You may have heard of RFID, but what is it, and why might you want to use it? In a nutshell, RFID is a technology that lets a computer detect any tagged objects nearby. Such a system always has two parts to it: an RFID reader attached to the computer, and a number of RFID tags on objects. The reader uses Radio Frequency communications to read the ID numbers of the tags, hence RFID.
A far cry from Big Brother scenarios, RFID technology has recently become a medium for artists like Meghan Trainor, whose work offers a glimpse of a future in which computers will be able to scan any item and know something about it. [...] “The idea of objects no longer being anonymous — that’s incredible to someone who makes objects,” the New York artist said.
Here at the DMDN lab, we have a number of RFID readers and tags. The readers we use are these ones from Parallax. This reader has a range of about two to four centimetres. We have two types of tags, pictured below. Apart from looking different, they work in exactly the same way.
You can use the reader by plugging it directly into your computer, and when you hold a tag up to it, it reads the unique ID number of the tag, and sends it to the computer. The ID number itself doesn’t provide much information, but it does let us distinguish between the two types of tags. And if we had the tags attached to different objects, we could use the different IDs to find out which object we were detecting.
To demonstrate how this works, I have written an example application in Processing, which you can download here. It listens for an ID number from the reader, and, using this number, figures out which of the two types of tags (round or rectangular) is being picked up. It then displays the silhouette of the appropriate tag type on screen. The two images below show what happens when you hold the two types of tag up to the reader.
