ESP32开发之旅——RC522模块的使用

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发布于 2022-09-14 09:33:54

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发布于 2022-09-14 09:33:54

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ESP32开发之旅——RC522模块的使用

前言

在本文中，您将学会如何使用ESP32连接RFID模块RC522，本文提供了简单的示例供学习参考。
需要注意的是，本文中的ESP32是使用Micro Python进行开发的,（同时ESP8266也可按照本文进行开发）。
本文中出现的代码是从GitHub开源库中搬运而来，GitHub链接已放在文尾。

RFID-RC522模块的简单介绍

射频识别RFID（Radio Frequency Identification）是一种无线数据传输系统，用于在标签和读取器设备之间传输数据，而RC522模块则是用于读取和写入RFID卡和标签，该模块的工作频率为13.56MHz。

正文

所需材料

ESP32开发板（已刷入MicroPython固件，未刷入的小伙伴可以参考我前面的教程）
RC522读卡器以及对应频率的RFID卡
Thonny（其他支持MicroPython开发的IDE皆可）

连线说明

在RC522模块上共有8个引脚，实际上我们只需使用7个引脚就可以完成本次的开发。引脚对应表如下：

Signal	SCK	MOSI	MISO	RST	CS(SDA)
ESP32/ESP8266	P0	P2	P4	P5	P14

(注意：VCC与GND在表格中未标出来，但也需要连接，且VCC使用3.3V电源)

核心代码

mfrc522.py

from machine import Pin, SPI
from os import uname

class MFRC522:

    OK = 0
    NOTAGERR = 1
    ERR = 2

    REQIDL = 0x26
    REQALL = 0x52
    AUTHENT1A = 0x60
    AUTHENT1B = 0x61

    def __init__(self, sck, mosi, miso, rst, cs):

        self.sck = Pin(sck, Pin.OUT)
        self.mosi = Pin(mosi, Pin.OUT)
        self.miso = Pin(miso)
        self.rst = Pin(rst, Pin.OUT)
        self.cs = Pin(cs, Pin.OUT)

        self.rst.value(0)
        self.cs.value(1)
        
        board = uname()[0]

        self.spi = SPI(baudrate=100000, polarity=0, phase=0, sck=self.sck, mosi=self.mosi, miso=self.miso)
        self.spi.init()

        self.rst.value(1)
        self.init()

    def _wreg(self, reg, val):

        self.cs.value(0)
        self.spi.write(b'%c' % int(0xff & ((reg << 1) & 0x7e)))
        self.spi.write(b'%c' % int(0xff & val))
        self.cs.value(1)

    def _rreg(self, reg):

        self.cs.value(0)
        self.spi.write(b'%c' % int(0xff & (((reg << 1) & 0x7e) | 0x80)))
        val = self.spi.read(1)
        self.cs.value(1)

        return val[0]

    def _sflags(self, reg, mask):
        self._wreg(reg, self._rreg(reg) | mask)

    def _cflags(self, reg, mask):
        self._wreg(reg, self._rreg(reg) & (~mask))

    def _tocard(self, cmd, send):

        recv = []
        bits = irq_en = wait_irq = n = 0
        stat = self.ERR

        if cmd == 0x0E:
            irq_en = 0x12
            wait_irq = 0x10
        elif cmd == 0x0C:
            irq_en = 0x77
            wait_irq = 0x30

        self._wreg(0x02, irq_en | 0x80)
        self._cflags(0x04, 0x80)
        self._sflags(0x0A, 0x80)
        self._wreg(0x01, 0x00)

        for c in send:
            self._wreg(0x09, c)
        self._wreg(0x01, cmd)

        if cmd == 0x0C:
            self._sflags(0x0D, 0x80)

        i = 2000
        while True:
            n = self._rreg(0x04)
            i -= 1
            if ~((i != 0) and ~(n & 0x01) and ~(n & wait_irq)):
                break

        self._cflags(0x0D, 0x80)

        if i:
            if (self._rreg(0x06) & 0x1B) == 0x00:
                stat = self.OK

                if n & irq_en & 0x01:
                    stat = self.NOTAGERR
                elif cmd == 0x0C:
                    n = self._rreg(0x0A)
                    lbits = self._rreg(0x0C) & 0x07
                    if lbits != 0:
                        bits = (n - 1) * 8 + lbits
                    else:
                        bits = n * 8

                    if n == 0:
                        n = 1
                    elif n > 16:
                        n = 16

                    for _ in range(n):
                        recv.append(self._rreg(0x09))
            else:
                stat = self.ERR

        return stat, recv, bits

    def _crc(self, data):

        self._cflags(0x05, 0x04)
        self._sflags(0x0A, 0x80)

        for c in data:
            self._wreg(0x09, c)

        self._wreg(0x01, 0x03)

        i = 0xFF
        while True:
            n = self._rreg(0x05)
            i -= 1
            if not ((i != 0) and not (n & 0x04)):
                break

        return [self._rreg(0x22), self._rreg(0x21)]

    def init(self):

        self.reset()
        self._wreg(0x2A, 0x8D)
        self._wreg(0x2B, 0x3E)
        self._wreg(0x2D, 30)
        self._wreg(0x2C, 0)
        self._wreg(0x15, 0x40)
        self._wreg(0x11, 0x3D)
        self.antenna_on()

    def reset(self):
        self._wreg(0x01, 0x0F)

    def antenna_on(self, on=True):

        if on and ~(self._rreg(0x14) & 0x03):
            self._sflags(0x14, 0x03)
        else:
            self._cflags(0x14, 0x03)

    def request(self, mode):

        self._wreg(0x0D, 0x07)
        (stat, recv, bits) = self._tocard(0x0C, [mode])

        if (stat != self.OK) | (bits != 0x10):
            stat = self.ERR

        return stat, bits

    def anticoll(self):

        ser_chk = 0
        ser = [0x93, 0x20]

        self._wreg(0x0D, 0x00)
        (stat, recv, bits) = self._tocard(0x0C, ser)

        if stat == self.OK:
            if len(recv) == 5:
                for i in range(4):
                    ser_chk = ser_chk ^ recv[i]
                if ser_chk != recv[4]:
                    stat = self.ERR
            else:
                stat = self.ERR

        return stat, recv

    def select_tag(self, ser):

        buf = [0x93, 0x70] + ser[:5]
        buf += self._crc(buf)
        (stat, recv, bits) = self._tocard(0x0C, buf)
        return self.OK if (stat == self.OK) and (bits == 0x18) else self.ERR

    def auth(self, mode, addr, sect, ser):
        return self._tocard(0x0E, [mode, addr] + sect + ser[:4])[0]

    def stop_crypto1(self):
        self._cflags(0x08, 0x08)

    def read(self, addr):

        data = [0x30, addr]
        data += self._crc(data)
        (stat, recv, _) = self._tocard(0x0C, data)
        return recv if stat == self.OK else None

    def write(self, addr, data):

        buf = [0xA0, addr]
        buf += self._crc(buf)
        (stat, recv, bits) = self._tocard(0x0C, buf)

        if not (stat == self.OK) or not (bits == 4) or not ((recv[0] & 0x0F) == 0x0A):
            stat = self.ERR
        else:
            buf = []
            for i in range(16):
                buf.append(data[i])
            buf += self._crc(buf)
            (stat, recv, bits) = self._tocard(0x0C, buf)
            if not (stat == self.OK) or not (bits == 4) or not ((recv[0] & 0x0F) == 0x0A):
                stat = self.ERR

        return stat

read.py

import mfrc522
from os import uname
import time

def do_read():
    rdr = mfrc522.MFRC522(0, 2, 4, 5, 14)
    index = True ###用于标记是否读到卡片
    try:
        while True:
            (stat, tag_type) = rdr.request(rdr.REQIDL)
            if stat == rdr.OK:
                (stat, raw_uid) = rdr.anticoll()
                if stat == rdr.OK:
                    print("识别到卡片：")
                    print("uid: 0x%02x%02x%02x%02x" % (raw_uid[0], raw_uid[1], raw_uid[2], raw_uid[3]))
                    print("")
                    index = False
                  	if rdr.select_tag(raw_uid) == rdr.OK:
    
                        key = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]

                        if rdr.auth(rdr.AUTHENT1A, 8, key, raw_uid) == rdr.OK:
                            print("Address 8 data: %s" % rdr.read(8))
                            rdr.stop_crypto1()
                        else:
                            print("Authentication error")

    except KeyboardInterrupt:
        print("Bye")

write.py

import mfrc522
from os import uname
def do_write():
    rdr = mfrc522.MFRC522(0, 2, 4, 5, 14)
    try:
        while True:
            (stat, tag_type) = rdr.request(rdr.REQIDL)
            if stat == rdr.OK:
                (stat, raw_uid) = rdr.anticoll()
                if stat == rdr.OK:
                    print(" - uid: 0x%02x%02x%02x%02x" % (raw_uid[0], raw_uid[1], raw_uid[2], raw_uid[3]))
                    print("")

                    if rdr.select_tag(raw_uid) == rdr.OK:

                        key = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]

                        if rdr.auth(rdr.AUTHENT1A, 8, key, raw_uid) == rdr.OK:
                            stat = rdr.write(8, b"这里输入你要写入的数据,16进制")
                            rdr.stop_crypto1()
                            if stat == rdr.OK:
                                print("数据已写入")
                            else:
                                print("数据写入失败")
                        else:
                            print("Authentication error")
                    else:
                        print("Failed to select tag")

    except KeyboardInterrupt:
        print("Bye")