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TF 卡 连接

接线说明

TF 卡模块ESP32-S3
MISOGPIO4
MOSIGPIO5
SCKGPIO6
CSGPIO7
VCC5V

tf.png

先导入 TF 卡模块

SD 卡模块
py
"""
MicroPython driver for SD cards using SPI bus.
Requires an SPI bus and a CS pin.  Provides readblocks and writeblocks
methods so the device can be mounted as a filesystem.
Example usage on pyboard:
    import pyb, sdcard, os
    sd = sdcard.SDCard(pyb.SPI(1), pyb.Pin.01_board.X5)
    pyb.mount(sd, '/sd2')
    os.listdir('/')
Example usage on ESP8266:
    import machine, sdcard, os
    sd = sdcard.SDCard(machine.SPI(1), machine.Pin(15))
    os.mount(sd, '/sd')
    os.listdir('/')
"""
 
from micropython import const
import time
 
 
_CMD_TIMEOUT = const(100)
 
_R1_IDLE_STATE = const(1 << 0)
# R1_ERASE_RESET = const(1 << 1)
_R1_ILLEGAL_COMMAND = const(1 << 2)
# R1_COM_CRC_ERROR = const(1 << 3)
# R1_ERASE_SEQUENCE_ERROR = const(1 << 4)
# R1_ADDRESS_ERROR = const(1 << 5)
# R1_PARAMETER_ERROR = const(1 << 6)
_TOKEN_CMD25 = const(0xFC)
_TOKEN_STOP_TRAN = const(0xFD)
_TOKEN_DATA = const(0xFE)
 
 
class SDCard:
    def __init__(self, spi, cs, baudrate=1320000):
        self.spi = spi
        self.cs = cs
 
        self.cmdbuf = bytearray(6)
        self.dummybuf = bytearray(512)
        self.tokenbuf = bytearray(1)
        for i in range(512):
            self.dummybuf[i] = 0xFF
        self.dummybuf_memoryview = memoryview(self.dummybuf)
 
        # initialise the card
        self.init_card(baudrate)
 
    def init_spi(self, baudrate):
        try:
            master = self.spi.MASTER
        except AttributeError:
            # on ESP8266
            self.spi.init(baudrate=baudrate, phase=0, polarity=0)
        else:
            # on pyboard
            self.spi.init(master, baudrate=baudrate, phase=0, polarity=0)
 
    def init_card(self, baudrate):
 
        # init CS pin
        self.cs.init(self.cs.OUT, value=1)
 
        # init SPI bus; use low data rate for initialisation
        self.init_spi(100000)
 
        # clock card at least 100 cycles with cs high
        for i in range(16):
            self.spi.write(b"\xff")
 
        # CMD0: init card; should return _R1_IDLE_STATE (allow 5 attempts)
        for _ in range(5):
            if self.cmd(0, 0, 0x95) == _R1_IDLE_STATE:
                break
        else:
            raise OSError("no SD card")
 
        # CMD8: determine card version
        r = self.cmd(8, 0x01AA, 0x87, 4)
        if r == _R1_IDLE_STATE:
            self.init_card_v2()
        elif r == (_R1_IDLE_STATE | _R1_ILLEGAL_COMMAND):
            self.init_card_v1()
        else:
            raise OSError("couldn't determine SD card version")
 
        # get the number of sectors
        # CMD9: response R2 (R1 byte + 16-byte block read)
        if self.cmd(9, 0, 0, 0, False) != 0:
            raise OSError("no response from SD card")
        csd = bytearray(16)
        self.readinto(csd)
        if csd[0] & 0xC0 == 0x40:  # CSD version 2.0
            self.sectors = ((csd[8] << 8 | csd[9]) + 1) * 1024
        elif csd[0] & 0xC0 == 0x00:  # CSD version 1.0 (old, <=2GB)
            c_size = (csd[6] & 0b11) << 10 | csd[7] << 2 | csd[8] >> 6
            c_size_mult = (csd[9] & 0b11) << 1 | csd[10] >> 7
            read_bl_len = csd[5] & 0b1111
            capacity = (c_size + 1) * (2 ** (c_size_mult + 2)) * (2**read_bl_len)
            self.sectors = capacity // 512
        else:
            raise OSError("SD card CSD format not supported")
        # print('sectors', self.sectors)
 
        # CMD16: set block length to 512 bytes
        if self.cmd(16, 512, 0) != 0:
            raise OSError("can't set 512 block size")
 
        # set to high data rate now that it's initialised
        self.init_spi(baudrate)
 
    def init_card_v1(self):
        for i in range(_CMD_TIMEOUT):
            self.cmd(55, 0, 0)
            if self.cmd(41, 0, 0) == 0:
                # SDSC card, uses byte addressing in read/write/erase commands
                self.cdv = 512
                # print("[SDCard] v1 card")
                return
        raise OSError("timeout waiting for v1 card")
 
    def init_card_v2(self):
        for i in range(_CMD_TIMEOUT):
            time.sleep_ms(50)
            self.cmd(58, 0, 0, 4)
            self.cmd(55, 0, 0)
            if self.cmd(41, 0x40000000, 0) == 0:
                self.cmd(58, 0, 0, -4)  # 4-byte response, negative means keep the first byte
                ocr = self.tokenbuf[0]  # get first byte of response, which is OCR
                if not ocr & 0x40:
                    # SDSC card, uses byte addressing in read/write/erase commands
                    self.cdv = 512
                else:
                    # SDHC/SDXC card, uses block addressing in read/write/erase commands
                    self.cdv = 1
                # print("[SDCard] v2 card")
                return
        raise OSError("timeout waiting for v2 card")
 
    def cmd(self, cmd, arg, crc, final=0, release=True, skip1=False):
        self.cs(0)
 
        # create and send the command
        buf = self.cmdbuf
        buf[0] = 0x40 | cmd
        buf[1] = arg >> 24
        buf[2] = arg >> 16
        buf[3] = arg >> 8
        buf[4] = arg
        buf[5] = crc
        self.spi.write(buf)
 
        if skip1:
            self.spi.readinto(self.tokenbuf, 0xFF)
 
        # wait for the response (response[7] == 0)
        for i in range(_CMD_TIMEOUT):
            self.spi.readinto(self.tokenbuf, 0xFF)
            response = self.tokenbuf[0]
            if not (response & 0x80):
                # this could be a big-endian integer that we are getting here
                # if final<0 then store the first byte to tokenbuf and discard the rest
                if final < 0:
                    self.spi.readinto(self.tokenbuf, 0xFF)
                    final = -1 - final
                for j in range(final):
                    self.spi.write(b"\xff")
                if release:
                    self.cs(1)
                    self.spi.write(b"\xff")
                return response
 
        # timeout
        self.cs(1)
        self.spi.write(b"\xff")
        return -1
 
    def readinto(self, buf):
        self.cs(0)
 
        # read until start byte (0xff)
        for i in range(_CMD_TIMEOUT):
            self.spi.readinto(self.tokenbuf, 0xFF)
            if self.tokenbuf[0] == _TOKEN_DATA:
                break
            time.sleep_ms(1)
        else:
            self.cs(1)
            raise OSError("timeout waiting for response")
 
        # read data
        mv = self.dummybuf_memoryview
        if len(buf) != len(mv):
            mv = mv[: len(buf)]
        self.spi.write_readinto(mv, buf)
 
        # read checksum
        self.spi.write(b"\xff")
        self.spi.write(b"\xff")
 
        self.cs(1)
        self.spi.write(b"\xff")
 
    def write(self, token, buf):
        self.cs(0)
 
        # send: start of block, data, checksum
        self.spi.read(1, token)
        self.spi.write(buf)
        self.spi.write(b"\xff")
        self.spi.write(b"\xff")
 
        # check the response
        if (self.spi.read(1, 0xFF)[0] & 0x1F) != 0x05:
            self.cs(1)
            self.spi.write(b"\xff")
            return
 
        # wait for write to finish
        while self.spi.read(1, 0xFF)[0] == 0:
            pass
 
        self.cs(1)
        self.spi.write(b"\xff")
 
    def write_token(self, token):
        self.cs(0)
        self.spi.read(1, token)
        self.spi.write(b"\xff")
        # wait for write to finish
        while self.spi.read(1, 0xFF)[0] == 0x00:
            pass
 
        self.cs(1)
        self.spi.write(b"\xff")
 
    def readblocks(self, block_num, buf):
        nblocks = len(buf) // 512
        assert nblocks and not len(buf) % 512, "Buffer length is invalid"
        if nblocks == 1:
            # CMD17: set read address for single block
            if self.cmd(17, block_num * self.cdv, 0, release=False) != 0:
                # release the card
                self.cs(1)
                raise OSError(5)  # EIO
            # receive the data and release card
            self.readinto(buf)
        else:
            # CMD18: set read address for multiple blocks
            if self.cmd(18, block_num * self.cdv, 0, release=False) != 0:
                # release the card
                self.cs(1)
                raise OSError(5)  # EIO
            offset = 0
            mv = memoryview(buf)
            while nblocks:
                # receive the data and release card
                self.readinto(mv[offset : offset + 512])
                offset += 512
                nblocks -= 1
            if self.cmd(12, 0, 0xFF, skip1=True):
                raise OSError(5)  # EIO
 
    def writeblocks(self, block_num, buf):
        nblocks, err = divmod(len(buf), 512)
        assert nblocks and not err, "Buffer length is invalid"
        if nblocks == 1:
            # CMD24: set write address for single block
            if self.cmd(24, block_num * self.cdv, 0) != 0:
                raise OSError(5)  # EIO
 
            # send the data
            self.write(_TOKEN_DATA, buf)
        else:
            # CMD25: set write address for first block
            if self.cmd(25, block_num * self.cdv, 0) != 0:
                raise OSError(5)  # EIO
            # send the data
            offset = 0
            mv = memoryview(buf)
            while nblocks:
                self.write(_TOKEN_CMD25, mv[offset : offset + 512])
                offset += 512
                nblocks -= 1
            self.write_token(_TOKEN_STOP_TRAN)
 
    def ioctl(self, op, arg):
        if op == 4:  # get number of blocks
            return self.sectors
        if op == 5:  # get block size in bytes
            return 512

注意,SD 卡需要接 5V 电源

python
import os
from machine import Pin, SoftSPI
from sdcard import SDCard

# 接线说明:
# MISO -> GPTO4
# MOSI -> GPIO5
# SCK -> GPIO6
# CS -> GPIO7
# VCC -> 5V

# 创建 SD SPI 卡对象
sd_spi = SoftSPI(-1, miso=Pin(4), mosi=Pin(5), sck=Pin(6))
# 创建 SD 卡对象
sd = SDCard(sd_spi, Pin(7))

# get root directory and file
print('根目录内容:{}'.format(os.listdir()))

# 创建虚拟文件系统
vfs = os.VfsFat(sd)

# 挂在存储卡到 /sd
os.mount(vfs, '/sd')

print('(挂在目录成功)')
print('根目录内容为:{}'.format(os.listdir()))

os.chdir('sd')
print('(切换到 sd 目录)')
print('SD 存储卡内容:{}'.format(os.listdir()))

操作文件

python
import os
from machine import Pin, SoftSPI
from sdcard import SDCard

sd_spi = SoftSPI(-1, miso=Pin(4), mosi=Pin(5), sck=Pin(6))
sd = SDCard(sd_spi, Pin(7))

vfs = os.VfsFat(sd)
os.mount(vfs, '/sd')

os.chdir('sd')
print('SD Card contains:{}'.format(os.listdir()))

# w 方式写入文件
file = open("hello.txt", "w", encoding='utf-8')
file.write("ESP32-S3-FILE-TEST")
file.close()

local_file = open("hello.txt", "r", encoding='utf-8')
print(local_file.read())

更多文件操作,参考 文件os 模块

关于文件操作,更多的是操作 JSON 字符串。很少自己拼接字符串

注意:mpy