Tool Tip: Microcontroller Timer Calculator

September 28, 2009 by Mike Szczys 11 Comments

uC_timer_calculator

In life and embedded systems timing is everything. Give [Frank’s] web-based timer calculator a try. Set your system clock resolution (in hertz making sure you account for any system clock divider), select your timer resolution and prescaler, then calculate based on desired ticks, overflows, or real time. He’s built this with the AVR chips in mind but it should be handy for any family of microcontrollers.

Of course none of this is rocket science, but if you’re trying to use one timer for two differently synchronized events this can save you a lot of trial and error time.

AVR Dragon Wiring Alternative

September 26, 2009 by Mike Szczys 23 Comments

dragon_jumper_board

We love our AVR Dragon programmer. It is a small board with a lot of functionality: in-circuit serial programming, JTAG, debug wire, and high voltage serial programming. Unfortunately, out of the box it is not quite ready for action. The Dragon ships with an unpopulated prototyping area and missing a pin header for the HVSP. For most people this means soldering on pin headers and a ZIF socket then jumpering between the various programming headers and the header for the socket. Tired of working with jumper wires, [Jussi] designed a small PCB to make the connections (original link in Finnish). Continue reading “AVR Dragon Wiring Alternative” →

Steal The Administrator Password From An EEPROM

September 24, 2009 by Mike Szczys 43 Comments

locating_atmel

Did you forget your hardware-based password and now you’re locked out? If it’s an IBM ThinkPad you may be in luck but it involves a bit more than just removing the backup battery. SoDoItYourself has an article detailing the retrieval of password data from an EEPROM.

The process is a fun one. Disassemble your laptop. Build a serial interface and solder it to the EEPROM chip where the password is stored. Connect this interface to a second computer and use it to dump the data into a file. Download a special program to decipher the dump file and dig through the hex code looking for something that resembles the password. Reassemble your laptop and hope that it worked.

We know that most people won’t be in a position to need a ThinkPad administrator password, but there must be other situations in which reading data off of an EEPROM comes in handy. What have you used this method for?

Universal Credit Card In The Palm Of Your Hand

September 23, 2009 by Mike Szczys 38 Comments

universal_credit_card

Do you remember the magnetic card spoofer in Terminator 2? It was a bit farfetched because apparently the device could be swiped through a reader and magically come up with working account numbers and pin numbers. We’re getting close to that kind of magic with [Jaroslaw’s] card spoofer that is button-programmable.

Building off of a project that allows spoofing via an iPod and electromagnet, [Jaroslaw] wanted something that doesn’t require a computer to put together the card code. He accomplished this by interfacing a 16-button keyboard and a character LCD with an AVR ATmega168 microcontroller. Card codes can be entered with the buttons and verified on the LCD. Of course this is still dependent on you knowing the code in the first place.

As you know, credit cards use this technology. We don’t think Walmart is going to be OK with you pulling this out in the checkout line, not to mention local five-oh. This technology is also used for building access in Universities, businesses, and hotels. If used in conjunction with some other spy technology you’ll be on your way to becoming a secret-agent-man.

Wireless RGB Light Bulb

September 20, 2009 by Jake W 15 Comments

Want to make the above yourself? [Sprite_tm] did a thorough job documenting the build step by step (complete with pics, schematics, graphs, and links to the parts used). In summary, [Sprite_tm] busted open an Ikea CFL bulb to reuse the housing. Inside, he installed a scavenged power supply, ATtiny44, RGB LED module, and a radio receiver. A remote control allows [Sprite_tm] to change the lighting of his room to nearly any color. The cost of the project is a little under $30. The price tag isn’t so steep when one considers the insanely long lifetime of LEDs.

Web Controlled Dark Crystal

September 19, 2009 by Mike Szczys 11 Comments

mood_rock_using_shiftbrights

[Reza] sent in his mood rock. Unlike other “mood” devices, instead of showing what mood you’re in, it shows what mood the internets are in. Two ShiftBrite modules are controlled by an AVR ATmega8 which then connects to a computer via USB. The assembly is placed inside of a piece of alabaster.

USB communications are controlled by the ATmega8 running V-USB (formerly AVR-USB) firmware. [Reza] wrote some code to control the colors from the web using Perl and AJAX. Head over to the web interface to set the colors yourself. We’d love it if a live webcam was added so we could see our mood on the rock itself. Continue reading “Web Controlled Dark Crystal” →

EDuino – Arduino Or AVR Breakout?

September 19, 2009 by Mike Szczys 42 Comments

eduino-b_na_breadboard

We’ve had a lot of requests in the comments for more Arduino centered posts so we were happy when [Njay] told us about his EDuino board. This is a minimal Arduino clone that has a crystal and its capacitors, a pull-up resistor and button on the reset pin, and a detachable serial programming connection. He also has a breadboard-friendly version seen above with all the interface pins on one side of the board. This is certainly a useful project and we’re glad to see the board files available for download. This does get us thinking… is this an Arduino, or is it an AVR ATmega168 breakoutboard that happens to use the Arduino boot loader and programming language?