Card reader is a simple object that we use in everyday life to swipe into a building or room. It is located on the wall by the entrances of most dorms and academic buildings.
The card reader present is capabilities to the user by flashing a green light when successfully swiped, a red light for default, and a yellow light for not processing. The user can swipe their ID card on the card reader to unlock the door. The affordance of the card reader is to ensure security of accessing the accommodations for students and faculty.
And yet many users give negative feedback of this product because it is hard to tell which side of ID card should be swiped, and hope long should the card stay in the reader for the reader to read the signal of the ID cards.To improve, I suggest painting the side where the card should be facing into a darker color of the card reader, so that users can visually process the instructions.
The power draw of this object is approximately 10 Watts. (Source: https://superuser.com/questions/282202/which-consumes-more-power-hard-drive-or-sd-card-card-reader)
Great product to choose and well done summary of its interfaces.