I recently made this project which involves an Arduino Leonardo and Adafruit’s NFC Shield. The premise of the project is that when you place a specified NFC tag on the shield, it unlocks your computer. I even designed a 3D case that mounts it underneath your desk!
…Quit pulling your hair out over incorrect passwords. Using an Arduino Leonardo and Adafruit’s NFC shield, you can unlock your computer with an NFC card. The Arduino reads the NFC card’s unique identifier and once it receives the correct one, it uses the Arduino Leonardo’s keyboard emulation feature to type a password.
Adafruit PN532 NFC/RFID Controller Shield for Arduino + Extras: We’ve taken our popular Adafruit PN532 breakout board and turned it into a shield – the perfect tool for any 13.56MHz RFID or NFC application. The Adafruit NFC shield uses the PN532 chip-set (the most popular NFC chip on the market) and is what is embedded in pretty much every phone or device that does NFC. This chipset is very powerful, and can pretty much do it all, such as read and write to tags and cards, communicate with phones (say for payment processing), and ‘act’ like a NFC tag. While the controller has many capabilities, our Arduino library currently only supports reading/writing tags, and does not support phone-to-shield communication, tag emulation (which requires an external ‘secure element’ only available from NXP) or other more advanced features at this time. NFC (Near Field Communications) is a way for two devices very close to each other to communicate. Sort of like a very short range bluetooth that doesn’t require authentication. It is an extension of RFID, so anything you can do with RFID you can do with NFC. Because it can read and write tags, you can always just use this for RFID-tag projects. We carry a few different tags that work great with this chip. It can also work with any other NFC/RFID Type 1 thru 4 tag (and of course all the other NXP MiFare type tags) (read more)
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.