Do you know how barcodes and barcode scanners work?

We often see barcodes being used in almost all the items we buy in a Supermart. These Black – and – White zebra stripes are seen on in every item from shampoo to Electronics like TV’s and Refrigerators.

What are barcodes used for?

If you own a store, you need to store details of various items so that the best sellers are always in stock. The easiest way to solve the problem is to walk around the shelves looking for empty spaces and refilling the necessary ones. Or, you could write down the list of items which people buy at the checkout and then using those details you can reorder the stuff needed. This method works for small stores, but what about the huge stores like Wal-Mart with millions of items sold everyday? There are so many other difficulties of running shops smoothly with such huge sales. Marking all your items with their prices works but you need to change the prices before selling the goods and you have to reprice everything. And we can’t even be sure that items missing from the shelves are certainly sold. How will we know if some items have been stolen?

Usage of barcode technology in stores helps to solve all these problems. This technology lets you keep a centralized record on a computer system that tracks prices, products and stock levels. We can change prices as often as we like, without having worry about new price tags. We can instantly see when stock levels of some items are running low and we can reorder.

A barcode-based stock system like the one mentioned above consists of three main parts. First, there’s a central computer which runs a database that keeps stores the data of all your sales, what each one costs, who makes it and how many you have in stock. Second part is the barcodes printed on all the products. Finally, there’s one or more checkout scanners that can read the barcodes.

How barcodes represent the numbers 0-9

The idea of barcode is really simple : every item that you want to classify is given an own and unique number, then simply print the number on the item so a barcode scanner can read it. We could print the number itself, but the problem with decimal numbers is that they are easy to get confused like a misprinted eight could look like a three to a computer and six is identical to nine if you turn it upside down.

Looking at a barcode, you probably can’t make tail or head of it: you don’t know where one number begins and another one ends. But it’s very simple . Each digit in the product number is given the same amount of horizontal space which is exactly 7 units. Then, to represent any number from zero through nine, we simply color the seven units with a different pattern of black and white stripes. This is how, the number one is represented by coloring in two white stripes, two black stripes, two white stripes, and one black stripe, while the number two is represented by two white stripes, one black stripe, two white stripes, and two final black stripes.

Probably you have noticed that barcodes can be quite long and which is because they are supposed to represent three different kinds of information. The first part of a barcode tells you the country where it was issued. The next part reveals the manufacturer of the product. The final part of the barcode identifies the product itself. Different types of the same basic product (for example, four-packs of Coca-Cola bottles and six-packs of Coca-Cola cans) have totally different barcode numbers.

Most products use a simple barcode called the UPC (universal product code)—a line of vertical stripes with a numbers printed underneath it. There is another kind of barcode that is becoming increasingly common and its stores much more information. It’s called a 2D (two-dimensional) barcode) and you sometimes see it on things like self-printed postage stamps.

Source: CodingSec