[Shawn] recently overhauled his access control by fitting the doors with some RFID readers. Though the building already had electronic switches in place, unlocking the doors required mashing an aging keypad or pestering someone in an adjacent office to press a button to unlock them for you. [Shawn] tapped into that system by running some wires up into the attic and connecting them to one of two control boxes, each with an ATMega328 inside. Everything functions as you would expect: presenting the right RFID card to the wall-mounted reader sends a signal to the microcontroller, which clicks an accompanying relay that drives the locks.
You may recall [Shawn’s] RFID phone tag hack from last month; the addition of the readers is the second act of the project. If you’re looking to recreate this build, you shouldn’t have any trouble sourcing the same Parallax readers or building out your own Arduino on a stick, either. Check out a quick walkthrough video after the jump.
Continue reading “Quick and Dirty RFID Door Locks Clean up Nice”
[Jason] really wanted to build an RFID controlled garage door opener and decided to turn to Arduino to get the job done. For someone who’s never worked with an Arduino before, he really seemed to know what he was doing.
The Arduino acts as the brains of the operation while an off-the-shelf NFC/RFID reader module is used to read the RFID tags. To add new keys to the system, [Jason] simply swipes his “master” RFID key. An indicator LED lights up and a piezo speaker beeps, letting you know that the system is ready to read a new key. Once the new key is read, the address is stored on an EEPROM. From that point forward the new key is permitted to activate the system.
Whenever a valid key is swiped, the Arduino triggers a relay which can then be used to control just about anything. In this case, [Jason] plans to use it to control his garage door. The system also has a few manual controls. First is the reset button. If this button is held down for two seconds, all of the keys from the EEPROM are erased. This button would obviously only be available to people who are already inside the garage. There is also a DIP switch that allows the user to select how long the relay circuit should remain open. This is configurable in increments of 100ms.
For now the circuit is wired up on a couple of breadboards, but it might be a good idea to use something more permanent. [Jason] could always take it a step further and learn to etch his own PCB’s. Or he could even design a board in Eagle CAD and order a real printed board. Don’t miss the video description of the RFID system below. Continue reading “Upgrade Your Garage Door with Arduino and RFID”
[Mário] sent us a tip detailing the access control system he and his friends built for the eLab Hackerspace in Faro, Portugal. The space is located in the University of Algarve’s Institute of Engineering, which meant the group couldn’t exactly bore some holes through campus property and needed a clever solution to provide 24/7 access to members.
[Mário] quickly ruled out more advanced Bluetooth or NFC options, because he didn’t want to leave out members who did not have a smartphone. Instead, after rummaging around in some junk boxes, the gang settled on hacking an old Siemens C55 phone to serve as a GSM modem and to receive calls from members. The incoming numbers are then compared against a list on the EEPROM of an attached PIC16F88 microcontroller, which directs a motor salvaged from a tobacco vending machine to open the push bar on the front door. They had to set up the motor to move an arm in a motion similar to that of a piston, thus providing the right leverage to both unlock and reset the bar’s position.
Check out [Mário’s] blog for more details and information on how they upload a log of callers to Google spreadsheets, and stick around for a quick video demonstration below. If you’d prefer a more step by step guide to the build, head over to the accompanying Instructables page. Just be careful if you try to reproduce this hack with the Arduino GSM shield.
Continue reading “Open your Hackerspace Door with a Phone Call”
Near Field Communication (NFC) enabled devices are starting to appear in our everyday lives. Shown in the picture above is the xNT (fundraiser warning), a 2mm x 12mm fully NFC Type 2 compliant 13.56MHz RFID tag encased in a cylindrical Schott 8625 bioglass ampule. It was created by [Amal Graafstra], who therefore aims to produce the world’s first NFC compliant RFID implant. The chip used is the NTAG203, which is (for the sake of simplicity) a 144bytes EEPROM with different protection features.
We can only start thinking of the different possibilities this chip will create in the near future, but also wonder which precedent this may set for future NFC enabled humans. Embedded after the break is the presentation video of xNT but also an interview I conducted with [Amal Graafstra], who has already been living for 8 years with RFID tags in each hand.
Continue reading “Hackaday Interview with Amal Graafstra, Creator of xNT Implant Chip”
Let’s rollback the hobby electronics calendar a few decades with [myvideoisonutube’s] alarm activation control circuit using a matrix style phone keypad. The circuit is quite old using CMOS 4081 with 4 ‘AND’ gates to hardwire the access code. [myvideoisonutube] references [Ron’s] “Enhanced 5-Digit Alarm Keypad” schematic for this build changing the recommend keypad with a more common matrix style keypad found in touch pad phones. These types of matrix keypads wouldn’t work outright for the input so he cut some traces and added hookup wires to transform it into a keypad with common terminals and separately connected keys. We love seeing such hacked donor hardware even when it requires extensive modifications. [Ron’s] source circuit included a simple enough to build tactical button keypad if you can’t find a suitable donor phone.
Learning how to use mostly discrete components instead of a microcontroller would be the core objective to build this circuit outside of needing a key-code access point or other secure 12 V relay activated device. Such a device would be quite secure requiring a 4 digit “on” code and 5 digits for “off”. You couldn’t just pull off the keypad and hotwire or short something to gain access either. The 4 digit on “feature” does knock the security down quite a lot. However, all keys not in the access code are connected to the same point so you could increase your security by using a pad with more keys.
On [Ron’s] site you will find a detailed construction guide including top and bottom view for placement of all the components on veroboard. Join us after the break to watch [myvideoisonutube] demo his version.
Continue reading “5 Digit Security Code Activated Relay Using Mostly Discrete Circuitry”