The Zap is a solar powered, wifi internet enabled RFID reader (now that is a mouthful). Sounds complicated, but it’s not so bad if you look at it piece by piece:
- On the top is a solar panel. The solar panel converts sunlight into electricity, and keeps the Zap’s battery charged up.
- In the middle is a control box. The battery is in there, along with a bunch of electronics that makes the whole thing work - think of it like a specialized computer. Also on the outside of the control box is a green light and a speaker.
- At the bottom is the RFID antenna. The angle of the RFID antenna can be adjusted to create the desired "field of vision" for the system.
- On some systems, up top is a wifi antenna that lets the Zap talk to the school wifi network and get on the internet to transfer its data to our web site database.
So those are the basic parts - here is how it works:
First of all, the system pretty much takes care of itself - it watches its battery level, and monitors the network connection, stuff like that - and it tells our web site if anything bad happens. The system powers the RFID antenna, which creates a "field of vision" in front of the antenna.
When a RFID tag enters the field, the Zap reads the unique number encoded in the tag, and records it in its memory. It also flashes the light and makes a sound so that the owner of the tag knows that his tag was recorded. This feedback is important because the machine has to get a good "look" at the tag - it can’t see through stuff too well, so the kids need to be sure they don’t block the Zap’s vision. After a while they learn how to do the "Zap Wiggle," which gets the tag oriented so the machine can read it.
The Zap will only beep for a particular tag once every 15 minutes - which helps the kids to be sure that the beep they heard was for their tag (if 3 kids walk past together, as long as they hear 3 beeps, they will know they were all counted). If someone goes past the Zap more than once during the day, the system only records one trip for them. And if for some reason, someone has more than one tag registered to them, and both tags are read, the system still only records one trip. If someone can’t get their tag to ring, or forgets to go past the Zap, their parents can go on the web site and add a trip for them.
About every 15 minutes, the Zap will automatically contact our web site and transfer its data. If it can’t get through for some reason, it just tries again later. It can remember many days worth of trips if necessary. Of course, the trips won’t show up on the web site until the Zap connects.