Micropython学习交流群 学习QQ群:786510434 提供多种固件下载和学习交流。

Micropython-扇贝物联 QQ群:31324057 扇贝物联是一个让你与智能设备沟通更方便的物联网云平台

Micropython学习交流群 学习QQ群:468985481 学习交流ESP8266、ESP32、ESP8285、wifi模块开发交流、物联网。

Micropython老哥俩的IT农场分享QQ群:929132891 为喜欢科创制作的小白们分享一些自制的计算机软硬件免费公益课程,由两位多年从事IT研发的中年大叔发起。

Micropython ESP频道

micropython里面外接tf(sd)卡读取模块


micropython里面外接tf(sd)卡读取模块

一般板子容量有限,8M都算很大了,如果想扩容咋办,那就自己加sd卡,其实micropython固件自带了machine.SDCard,但是我没测出来,于是直接在GAY站上搜了一个,测试成功,一个sd卡扩展模块才1.6元,问题在于一般其实没有那么大的内存需求,加了扩展模块需要占用一个spi口,外加CS,一共用掉4个pin
sd.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.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 | csd[7] << 2 | (csd[8] & 0b11000000) << 4
            c_size_mult = ((csd[9] & 0b11) << 1) | csd[10] >> 7
            self.sectors = (c_size + 1) * (2 ** (c_size_mult + 2))
        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:
                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)
                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
                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

test.py

import machine, sd, os
from machine import SPI,Pin
spitf=SPI(baudrate=2000000, sck=Pin(18), mosi=Pin(19),miso=Pin(23))
tf = sd.SDCard(spitf,Pin(5))
os.mount(tf, '/sd')
os.listdir('/')

然后直接在thonny里面发现目录里多了一个sd文件夹,他就是我们亲爱的sd卡了,亲测上传下载文件都正常。


来源:https://blog.csdn.net/jd3096/article/details/123209490



推荐分享
图文皆来源于网络,内容仅做公益性分享,版权归原作者所有,如有侵权请告知删除!
 

Copyright © 2014 ESP56.com All Rights Reserved

执行时间: 0.0086238384246826 seconds