RFID reader on a Raspberry Pi
Counting Pumpkins
© Lead Image © raspberrypi.com
Inexpensive components for the SPI interface let you upgrade a Raspberry Pi 4 to a display system for zero-contact RFID-based data acquisition.
Radio-frequency identification (RFID) tags have become indispensable in industry and government, as well as the wholesale and retail spaces. The inexpensive transponder chips can be found on clothing labels, identification cards, and credit cards. Armed with just a Raspberry Pi and an RFID kit, you can read the data from these chips and view it on a display.
In this project, I read serial numbers from RFID tags stuck on 3D-printed pumpkins – a slightly different kind of detection task. To do this, I connect an RC522 [1] RFID kit and a 1.8-inch ST7735 serial peripheral interface (SPI) thin-film transistor (TFT) display [2] to a Raspberry Pi 4. Together, the two modules can cost less than $15 (EUR15, £14) in online stores. The pumpkins contain simple RFID tags [3], also available for very little cash. Although at first glance the project seems clear-cut and sounds as if it should work right away, check out the "Mishaps, Misfortunes, and Breakdowns" box to find out what can go wrong.
The circuit diagram in Figure 1 shows how the modules connect to the Raspberry Pi, along with two pushbuttons and LEDs for testing purposes. The KiCad layout of the project is included in the download section of this article [4].
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Linux Mint 22.3 Now Available with New Tools
Linux Mint 22.3 has been released with a pair of new tools for system admins and some pretty cool new features.
-
New Linux Malware Targets Cloud-Based Linux Installations
VoidLink, a new Linux malware, should be of real concern because of its stealth and customization.
-
Say Goodbye to Middle-Mouse Paste
Both Gnome and Firefox have proposed getting rid of a long-time favorite Linux feature.
-
Manjaro 26.0 Primary Desktop Environments Default to Wayland
If you want to stick with X.Org, you'll be limited to the desktop environments you can choose.
-
Mozilla Plans to AI-ify Firefox
With a new CEO in control, Mozilla is doubling down on a strategy of trust, all the while leaning into AI.
-
Gnome Says No to AI-Generated Extensions
If you're a developer wanting to create a new Gnome extension, you'd best set aside that AI code generator, because the extension team will have none of that.
-
Parrot OS Switches to KDE Plasma Desktop
Yet another distro is making the move to the KDE Plasma desktop.
-
TUXEDO Announces Gemini 17
TUXEDO Computers has released the fourth generation of its Gemini laptop with plenty of updates.
-
Two New Distros Adopt Enlightenment
MX Moksha and AV Linux 25 join ranks with Bodhi Linux and embrace the Enlightenment desktop.
-
Solus Linux 4.8 Removes Python 2
Solus Linux 4.8 has been released with the latest Linux kernel, updated desktops, and a key removal.

