Posts Tagged ‘wireless’

A GPS without GPS

Monday, July 11th, 2011

gsmlocalizerWow, that sounds weird. It’s actually a mini GSM-based localizer without any GPS devices attached. It’s an old device with the cheaper SimCom module SIM900.  Here is a complete working GSM localizator which is pretty cheap and small too.

As introduction, this system allows localization without directly using GPS technology; we are able to locate the desired object fairly precisely by using database availability together with the geographic position of the cells themselves. In some country the cell coordinates are not publicly known (i.e. in Italy). If so, where do we find such data? Through Google Maps… Google has been able to store billions of data regarding the location of its clients’ cell phones. But how does GSM localization work? The radio mobile network is made up of a number of adjacent radio cells, each of which is characterized by an identifier consisting of four data: a progressive number (Cell ID), a code related to the area in which that given cell is (LAC, or Local Area Code), the code of national network to which the cell belongs (MCC, an acronym for  Mobile Country Code), and finally the company code (MNC, or Mobile Network Code), which obviously identifies the phone company itself. For this reason, once a cell name and coordinates are known, and considering the maximum distance allowed between this cell and a phone  before the phone connects to a new cell, it is possible to find out, approximately, the most distant position of the phone itself. For example, if the maximum distance has been determined to be one mile, the cell phone can be within a one-mile radius. It can be deduced that the more cells are found in a given area, the more precisely one can determine where the phone is located (up to 200-350 feet). The idea of employing only a GSM device to build a remote localization system occurred to us when we realized that Google Maps Mobile, which had been conceived to allow smartphones equipped with a GPS receiver to use Google for satellite navigation, was extended to all cell phones, as long as they were able to support GPRS or UMTS data.  Naturally, this method allows but for a rough estimate: determining the precise position of the cell phone hinges on data regarding the coverage of a given cell which can only be provided by the Google server.

DataCell

The circuit

Compared to traditional localizers based on GPS, this device presents many advantages, primarily because it is lighter and less bulky, has a cost lesser and greater autonomy to exercise. This means that about one battery lithium ion, such as 1 Ah, our tracker can be in operation for several days (it all depends on the number of SMS that have to do). A locator based on cellular network may answare more immediately: the GPS receiver may take several minutes to determine its position. Our tracker works battery and thus can be brought on by people who may have the need to ask help or be tracked, but also placed on board motor vehicles (without installation) or simply introduced in goods in transit. To avoid unnecessarily draining the battery, the localizator provides its position via SMS, on requesto with a simple phone call. Among the functions implemented there is the SOS: By pressing the button the localizator sends a text message asking for help, containing the coordinates of position, the sending can be done to a maximum of eight thelephone numbers. When queried or with the autoreport function, sends an SMS with the localization.To know the location of remote device must send an SMS request cell is connected and sends a request (via GPRS) to Google’s site, the latter responds with the coordinates and the figure for the precision. Everything happens in seconds.

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Well, you can get hell of these stuff from link provided afterward. Design files and the firmware are included. A fun stuff to experiment with at your disposal. Mini GSM localizer without GPS at open-electronics.org.

All images are courtesy of open-electronics.org

Wireless explanations

Friday, October 29th, 2010

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Consumers today can choose from WHDI, wireless HD, WiDi, wireless USB and Wi-Fi Direct. Confused? Check out our guide to these emerging wireless streaming-media technologies.

WHDI

Wireless Home Digital Interface, or WHDI, was finalized in 2009 to give consumers a way to link the PC to the TV. Think of it as the wireless equivalent of HDMI. The technology has a latency of less than 1 millisecond, which means it’s good enough not just for watching movies but should also work well to stream games from your browser to the TV.

WHDI can stream 1080p video at up to 3 Gbps (gigabits per second). All you need is a wireless HDI dongle that can plug into your laptop and a little receiver that goes behind the TV. That set will cost about RM464.48 and will be available early next year.

Meanwhile, TV makers such as Sharp and LG are rolling out TVs with built-in support for WHDI standard.

Slowly, the WHDI consortium hopes to convince PC makers integrate WHDI chips into laptops, similar to the way Wi-Fi chips are built in today.

WirelessHD

While other wireless technologies focus on streaming content from the PC to the TV, WirelessHD targets the most common electronic eyesore in homes: the black HDMI cables that snake out from behind the TV towards the set-top box, PC or the DVD player.

If built into TV sets, WirelessHD can offer fast data transfers of up to 10 GBps to 28 Gbps. That makes it the fastest of the lot for point-to-point data transfer.

So far, TV makers such as Panasonic, LG and Vizio have said they will offer wireless-HD–enabled sets by the end of the year. (more…)

Brilliant SCADA System that failed

Sunday, September 19th, 2010

A friend of mine shared an article about software failures. it’s a good stuff to read, where we can avoid some mistakes that previously been made by software developers. there is a SCADA software there – some of the problems that I’ve been encountered too in my life. check this out:

http://images.nakedmaya.com/Troll-Link1-sm.jpgNet-Herald – a monitoring application for water supply companies. It was a complex client server application that would receive monitoring data from specialized hardware and store that data inside a SQL database. The client displays that data in different graphs, provides printable reports or sends alarm messages via SMS if a monitored value is not within its specified limits. I developed Net-Herald as a perfect fit for that specialized hardware that is provided by a local manufacturer. That way, so I hoped, I could profit from their sales leads and would find a smoother way into these water supply companies. The downside of course, was that my software would only work with their hardware. (more…)

How to decode infrared transmission

Thursday, April 22nd, 2010

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Alright, here we’re going for chapter on Manchester Encoding. Brian J Hoskins did just that when building this RC5 decoder. This protocol is widely used in television remote controls. You use them on a daily basis, don’t you think it’s time you understood what’s going on? Check out his writeup and learn the dark art of invisible light communication. Or just skip the learning and follow this how-to.

courtesy: Hack a day

Python IR tracking for the handicapped

Tuesday, March 2nd, 2010

[Techb] had a friend who was paralyzed after an accident and could no long use a computer. He rigged up an amazingly simple mouse interface using python to implement infrared tracking. The controller was built from an old hat by adding an IR LED and wireless mouse modified so that the button could be clicked by the user’s mouth. A webcam with exposed film used as a filter can track the IR LED and take input from the wireless mouse buttons.

This setup, which draws inspiration from Wii Remote white boards,  is much simpler than the Eyewriter (and doesn’t shine an IR LED into your eye). Although [Techb] wants to add facial recognition to the system, there’s something to be said for such a simple implementation.

courtesy hackaday

RFID tracking system

Wednesday, February 24th, 2010

This is a working tracking system using RFID tags built by Nicholas Skinner. The system’s tags operate in the 2.4 GHz band and are used to track either people or assets. The readers are on a mesh network and can triangulate the location of any tag for display on a map. His system is even set up to show the travel history of each tag. [Nicholas] shared every detail in his writeup including some background about available hardware options and how he made his final decisions on what devices to use for the job. His conglomeration of software that ties the whole project together is also available for download.

http://hackadaycom.files.wordpress.com/2010/02/rfid-tracking-system.jpg?w=470&h=344

courtesy: ns-tech

Wireless and real-time health tracker

Tuesday, January 19th, 2010

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A company calling its collective group of body monitoring products the WIN Human Recorder system has released a new device called the HRS-I. Designed to measure and record a person’s electrocardiographic signals, body surface temperature and overall body movements, the tiny unit can easily be worn under your shirt as you attend to your daily business.

The device communicates wirelessly with a remote base and can last on a single charge for up to three days. Targeted toward companies working to monitor employee health, the HRS-I can be purchased for just 30,000 yen ($331) and the monitoring service costs just 10,000 yen ($110) per month.

Via Nikkei

RCA Wifi power harvester

Wednesday, January 13th, 2010

You can now harvest WiFi signals and turn it into power to charger up your mobile phone or netbooks.

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This little box has, inside it, some kind of circuitry that harvests WiFi energy out of the air and converts it into electricity. This has been done before, but the Airnergy is able to harvest electricity with a high enough efficiency to make it practically useful: on the CES floor, they were able to charge a BlackBerry from 30% to full in about 90 minutes, using nothing but ambient WiFi signals as a power source.


Source: Oh!Gizmo

RFID emulator

Wednesday, January 6th, 2010

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[Alexander] built an RFID emulator. It uses a wire coil (not pictured here) and an ATmega8 to represent any tag that is EM4001 compliant. This iteration requires connection to a computer to send the tag ID information to the microcontroller. In the video after the break it looks like he’s using a DIY RFID reader to test this. If the two were combined, cutting out the need for a computer, he would have an RFID spoofer on his hands.

source: hackaday

Sony’s wireless electricity offering

Sunday, October 4th, 2009

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In August hackaday covered a wireless electricity presentation from the TED conference. Now Sony has put out a press release on their wireless flat panel television prototype. The device is capable of operating without audio, video, or power cables connected to it. This is possible at distances up to 50cm at efficiencies as high as 80%.

As was talked about in the comments of the other article, the efficiency compared to that of a cable doesn’t blow our socks off. But this does show mainstream development of this technology. We hope to see advances in both efficiency and distance. We also look forward to that small black box (which we presume facilitates the energy transfer) being integrated into the TV’s body.

source: gizmodo via hackaday