any display that doesn't use rubber zebra strip, heat seal connector is probably used. Heat seal connector is a self adhesive tape with conductive lines printed on it. With the help of glue on this tape a contact is made with the glass LCD panel. After some time, this glue dries out and it is necessary to re-activate it by using hot air and applying small amount of pressure. Here you can see a successful attempt of fixing a cordless phone's LCD panel using this method. Instead of using hot air, clothing iron can be used as well as soldering iron with a piece of cardboard on it's tip to distribute the pressure evenly.
Source: blakhatt
JUN18
BristleBot with sensor from optical mouse
About a month ago we have seen those quick and funny solderless robots with no brain that moved only in one direction. Well, this time someone got an idea of smartening them up.
Two vibration motors are mounted on two tooth brush heads and they are controlled with Attiny13 microcontroller. Sensible motor control is accomplished by using a sensor from an optical mouse. Used sensor is ADNS5020 but author notes that it is possible to use other similar sensors. Source code for Attiny13 is written in C and it is available for download. This is very good part of the whole thing, because in it we can find routines for communicating with mentioned optical sensor.
Source: Sprite_tm
JUN16
RGB bike POV
This is a gadget for those who wish to draw attention when riding a bike. We have already seen POV speedometer for bike, but this device will allow you to display images and text in full color.
The device has 16 RGB LEDs which are controller with TLC5940/1 PWM LED controller and Atmega168p/328p microcontroller. Image synchronization is accomplished by using hall effect sensor with appropriate magnet mounted on bicycle's frame. Author warns us that it is very important to properly secure batteries since they can fly away due to wheel's high rotation speed. As this is an "open" project, schematics and microcontroller source code are available for download on project page.
Source: Hazard
