Systems engineering *

I’m going to hazard a guess and say that everyone whose friends or family have ever flown on a plane, have used Flightradar24 — a free and convenient service for tracking flights in real time.



But, if my friends are any indication, very few people know that the service is community-driven and is supported by a group of enthusiasts gathering and sending data. Even fewer people know that anyone can join the project — including you.

Let’s see how Flightradar and similar other services works.

Hi all!

Every person is using barcodes nowadays, mostly without noticing this. When we are buying the groceries in the store, their identifiers are getting from barcodes. Its also the same with goods in the warehouses, postal parcels and so on. But not so many people actually know, how it works.

What is 'inside' the barcode, and what is encoded on this image?



Lets figure it out, and also lets write our own bar decoder.

Long time ago, when a mobile phone costed about 2000$ and one minute of voice call was 50 cents, pagers were really popular. Later cellular phones became cheaper, calls and SMS prices became lower, and finally pagers mostly disappeared.


For people, who owned a pager before, and want to know how it works, this article will be useful.