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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：

​ (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")

函数调用

此时，您可以通过调用库的方式来实现简单的功能。

如果您想要读取卡的相关信息的话，可以通过下面两行代码进行实现：

import read
read.do_read()

如果您想将信息写入卡的话，可以通过下面两行代码进行实现：

import write
write.do_write()

结尾

本文中出现的代码大部分是在GitHub开源库中搬运过来，并在原有基础上加以修改。

参考文献：

• GitHub源码地址