Super Game Boy Boot ROM Dumped

September 18, 2009 by Mike Szczys 31 Comments

gameboy_boot_rom_dump_hardware

[Costis] managed to dump a copy of the boot ROM for the Nintendo Super Game Boy. This small piece of code (256 bytes) writes a graphic to the display at boot time as it loads the ROM on the game cartridge. He was able to dump the code by finding the exact point at which the device locks down the boot ROM. Just as that point approached he overclocked the device causing it operate so fast it couldn’t write the lockout bits into the register. Once past that single point of security, he executes a code that writes the boot rom out to a different address that he is able to read from. He’s got a copy of the dump along with the explanation up for your enjoyment.

[Thanks Anthony]

How To Write Udev Rules

September 18, 2009 by Mike Szczys 36 Comments

Since the adoption of Kernel 2.6, Linux has used the udev system to handle devices such as USB connected peripherals. If you want to change the behavior when you plug something into a USB port, this section is for you. As an example, we will use a USB thumb drive but these methods should translate to any device handled by udev. As a goal for this exercise we decided to create a symlink and execute a script when a specific thumb drive was loaded. The operating system we used for this exercise is Ubuntu 9.04 Jaunty Jackalope. Continue reading “How To Write Udev Rules” →

Touch Sensitive Keypad

September 18, 2009 by Mike Szczys 12 Comments

capacitive_keypad

[Viacheslav] built a keypad that uses human capacitance to detect key presses. Unlike normal keys which close a physical connection, his project detects touch through the PCB substrate. He uses the analog comparator of an AVR ATmega8 to detect the moment of zero crossing and then measures the time it takes to discharge in order to detect key presses.

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Software Pulse Width Modulation

September 17, 2009 by Mike Szczys 11 Comments

daqq_pwm_schematic

Pulse Width Modulation is a topic that tends to give a lot of beginners trouble. [Daqq], whose nixie plasma ball we covered a few days ago, has a simple but effective PWM project that you should take a look at. The circuit used 9 LEDs clustered together into 3 sets of RGB modules and connected them to an AVR ATtiny2313 through some current limiting resistors. Most of the time the PWM function of the AVR’s timers would be used to generate the signal but this application calls for 9 signals which is more than can be produced by this chip. The workaround is to generate the signals using software PWM. Continue reading “Software Pulse Width Modulation” →

Build Your Own Joystick

September 17, 2009 by Mike Szczys 38 Comments

macgyver_joystick

What can you build with a ballpoint pen and some extra parts? [gzip] found himself with a bonus box of right angle switches and other miscellaneous parts and set out to build a joystick. Simple arcade joysticks use switches that are actuated by the movement of the stick and this design embraces the concept. The four tactile switches are mounted on protoboard facing each other with part of a ballpoint pen in the middle. When the pen is moved it presses against one or more switches to close, completing a circuit. For good measure he even incorporated a fire button into the top of the “stick”. Now we just need someone to make this work with a tiny Ms. Pac-Man emulator.

IPhone Cop-cam

September 17, 2009 by Mike Szczys 46 Comments

iphone_windshield_mount

[Tim] wanted to make some recordings of himself driving similar to those made by the dashboard cameras on police cars. In a simple two step hack (1. Measure, 2. Drill), he altered his iPhone windshield mount so that it didn’t block the lens of the camera. We will admit (sheepishly) that at first glance we thought this might be connected to the outside of the windshield but it’s not. Take a look at his drive to work after the break.

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How To Replace A Netgear Router Antenna

September 16, 2009 by Mike Szczys 65 Comments

rp-sma-adapter-installed

a.ntivir.us wanted to use a different antenna for their Netgear mbr624gu WiFi router. Unfortunately, this model comes with an antenna that is not removable. As with other antenna retrofits, this involves no soldering. But because there is already a mounting area for an antenna, no case altering is needed either. After opening the router with a Torx driver it was discovered that the non-removable antenna was connected to the board with a mini rf connector (U.FL). The antenna and its mounting bracket were removed and a U.FL to RP-SMA adapter was put in its place using a washer to secure it to the rear plate of the router. Now any external antenna can be used and the router still looks brand new.