How to Scan RFID Tags with Arduino!

welcome back to the Master Tech and in today's video I'm going to show you how to read RFID scans from components like key cards and key fobs using a microcontroller like an Arduino or a Raspberry [Music] Pi so the core functionality in this project is obviously RFID which stands for radio frequency identification and there are so many little sub technologies that we deep dive around the world of RFID Communications this will be a practical video on how to use RFID scanning for an Arduino or a comparable microcontroller project but for today's video all you really need to know about how an RFID Loop works is that there is a master or a powered active component that is sort of going out and emitting a radio frequency and looking for nearby devices to scan and for this application that'll be this standard mfrc 522 RFID scanning component it uses a very simple 8 Pin pinout which is very standard for RFID scanners and then passive components things that don't require power because they have an RF signature an RF id but they're not powered because all they need to be is near an active component that's able to scan them like this key fob or this key card so if you understand the difference between active and passive you know enough about RFID that you can use it for this project the eight pins I previously mentioned are built around around serial peripheral Communications usually abbreviated SPI and in our application it's 3.3 volts and ground for the power Loop and then SDA which is serial data sck which is serial clock miso which is Master in slave out and M oi which is Master out slave in then irq which means interrupt request and rst which means reset you can find little variations on these pins some use uh slave select or chip select as well um but we're not going to worry about that today it is worth mentioning and calling out now that the majority of the kits and scanners that I saw that are Arduino compatible don't come with the pins soldered on so I know some folks uh have found my videos before and they mentioned that I never said anything about you having to solder if you use the exact kits that I use in this video you will need to solder your components so if you don't want to do that just make sure you look for a similar kit that comes with the pins already attached now let's take a look at the physical wiring for our project the piece that you actually need to know about our physical connections here is we want to take 3.3 volts and ground from the scanner to the same pins on the Arduino then I'm going to use pins 9 10 11 12 and 13 for the rest of the connections N9 for reset 10 for SDA 11 for MOSI 12 for miso and 13 forck in this application we don't need the irq pin so don't worry about that one and those physical hookups to an Arduino is all we need to get the RFID scanner working I'm going to add a breadboard with six LEDs just hooked up to six open Digital pins so that I can make an interesting example in the next step but all we need for the RFID scanner to work is those first seven wires we talked about now let's go quickly look at some of the code here in the Arduino IDE go to tools then manage libraries and search for mfrc522 I'm using this one from GitHub community that comes with several great examples so install this library then hit the little three dots in the top right corner of that library in the library tools and go to examples then open the one that's called read nuid this is going to have some simple code to get us going really fast with just reading the rfids and then I'll show you my custom code for checking and validating rfids against a bank of stored and trusted codes now if you're a code efficient Auto or you're really trying to understand a layer deeper of how RFID works I welcome you to pause here a little bit go through this example code and really understand what each line is doing but I'm going to summarize it for you it's basically importing the libraries that you need to get going and then the sensor is actively listening for a new RFID chipped device when one comes close enough that it can read it it just prints it to the serial window that's basically the whole point of this read nuid example code and so let's put it onto our Arduino real real quick Let's scan a few devices and let's see what happens and what you can see is I'm scanning these unique IDs and they're being displayed in four bytes stored in heximal format that's really important because when you save these codes in an array or some Bank of trusted codes that you want to use going forward you have to make sure to get both the data type which is bytes in this case and the format which is heximal you have to get both of those correct or it won't copy over appropriately and then your comparison logic won't work right so I'm going to write down all six of the codes that I have uh here on the devices in front of me and I'm going to use these in the next example and just before we dive into the next example I want to take a moment to thank the sponsor of today's video PCB way PCB way has everything makers and hobbyists need to take their hobby designs and turn them into highquality production level Parts while they specialize in printed circuit boards and printed circuit board assembly they also have everything you need to turn highquality 3D printed parts and metal CNC prototypes around in no time at all every time I've worked with PCB way the service has been extremely high quality pricing is super reasonable and the turnaround time is great so be sure to check them out and thank you to PCB way for sponsoring today's video now I want to use the six LEDs to indicate if the RFID I just scanned was one of the trusted codes and if it is then I want to light up the spot in that LED bank for that code so I have 1 through six I'm going to store them in an array so they'll have indexes 0 through 5 and I want these lights to light up if I scan a certain one so light five should light up if I scan the fifth RFID tag light 1 2 3 4 Etc and the code component of this is very simple you just have to sort of modify that read nuid to then take the scanned code and check against an array uh kind of iterate through a for Loop and of course I'm going to leave it linked in a get Hub below so if you want to grab that start from that code start poking around and making it your own feel free to take that and let me know as always with any questions you have around the code in the comments below I'll get back to you as soon as I can so let's go ahead and scan a few devices see how the circuit reacts and talk about what's happening and what you can see when I scan RFID tag one the first light lights up the rest of them blink indicating it's a bad match RFID 2 the second light lights up and etc etc so you can think of a system where you might want students to scan badges or tags when they check in some sort of system where you provide an employee perk and you want to track who's using it so you set up a badge scanner and in a pretty minimal way this is sort of how employee access systems at work your credit card when it's being chip scanned at checkouts and all sorts of other local scanning RFID type Technologies are working so having a basic understanding of this is super cool not just for hobbyists and makers but as you go go about the world seeing this in regular use and knowing hey I know what's going on in there all right so I hope yall found this video to be a useful introduction to the world of RFID scanning with Arduino and microcontrollers let me know if you have any questions in the comments below and drop a comment telling me what we should do next please consider leaving a like on the video subscribing to the channel it helps me out a ton and if you love the content we're doing on the channel go ahead and check out my patreon link it's in the description of the video as well thank you so much to my patreon support orders and thank you to everyone for watching we'll see you next time good luck with your projects bye