NFC Enabled Invitations Cards (+ Analytics for a Sri Lankan Wedding)

Invitation cards are one of the key components of a big event. It provides a description of the event, time, venue, dress code and other important information the invitee needs to know. These are generally a one way mode of communication. The organizer hands out the invitation card to the invitees, the invitees make a note of the details and that's the end of that.

For my wedding I wanted to push the limits of wedding invitation cards in order to provide some ease for the invitees. In order to achieve this I pasted a cheap NFC tags to the back of each invitation card with a simple message to describe what it is. As some people do not prefer this, the NFC can also be embedded within the invitation card for a premium feel.

The purpose of using an NFC tag was so that I can allocate a unique identification code to each invitation and link it to a table number or any other information that is needed. Generally table numbers are not known when handing out the invitation cards. These are usually assigned closer to the day of the event and the guests can scan their invitation cards at the entrance on the day of the event and be presented with their table number(s). However, as I was working on this project as a hobby, a number uses for this presented itself.

Benefits of using the NFC tag.

• Added security - Officials at the event location can scan the invitation card to verify the identity of the invitee
• Avoid congestion & crowding - Invitee can avoid the queue to check the table numbers at the entrance
• Custom messages - Invitees can be displayed with a custom message on arrival
• Photo booth - Scanning the invitation can launch a photo-booth that can take the picture of the invitee and automatically email it to them.

For this project, I used a Raspberry Pi 3B running a fresh copy of Raspbian and connected it to a MFRC 522 RFID module capable of reading NTags operating at 13.56MHz. The Raspberry Pi was connected to a screen at the hotel to display the data and the scanner was fixed to the front of the screen, with the holder disguised with floral decor.

Each invitation card was equipped with an NFC NTag 213 sticker on the back. Each sticker has a built in identification number which was scanned and allocated to an invitee before handing them out. This UID is used to identify the invitee when scanned.

The software on the Raspberry Pi was coded with Python and Kivy to show an image of the couple along with a welcome message and a note to hold the invitation card against the scanner. When the card is scanned, the welcome message disappears and the names of invitees allocated to the card, relevant table numbers, and a custom message is shown on the screen.

According to the software that I wrote, each invitation card can hold up to two sets of invitees on two different tables. This is especially useful is the parents and children are to be seated separately.

In addition to this, one of the requested features for this was a custom message for each invitee. A little inside joke or a custom greeting can also be placed here. This field will be replaced with a standard greeting if no message is added.

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NFC enabled invitation card scanner 📷 @flipside_imaging

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One of the most interesting by products from the success of this project was the analytics. I learned that only 53% of the invitees have actually remembered to bring their invitation cards, while 44% have forgotten to bring their cards or ignored/forgotten to scan the card at the entrance.

The typical show up time for guests was about one hour to one and half hours after the start of the event and each guests scans an average of 1.8 times in order to remember their table number.

With the growing number of online invitations (e-invites), it may not be practical to use physical NFC tags. As such I have upgraded by system to work with both NFC tags or with scanned barcodes or QR codes that can be texted to the invitee with the e-invite.