近年來 RFID 的應用無所不在,日常應用的電梯鎖就是利用RFID的機制來完成感應式開鎖的功能
Jason Chin 2019/9/25
RFID(Radio Frequency IDentification) 是一種以 RF 無線電波辨識物件的自動辨識技術,利用讀取機讀取貼附或植入在物件上的電子標籤(Tag 或又稱 Transponder)
市面上可以在電料行買到的是如下圖的 RFID 模組, RFID-RC522 讀取器上的 IC 是採用 NXP 的 RC522 , 那麼Jason 就以這個型號來進行實作測試
套件中總共有三個元件,一為讀取器電路板, 一個鑰匙扣,一張卡片
先到 Arduino 官網上去找有關 RFID 的 Library (rfid-master.zip)
將Library (rfid-master.zip)下載,並安裝到 Arduino 目錄中的 Libraries 子目錄中
硬體的接線方式,如下圖,由於 Jason 用的是 Arduion UNO,所以參考 UNO 那欄的接法即可
———————————————————————————————————-
* MFRC522 Arduino Arduino Arduino Arduino Arduino
* Reader/PCD Uno/101 Mega Nano v3 Leonardo/Micro Pro Micro
* Signal Pin Pin Pin Pin Pin Pin
* ——————————————————————————————————-
* RST/Reset RST 9 5 D9 RESET/ICSP-5 RST
* SPI SS SDA(SS) 10 53 D10 10 10
* SPI MOSI MOSI 11 / ICSP-4 51 D11 ICSP-4 16
* SPI MISO MISO 12 / ICSP-1 50 D12 ICSP-1 14
* SPI SCK SCK 13 / ICSP-3 52 D13 ICSP-3 15
如下是詳細的程式
/*
* ———————————————————————————————————
* Example sketch/program showing how to read data from a PICC to serial.
* ———————————————————————————————————
* This is a MFRC522 library example; for further details and other examples see: https://github.com/miguelbalboa/rfid
*
* Example sketch/program showing how to read data from a PICC (that is: a RFID Tag or Card) using a MFRC522 based RFID
* Reader on the Arduino SPI interface.
*
* When the Arduino and the MFRC522 module are connected (see the pin layout below), load this sketch into Arduino IDE
* then verify/compile and upload it. To see the output: use Tools, Serial Monitor of the IDE (hit Ctrl+Shft+M). When
* you present a PICC (that is: a RFID Tag or Card) at reading distance of the MFRC522 Reader/PCD, the serial output
* will show the ID/UID, type and any data blocks it can read. Note: you may see “Timeout in communication” messages
* when removing the PICC from reading distance too early.
*
* If your reader supports it, this sketch/program will read all the PICCs presented (that is: multiple tag reading).
* So if you stack two or more PICCs on top of each other and present them to the reader, it will first output all
* details of the first and then the next PICC. Note that this may take some time as all data blocks are dumped, so
* keep the PICCs at reading distance until complete.
*
* @license Released into the public domain.
*
* Typical pin layout used:
* —————————————————————————————–
* MFRC522 Arduino Arduino Arduino Arduino Arduino
* Reader/PCD Uno/101 Mega Nano v3 Leonardo/Micro Pro Micro
* Signal Pin Pin Pin Pin Pin Pin
* —————————————————————————————–
* RST/Reset RST 9 5 D9 RESET/ICSP-5 RST
* SPI SS SDA(SS) 10 53 D10 10 10
* SPI MOSI MOSI 11 / ICSP-4 51 D11 ICSP-4 16
* SPI MISO MISO 12 / ICSP-1 50 D12 ICSP-1 14
* SPI SCK SCK 13 / ICSP-3 52 D13 ICSP-3 15
*/
#include <SPI.h>
#include <MFRC522.h>
#define RST_PIN 9 // Configurable, see typical pin layout above
#define SS_PIN 10 // Configurable, see typical pin layout above
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance
void setup() {
Serial.begin(9600); // Initialize serial communications with the PC
while (!Serial); // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
SPI.begin(); // Init SPI bus
mfrc522.PCD_Init(); // Init MFRC522
mfrc522.PCD_DumpVersionToSerial(); // Show details of PCD – MFRC522 Card Reader details
Serial.println(F(“Scan PICC to see UID, SAK, type, and data blocks…”));
}
void loop() {
// Look for new cards
if ( ! mfrc522.PICC_IsNewCardPresent()) {
return;
}
// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial()) {
return;
}
// Dump debug info about the card; PICC_HaltA() is automatically called
mfrc522.PICC_DumpToSerial(&(mfrc522.uid));
}
如下是執行的結果,經過實測,鑰匙扣型的大約在接近讀取器3cm 距離內,卡片在5cm 距離內,才可被讀取良好,經由 monitor 畫面如下:
以下是實作的相片,供讀者參考,謝謝
