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NFC Card: The Secrets Behind Near Field Communication

Are you looking for a way to transfer data from one device to another within a close range? Or perhaps, you’re looking for a technology to handle your contactless payment issues? Then, try building an NFC card.

NFC technology is wireless and allows for accessible communication between two devices. Plus, NFCs have intuitive interfaces that enable large wireless networking platforms to work seamlessly.

However, we’ll walk you through the secrets of Near field communication and how to make an  NFC card with PCB.

What is an NFC Card?

NFC cards use near-field communication technology to allow contactless communication between two devices over a short distance.

However, the communication distance is only about 4cm or less.

NFC cards can serve as keycards or electronic identity documents. They also work in contactless payment systems and even enable mobile payments.

Plus, NFC devices can replace or supplement existing payment systems like electronic ticket intelligent cards or credit cards.

Also, you sometimes call NFC cards CTLS NFC or NFC/CTLS. Here, CTLS is simply an abbreviated form for contactless.

You can also use NFC to share small files like contacts. Also, it allows for bootstrapping faster connections for sharing larger files like videos and photos.

Interestingly, this bootstrapping complements the NFC’s initial slow connection that only allows for small file transfers.

Additionally, NFC cards make it easier to initiate connections with NFC-enabled devices, especially when compared to Bluetooth and other forms of wireless technology.

How do NFC Tags Work?

NFC on a Mobile Phone

NFC on a Mobile Phone

In truth, there are different sizes and shapes of NFC tags. And the ones you’d often see are square or circular-shaped stickers.

In short, these cards have simple principles: a thin copper coil and a tiny microchip storage space.

Now, the coil uses the process of electromagnetic induction to receive power from an NFC reader. Hence, bringing an NFC reader (with a passion) close to the card will energize it.

Then, the card can transmit any data stored on its microchip to the NFC device.

Additionally, you can add public-key encryption to NFC cards if you’re dealing with sensitive data. Or if you want to prevent other forms of malicious attacks.

Moreover, the NFC tag has a straightforward design that can fit into different form factors. These form factors range from small stickers to plastic cards the size of a credit card.

Also, NFC devices like tablets and smartphones can serve as NFC tags. It contrasts with the RFID, which only allows one-way communication. 

Hence, your phone can emulate an embedded NFC tag and work for contactless payments. Although such devices are advanced, they still use the basic working principle.

Furthermore, NFC cards can work in any of the following modes:

  • NFC care emulation: NFC devices like smartphones work like smart cards. Thus, users can make payments without physical credit cards or debit cards.
  • NFC peer-to-peer: Two NFC devices can communicate and exchange information ad hoc.
  • NFC reader/writer: Devices with NFC enabled can read store information on NFC tags in smart posters or labels.

Types of NFC Tags

NFC Tags

NFC Tags

Source: Flickr

NFC tags have five sub-types with convenient labels from type 1 to type 5. Type 1 NFC tags have a maximum of 100kbps transfer speed. These tags are only helpful for storing URLs or WiFi passwords.

In contrast, Type 5 NFC tags can store up to thirty-two-kilo bytes of memory. While it’s not that great, it is a considerable improvement when considering the Type 1 NFC tag. 

Interestingly, the Type 5 tag is four times faster than a Type 1 tag. However, it’s still not enough data compared to a microSD card with the same physical size. 

But, you can use Type 5 NFC tags applications like access control and ticketing. Also, you can get extra features like better interference handling and tamper resistance capabilities.

Keep in mind that the more advanced an NFC tag is, the more expensive it’ll be to manufacture. When you consider the amount of data usually transferred with NFCs, you will find that the more primitive Type 1 and 2 tags would suffice for most applications.

Plus, Type 1 and 2 tags are more common and would cost you only a few cents. Also, NFC tags usually come with read-write functions, so you often use them without replacing them.

How to Make an NFC Card

You can make NFC business cards with PCBs and NFC stickers, better than paper business cards. The process is simple, and you can do it in just a few easy steps. Here are the components you need for this project:

  • NFC stickers (with ISO14443A and 13.56Mhz)
  • NFC write and read tool (both Andriod and IOS)
  • PCB services 
  • Paint (optional)

Steps

Step 1: Get your PCB

First, you need to design your PCB and send it for manufacturing or use DIY etching. You can start by creating a new PCB project on software like Easy EDA and outline a round, rectangular board.

Next, create a layer on top of your outline and add your name using the text tool.

Then, embed a QR code on that top layer using the image tool and QR code generator.

Now, complete add your other details to complete your bottom layer. And add your design or accent to personalize your card.

Finally, download your Gerber files and send them to a PCB service for manufacturing.

Step 2: Get your NFC Tag and Stick it.

NFC Stickers

NFC Stickers

Source: Flickr

Carefully remove your NFC sticker from its packaging and place it on your manufactured PCB card. It would help if you stuck it on the backside of your contactless card. 

Plus, you can paint your NFC sticker to match the color of your card. But this is optional.

Step 3: Program your NFC Card with your Mobile Device

Now it’s time to program your NFC card. You can use an app on your android device that can write and read tags with NFC. You can get the app here.

NFC Write and Read Andriod App

NFC Write and Read Andriod App

Source: Screenshot of Google Play Store

First, enable NFC on your android device. You can find this in your phone’s settings or quick settings. 

However, not all android phones have NFC functions. But you’ll find them on more recent phones.

Activate NFC Through Settings

Activate NFC Through Settings

Next, open your NFC app and navigate to the “Write Tag” menu on the sidebar. Then, use the custom URL option to paste any link to your contact information, like a Facebook page or Youtube channel.

Now save your record and click on the “Write option.” Next, follow the prompt that asks you to “Approach an NFC card,” and it’s complete when it displays “Tag written successfully.”

How to Write an Address to an NFC Tag

NFC Write and Read App

NFC Write and Read App

We previously mentioned that most recent phones come equipped with NFC hardware–making it easy to read and write NFC tags by making physical contact.

Additionally, you can follow the steps above to write an address or URL to your NFC tag successfully. 

Now depending on the content of your tag, you should see a pop-up asking you to complete an action. If your title has a URL, your device will browse the web. If you read a tag embedded in a pair of headphones, it’ll pair your devices.

Can you Hack NFC Cards?

Indeed, it’s possible to hack NFC cards, but it’s not an easy process. In truth, most NFC cards feature write protections that prevent unauthorized changes and tampering, especially for access control.

Applications 

NFC tags are versatile and work for various applications. Some of these applications include:

  • Financial payments
NFC Payments

NFC Payments

Source: Pixabay

  • Traffic
  • Advertisements
  • Books
  • Entertainment
  • Medical treatment
  • File sharing
NFC File Sharing

NFC File Sharing

Source: Gadget Helpline

In Closing

NFC Tags

Source: Wikimedia Commons

There is no limit to what you can do with NFC tags. Interestingly, you can program rewritable NFC tags to do anything you desire.

There are NFC tools that allow you to write an address, contact, WiFi, and even Bluetooth pair information to a tag.

There are even advanced applications like using NFC tags with automation apps to initiate actions like turning off a light.

Do you have any questions? You can always reach us here, and we’ll be sure to respond in no time.

Hommer Zhao
Hi, I am Hommer, the founder of WellPCB. So far, we have more than 4,000 customers worldwide. If you have any questions, you can feel free to contact me. I really appreciate any help you can provide.

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