Earthquake Alert System

March 2, 2011 by Mike Szczys 15 Comments

[Roteno’s] submission for the 555 timer design contest is an Internet connected earthquake alert system. It monitors the USGS website for earthquake data and plays a tune when an earthquake occurs. The data is available as a feed in the form of a TXT file which is pretty easy to parse using cURL. He chose an LPCXpresso board (which is an ARM development platform that can run a Linux kernel) along with an XPORT module to handle the Ethernet traffic.

So where does the 555 timer see some action? It is responsible for playing the tone when an earthquake is detected. But playing just one pitch isn’t much fun. Instead, [Roteno] built the circuit above which creates a resistor network switched by a series of transistors. This way he can use GPIO from the microcontroller to choose different pitches. Check out the video after the break to hear the results. At power-up all eight pitches are played as a test, and the alert sound varies in pitch and tempo based on the magnitude of the earthquake.

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Have A Face For Radio?

February 2, 2011 by Jake W 19 Comments

The help of fellow members of the Austrian technology collective/hackerspace [Otelo] allowed [Georg] to develop a networked audio streaming board, with less than $20 worth of components. Dubbed the OggStreamer for obvious reason, it’s designed to relay audio from a mixing board to an Icecast server (an open source implementation of SHOUTcast) in real-time. The board is based on the STM8 Discovery kit and the Xport Pro. It features stereo input, an onboard OGG Vorbis encoder, and (to top it off) is running uClinux. We think it’s very well thought out – but don’t take our word for it… the OggStreamer won second place last year in the Lantronix XPort Pro Design Contest, and [Georg] has documented it extensively (pdf).

Ego Box Monitors Web Hits

January 29, 2011 by Mike Szczys 12 Comments

[Bogdan’s] latest project is a box that displays web hits for a chosen site. He calls it the Ego Box because depending on how traffic goes it either bloats or crushes your ego. This provides similar functionality as our Troll Sniffing Rat but the biggest difference is that this is a stand-alone Ethernet device. That’s thanks to the ENC28J60 Ethernet controller chip which manages the stack and has been quite popular in DIY electronic projects. In order to monitor your hits [Bogdan] crafted a bit of code to add to the header of your index page. It increments the counter file each time the page is loaded, and the Ego Box simply monitors that file, displaying the traffic on an eight digit 7 segment display.

[via Adafruit]

Adding A Serial Port Through An RJ45 Connector

December 30, 2010 by Mike Szczys 21 Comments

[Mike Lu] likes to add serial ports to his routers to use for debugging but he didn’t want to drill holes in his new RT-N12. After a bit of head-scratching he thought about repurposing the four unused wires on one of the RJ45 Ethernet connectors. This would allow him to interface with the necessary signals and still have the option of using that port for a network connection. The first step was to build the circuit to output the correct serial levels and connect it to the unused pins on the jack. Next, to separate serial and Ethernet on the outside of the router he build a short adapter cable.

This is an elegant solution if you’re looking for zero case modifications. But if you don’t mind a few inconspicuous holes we love the serial port used on this Dockstar.

Ethernet Connection Using Capacitive Coupling

October 26, 2010 by Mike Szczys 26 Comments

Wanting to save space and weight on his project build [Florin] set out to find a way to add Ethernet connectivity without the magnetics. His ill-advised first try involved directly coupling two switches, frying both in the process. After some research he found that Ethernet hardware manufacturers have considered the need for devices without the magnetics and there are several application notes available on the subject. [Florin] followed the information that Realtek has for their devices and learned that they can be couple capacitively. After depopulating the magnetics from a second pair of switches he wired up some resistor-capacitor networks on a breadboard and got the connecting to work.

Web Controlled Sprinkler Automation

September 16, 2010 by Mike Szczys 19 Comments

[Doug] needed to update his watering system to comply with his city’s new water saving ordinance. The old system wasn’t capable of being programmed to water only on even or odd calendar days. Rather than purchase a replacement he decided to build his own sprinkler controller. It needed to switch 12V solenoids, a job that’s not too hard to design for. Rather than re-invent the wheel, he modified a previous controller design. It is basically an Arduino and Ethernet shield on a his own etched board. In addition to the ATmega328 and an ENC28J60 (for ethernet connectivity) there is a bank of transistors to drive the watering solenoids. Now he has a web interface that controls the watering schedule and is fully in compliance with the new city code.

If you need another way to save when watering your grass you should take a look at the sidewalk-avoiding sprinkler.

RS232 And RS485 Networking – No Code Required

August 14, 2010 by Mike Szczys 21 Comments

Here’s a serial to Ethernet module that you won’t have to write firmware to build. It uses a Lantronix XPORT module which takes care of all the work for you, including an embedded webserver. Both RS232 and RS485 data buses are connected to the XPORT serial input via a level converter to step the signal down to 3.3V. This solution comes at a price because of the ethernet module, but it would make a nice prototyping tool for testing projects that work on the two serial protocols.