RFID reader and tag testingThe RFID reader was tested in various ways to determine any issues which may affect the implementation of the final prototype of the project. These experiments tested issues involving; proximity, orientation, movement, and spacing distance. Three different RFID tags were also used in each instance of the testing. The tags ranged from a “button” style tag, a wristband style tag, and a larger credit card sized sticker style tag.
Proximity of the reader was tested, and found that the maximum reading distance between the RFID reader and tag was approximately 6cm. A tag was also able to be read, however, when it was placed on the underside of a desk which showed that some penetration of the radio waves was possible through objects of a considerable thickness.
The RFID readers we wish to purchase, state that they are able to read tags at a distance of up to 3 inches (approximately 7.6cm). However, this will require more testing once they have been purchased to determine their limits.
Orientation of the reader showed that certain tags were not able to be read when the reader was of a suboptimal angle to the tags. This was the case with the button, and wrist-band style tags. The larger tags were far more lenient in terms of orientation, and showed no instances where they couldn’t be read by the reader at any angle.
Movement of the reader during scanning showed that the tags could be read unless the reader was moving relatively fast. Small movements, however, were not a problem for the tag to be identified.
Spacing distance between tags was tested to determine how far between tags is needed for the reader not to detect multiple tags simultaneously (which results in no information being read), or not detect any tag at all. Having only one tag for the button and credit card sized style RFID tags to test, will mean that further testing will have to take place later. For the wrist-band style tags, there were still orientation issues which resulted in reading errors. Also, it was noted that if two tags were situated on top of each other, one of them would be read and not the other. The tag which was read each time seemed to be arbitrary. However the optimal distance between tags was found to be around 4-5cm.
ConclusionsFrom the testing, it was concluded that the RFID option was indeed valid. A large number of tags will be needed, but the concept is one which it technically achievable. The tags which would be most beneficial for the project are the larger credit-card sized sticker style RFID tags. These have the advantage of taking up more space, therefore meaning that less will be needed. There was also no orientation issues found with this type of tag.
