APRS (Automatic Packet Reporting System) is an amateur-radio based system for realtime communication using digital packets sent over radio links. I present here, an implementation of an APRS iGate using the Raspberry-Pi. An APRS iGate is an Internet gateway that gates packets from the radio/RF side to the  APRS-IS on the Internet (and vice-versa). The APRS-IS is an Internet based network that connects APRS networks from all around the world and facilitates APRS applications (like realtime postion reporting of objects overlaid over google maps, see aprs.fi)

piGate - the complete setup (minus the 2m antenna)

piGate – complete setup (minus the 2m antenna)

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Close-up inspection of a trial. The drag soldering method works quite well.

I am M6JAT

16 Jan
2010

Got my amateur radio foundation license on Wednesday and just bought my new radio.. yipeee.. cant wait to get on air…

Yaesu VX-6R

Yaesu VX-6R

Just finished reading this book. Get a preview of the book on Google Books here before buying it. I bought the low cost Asian edition for  Rs.175 (~$4).  The book starts up well but then loses focus and get disorganized. I feel that the authors should have concentrated more on security aspects related to the interface between the RFID tags and the RFID readers. I say this because  the rest of the system (including the RFID middleware) is like any other computer network and many other good books are available on that topic.

Final verdict: Good if you want to get an overview of RFID technology and security aspects but not recommended otherwise.

Intercity Express on Koln Station
An ICE train on Koln Station

The ICE (Intercity Express) is a system of high speed trains operated by the Deutsche Bahn in Germany and its neighbouring countries.  These high speed trains have top speeds of upto 350km/hr.  During 2007-2008, I ocassionally got a chance to travel onboard these trains. I always got thrilled when the digital displays in the coach showed the train travelling at speeds greater than 300km/hr. One day while travelling from Brussels to Koln onboard an ICE, I was curious about if I could measure the speed of the train somehow.  And then I realized that the solution was in my pocket, my N95 mobile phone. I took it out, started the GPS application and pointed the GPS antenna (below the ’0′ key in the N95) towards the sky from the window, hoping to get a GPS lock-on. I got a lock-on soon enough and there it was, “239.9km/hr” the current speed of the train.

 

Speed of the train measured by the GPS

Speed of the train measured by the GPS

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