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 – complete setup (minus the 2m antenna)
- In: Uncategorized
Hand soldering a quad flat pack device
19 Aug2011
Close-up inspection of a trial. The drag soldering method works quite well.
- In: Uncategorized
I am M6JAT
16 Jan2010
Got my amateur radio foundation license on Wednesday and just bought my new radio.. yipeee.. cant wait to get on air…
Yaesu VX-6R
- In: Amateur Radio|Hobbies
Book Review: RFID Security, Syngress Press
13 Sep2009
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.
- In: Books
- 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
- In: Experiments|Travel