RFID stands for radio frequency identification. This technology makes use of electromagnetic fields to identify objects in a contactless way. It is widely used in access cards and public transport cards.
Here you can find some examples of what you can achieve with RFID and Arduino.
NFC Door Lock
This is a very common application for NFC. With a card, a reader and some additional components you can make your own contactless door lock. This door lock is controlled by a Qduino Mini, because it fits perfectly, but any Arduino compatible board will do the job.
Qtechknow used a servo to drive the locking bolt, and several 3d-printed parts to make a housing and mount everything on the door. So the NFC shield, the board and a LiPo battery are placed inside this casing on the door lock.
Now you just have to put your card close enough to the reader, and when the NFC tag is detected the board activates the servo and it unlocks the door.
Here's a completely different project, nothing to do with security or access control. Philippe made his own interactive RGB/RFID lamp from scratch.
By placing different colored tags close to the hidden reader you can change the color, a black disc is used to turn off the lamp and a white disc to make a white light. The lamp changes color randomly when it doesn't detect any tag.
The lamp is controlled by an Arduino Uno board and all the different colors are made by a strip of RGB LEDs, driven by the PWM pins of the Arduino. The pins are connected through Mosfet transistors, and controlling the voltage in each channel you can change the color.
The RFID reader is connected to digital pins 8 & 9, and the system is powered by a 12V wall transformer. A small LED, connected on digital pin 7, indicates when the RFID reader is ready to read, and a piezo speaker on pin 10 is used to add sound to the lamp.
He designed with frizting a custom shield integrating all the electronics for the lamp. The shield is a single side PCB and is mounted on top of the Arduino.
The housing of the lamp was designed with SketchUp and made out of plywood and pine pieces, and the LED strip is wrapped around a PCV pipe.
The Arduino with the shield are attached at the bottom of the wood box and the RFID reader is placed under the disc holder.
The color discs are also made out of plywood, each one containing a different RFID tag.
Take a look at our own LED Lamp controlled with RFID tags here.
RFID Car Starter
This is a pretty cool hack of a car starter system. Pierre wanted to customize his new car and added this incredible feature to start the engine with an RFID tag.
He placed a 13.56 MHz RIFD reader on the dashboard, so the tag has to be held for over a second and the car starts. Then to turn it off he just have to hold it again for a second.
An Arduino Nano receives the info from the reader and controls a relay module with two relays that start or shut down the engine. All the components are cleverly hidden under the armrest and on the dashboard so it is amazing to see it working. Check it out in the video above.
Posted on Hackaday.
Don't forget to take a look at our own RFID/NFC kits and modules for Arduino, Raspberry Pi, Waspmote and Intel Galileo. Click here.