Live Tracking

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Able to use Runkeeper thanks to Three network’s free unlimited data in parts of Europe(France, Switzerland and Italy)!

Runkeeper will post live tracking links on twitter and Facebook everyday if there is data connection.

https://mobile.twitter.com/vitohuang

Runkeeper account

“Live” tracking – require data connection which can be a problem in less developed country and outright expensive, so the idea is to have GPS locations data over SMS text message instead. Keep en eye on this space!

Part 1

An Android app that record GPS location at every X interval (e.g every 30 minutes to save battery), then use SMS text message to send out GPS locations every hour.

Part 2

Use Twilio to receive the SMS text message, Twilio will forward the SMS text message to the server, then the server will save the GPS locations and display it on a map.

* These location is come from an app which use GPS or Cell tower to do the location, so sometimes it think we are in somewhere else, but the general direction should be fine.

Note

A GPS location can be represent in decimal degree e.g Big Ben in London have Latitude of 51.500782 and Longitude of -0.124669 (51.500782,-0.124669), the more decimal points the more accurate, but for this trip two decimal points is good enough (town or village can be identified), since the trip is always on Northern Hemisphere and east from Greenwich, so the latitude and longitude will always be positive number, this means a GPS location will have the maximum length of 7 characters (22.27,114.17). A text message can have maximum 160 characters.

One SMS text can contain 20 locations – 160 / (7 + 1) = 20 (1 is for the separator/delimiter between each coordinate).

Potentially there might be 8/9 hours on the move each day, so sending out a text every hour is a reasonable thing to do.