Have you ever wondered how to utilize an RFID (Radio Frequency Identification) reader with a NodeMCU? In this tutorial, we will delve into the step-by-step process of effectively using the RC522 RFID reader with a NodeMCU. The RC522 is an inexpensive RFID reader that can be easily integrated with various boards such as Arduino, Raspberry Pi, or NodeMCU. It operates at a frequency of 13.56 megahertz and can be powered by 2.54 to 3.3 volts. Additionally, it utilizes SPI communication and can read tags up to 5 centimeters away, with a current consumption of approximately 13 to 26 milliamps.
To begin, let’s take a look at the wiring diagram required for this setup:
[INSERT WIRING DIAGRAM]
Once the wiring is complete, open the Arduino IDE. You can find the complete code and library to download on my website. I have simplified the code compared to the example in the library to make it easier to understand.
In the code, you will need to include the library and define the necessary pins for the RC522 reader. The reset pin is connected to D3, while the access pin is connected to D4. We also create a string variable called tag to store the tag serial number. Additionally, we initialize the SPI and RFID modules. If a card is detected, the RFID reader will read the tag’s serial number, which will be displayed in the serial monitor.
To test the RFID reader with the NodeMCU, upload the code to the board. Upon completion, you should see a unique tag serial number printed on the serial monitor each time a card is tapped on the RFID reader.
Now, let’s take it up a notch and create a program with enhanced functionality. This program will produce a distinct sound and print “Access Granted” on the serial monitor when the correct RFID card, in this case, a blue keychain, is tapped. Conversely, when an incorrect RFID card (in this case, a white card) is tapped, the program will print “Access Denied” and emit a long buzzer sound for 2 seconds.
To implement this program, you will need to copy the UID of the blue keychain and paste it into the code. Connect the positive terminal of the buzzer to pin A0. The complete program can be found on my website.
When you tap the blue keychain tag, you will see the UID and “Access Granted” printed on the serial monitor. Conversely, if you tap the white card, the program will print “Access Denied.”
In conclusion, this tutorial has provided a comprehensive guide on how to effectively use the RC522 RFID reader with a NodeMCU. By following these steps, you can seamlessly integrate an RFID reader into your NodeMCU projects. Stay tuned for more tutorials, and don’t forget to like, share, and subscribe! Thank you for watching.
