It seems like every Hackerspace should have some type of kludged together access system on their entry door. [Vasilis] wrote in to share the system called Jarvis that controls access to P-Space, a Hackerspace in Patras, Greece. It’s an RFID-based system that offers a few nice features.
They already have a server running the webpage, so basing their entry system off of a computer was an easy option. You can get in one of two ways; by presenting your valid RFID tag to a reader at the front door, or by ringing the bell and having a member inside press the Big Button of Doom (BBoD) which is a wireless controller.
The BBoD has an Xbee module inside which lets it send an unlock command back to the computer. The remote is powered by two AA batteries, and since it’s never on unless the button is pressed the team estimates these batteries should last around one year.
There’s even a feedback system. The computer posts the last few events to the webpage. So you can go online and see when the BBoD was used, or who’s tag has recently unlocked the entrance to tell if your friends are there.
[Dan McGrath] tipped us off about a solution for a problem that most people don’t have. He built a web-based entry system for his garden gate. This isn’t quite as original as that chain and sprocket dorm room system, but it does use a keypad for entry. [Dan’s] already got a web server and home automation box that is always running. He coded a webpage that presents a virtual keypad for code entry. If the right code is input the system unlocks the electronic strike on the other side of this gate. Since the interface is a web page you can load if from any web browser (an iPhone is used for demonstration purposes after the break). But if you don’t have internet access you’re in trouble; there’s no physical keypad. But we guess you could always just jump the fence. Continue reading “Automated entry for a garden gate”
[Fileark] built an RFID entry system that uses a pretty ingenious alternative to an electronic strike plate. An electronic strike is a rather expensive hinged plate that mounts in the door frame and catches the door latch. But this system opens a set of double doors. The door without the handle is fixed in place and has a normal strike plate. But it also has a deadbolt mounted in line with that plate. When the deadbolt is extended it is flush with the strike plate, pushing the latch from the door knob back and freeing the door to swing open. This is a bit hard to put into words so watch the video after the break to clear things up.
The system uses a cheap RFID package that provides a single signal line. This line connects to an old VCR motor which turns the deadbolt. Timing is provided by a 555 chip, and the deadbolt movement is limited by a couple of switches mounted along with the motor.
Now that the unlocking mechanism has been built it would be simple to use other authentication methods for unlocking the door, like a wristwatch-based proximity system.
Continue reading “RFID entry uses homemade electronic strike”