It uses NXP LPC8N04, and features nine 0.4 mm slim orange LEDs for the light show and feedback. The MCU itself consumes only 900uA at 8MHz and 200uA at 1MHz. Given that NFC readers provide power continuously, there are many application that could be implemented on the business card. I haven't came up with anything fancy yet, except for hooking up I2C sensors, and using LEDs and time interval that card is held against the NFC reader to change the mode of operation. If you have any ideas, leave the comment below!
I'm a high school student in China,half an electronics enthusiast,and I pretty intersted in your project.About 2 years ago I have seen this project.Recently, I began to refer to your project to make a water card that can flash.I have little knowledge to done it well.The school do not allow me to carry electronic devices, so I printed some official documents of NXP(About LPC8N04 DataSheet and NTAG Antenna Design Guide) and went to the school to read them in free time,sometimes in class.I wish to get your advice in some simple questions.The antenna input capacitor is 1.2pf in your schematics,and I refer to antenna desgin guide about LC equivalent circuit part is recommand use the 50pf one.I had did some calculations,results is 2-3uH inductance 1.2pf capacitor the resonance frequency is up to 100MHz,is much over the NFC resonance frequency which is 13.56MHz.I feel confused here. I hope you can reply.Thanks~