NFC Business Card - PCB

A business card that lights up when you tap it with your phone. No battery. It just steals power from the phone's NFC radio.

Built for Horizons Polaris Hack Club

Features

• Energy Siphoning: It harvests power directly from your phone's NFC field.

• Open Sourced: Change the copper layers and mask to add whatever text or logo you want.

• LEDs: 4 LEDs light up faintly when you tap the card (Whoa cool lights!)

• NFC: Uses the NXP NT3H1101 chip. Just tap and it sends your info.

Hardware

• Size: Standard credit card (85.6mm x 54mm). yes I had to google how big a credit card is... Two layers (duh its not gonna be six layers)

• NFC Chip: NXP NT3H1101W0FHKH (XQFN-8). (basically small ahh chip)

• Antenna: Copper traces in a loop, idk how many loops matter but I did a couple.

• Harvesting: 220nF capacitor to store the tiny bit of power the phone gives off.

• LEDs: 4x low forward voltage warm white LEDs (0603). (low power needed LEDs)

• Resistors: 4x 220Ω current limiters + 2x 0Ω jumpers (all 0603).

• PCB Finish: Black soldermask + ENIG gold finish. The black paint covers the board, and the text/QR code is exposed copper plated in gold so it pops.

Bill of Materials (BOM)

Designator	Value / Description	LCSC Part #
U1	NT3H1101W0FHKH NFC IC (XQFN-8)	C73156
R6, R5	0Ω Zero-ohm Jumpers (0603)	C95177
C1	220nF Capacitor (0603)	C64705
U2, U3, U4, U5	Low VF Warm White LEDs (0603)	C965810
R1, R2, R3, R4	220Ω Resistors (0603)	C2907014
Costs are dependent on shipping location!

Steps to Reproduce

If you want to customize/change the design of the PCB, download the files in the PCB folder and open in KiCad and change them! For manufacturing, download the gerbers.zip in the Production Folder and give them to the corresponding PCB manufacturer(JLCPCB) After you receive your PCBs, read below!

Firmware / Programming

It doesn't run code. The chip just stores a URL that your phone reads. Here’s how to set it:

1. Download "NFC Tools" on your phone (iOS or Android). We all love downloading an app for one specific thing!

2. Tap the card to your phone. (Put your phone to the contactless symbol! That's why I put it there as a silkscreen).

3. Open the app, go to Write > Add a record > URL.

4. Paste your link (GitHub, LinkedIn, whatever).

5. Hit Write and tap the card again.

6. Gain massive amounts of aura for having a PCB as your business card (Patrick Bateman who??)

Schematic

PCB

Front:

Black soldermask + ENIG gold finish

Back:

Black soldermask + ENIG gold finish