Interface Up To 12 Servos Using Arduino

November 24, 2010 by Mike Szczys 5 Comments

[Brian] is using an Arduino to control multiple servo motors. This is nothing new and has been happening since the earliest days of Arduino. But rather than develop a project and share it, [Brian] did a fantastic job of making the code scalable, readable, and even explained how the different parts work.

His code listens for serial commands and manipulates the motors accordingly. He wrote a Python script using pyserial which talks to the Arduino. As an example, he uses a joystick to send data for X and Y axes as well as pitch and roll. Want to know how those serial communications work? He explains that in detail. He also outlines the process of scaling up from the 4 servo demo to 12 servos on a standard Arduino. Sounds like it might be time to build your own version of a mouse-controlled Lynxmotion arm using the tools [Brian] has put together.

Communicating With An LED Matrix

November 19, 2010 by Mike Szczys 9 Comments

Most of the LED matrix posts we run delve into the hardware design. This time around [J Bremnant] used prefab modules and focused on writing code to address the display. The hardware combines two 24×16 LED boards from Sure Electronics with a Teensy 2.0 to drive the display and provide a USB connection. The firmware comes in just under 8k, leaving graphic manipulation up to a PC.

[J Bremnant’s] Python script offers a lot of flexibility when working with the display. There are three modes selectable through a terminal interface. One just tests the display and then drops into Conway’s Game of Life. The second mode lets you send commands via serial interface so it can be used as a message ticker. The final feature is frame addressing that allows graphics to be dropped into the display. See each of these featured in the video after the break.

Continue reading “Communicating With An LED Matrix” →

Android Oscilloscope

October 14, 2010 by Mike Szczys 31 Comments

Here’s a 2-channel Oscilloscope for your Android phone. It uses a base module driven by a dsPIC for signal processing. From there, an LMX9838 Bluetooth module broadcasts the data to the phone so that the waveform can be displayed. [Yus] ported some Python code he had been using over to a set of Java and XML files in order to get it working on Android. This was actually the first time he worked with the SDK… we’d say he’s a quick learner. See it in action after the break.

Continue reading “Android Oscilloscope” →

BIOS Password Cracking

October 7, 2010 by Mike Szczys 45 Comments

[Dogbert] took a look at the security that goes into BIOS passwords on many laptops. He starts off with a little background about how the systems work. People are bound to forget their passwords, so when you enter a wrong one three times in a row you get a message similar to the one above that locks you out until all power is removed from the system (then you get three more tries). But check out that five-digit number in the picture. That’s a checksum of the password. Some BIOS versions display it automatically, some require you to hold down a certain key during POST, but it’s the pivotal data needed to crack the password.

[Dogbert’s] post doesn’t go into verbose detail about the algorithms he uses to brute force the passwords. But he has posted the Python scripts he uses to do so. Learning how to generate the passwords based on the checksum is as simple as studying the code, which is often the best way to learn.

Arduino, RFID, And You

October 7, 2010 by Jakob Griffith 13 Comments

[Matt] has mixed up a batch of two RFID reading door lock systems. While the “door lock” part of the setup has yet to come into existence, the “RFID reading” section is up and running. By using the Parallax RFID readers (for cheap, remember?) and an Arduino, [Matt] is able to parse an RFID tag, look its number up in a database, and then have a computer announce “Access Denied” in a creamy “Douglas Adam’s sliding door of Hitchiker’s Guide” kind of way with Python.

Good books aside, catch a not as exciting as you’re thinking video after the jump.

Continue reading “Arduino, RFID, And You” →

Decoding MP3 In Python

October 2, 2010 by Mike Szczys 32 Comments

We all listen to them, but do you know how the compression for an MP3 file actually works? [Portalfire] wanted to find out, while honing his Python skills at the same time. He’s been working on an MP3 decoder in the Python language. So far he’s had some success, with the first working decoder clocking in at just 34 times slower than real-time. But since then a bit of optimization improved that to 10 times slower.

Sure, it’s not a usable module yet but his goal of learning the algorithms has been reached. A combination of reading about the standard and looking at code from other projects made that possible. In the future he plans to try the same thing with the H.264 codec.

Python Library For Emotiv EEG

September 13, 2010 by Mike Szczys 23 Comments

Want to control things with your mind? The Emotiv EPOCH EEG is one of the best pieces of hardware you can get that is ready to be hacked into your project. Too bad the entry-level SDK will set you back $500. Or you can take advantage of [Cody Brocious’] work by using his Emotiv Python Library. He sniffed around the data coming in over the USB connection and discovered that it’s encrypted. With a bit of trickery he extracted the key and built the 128-aes decryption routine into his package. So far this just pulls raw data from the unit so it’s up to you to figure out how to properly filter the signals and differentiate which sensor corresponds to each data stream. But it’s a start, and hopefully it’ll lead to more mind controlled doo-dads.