sdremote.py

import machine
import os
from micropython import const
import time
import network
import socket

_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):
            time.sleep_ms(50)
            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):
        # workaround for shared bus, required for (at least) some Kingston
        # devices, ensure MOSI is high before starting transaction
        self.spi.write(b"\xff")

        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):
        # workaround for shared bus, required for (at least) some Kingston
        # devices, ensure MOSI is high before starting transaction
        self.spi.write(b"\xff")

        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


# gpio12 - MISO
# gpio13 - MOSI
# gpio14 - SCK
# gpio4,5 - CS
CS_PIN = 4
MISO_PIN = 12
MOSI_PIN = 13
SCLK_PIN = 14
CS_SENSE_PIN = 5
LED_PIN = 2


class Main:
    def __init__(self):
        self.sd = None
        self.server_socket = None

    def led_on(self):
        p = machine.Pin(LED_PIN)
        p.on()

    def led_off(slef):
        p = machine.Pin(LED_PIN)
        p.off()

    def take_bus_control(self):
        self.led_on()
        # 4. CLK_XTAL
        # 5. CLK_RTC
        # 12. SPI_MISO
        # 13. SPI_MOSI
        # 14. SPI_CLK
        # 15. SPI_SS
        # UART RX/TX on pins 1 - 3, HSPI for pins 12-15 and CLK functions for pins 0, 4 and 5.
        # enum {
        #     PIN_MODE_IN = 0,
        #     PIN_MODE_OUT,
        #     PIN_MODE_OPEN_DRAIN,
        #     PIN_MODE_ALT,
        #     PIN_MODE_SKIP,
        #     PIN_MODE_IT_RISING,
        #     PIN_MODE_IT_FALLING,
        #     PIN_MODE_IT_BOTH,
        # };
        machine.Pin(MISO_PIN).mode(machine.Pin.OPEN_DRAIN)
        machine.Pin(MOSI_PIN).mode(machine.Pin.OPEN_DRAIN)
        machine.Pin(SCLK_PIN).mode(machine.Pin.OPEN_DRAIN)
        machine.Pin(CS_PIN).mode(machine.Pin.OUT)

    def relinquish_bus_control(self):
        machine.Pin(MISO_PIN).mode(machine.Pin.IN)
        machine.Pin(MOSI_PIN).mode(machine.Pin.IN)
        machine.Pin(SCLK_PIN).mode(machine.Pin.IN)
        machine.Pin(CS_PIN).mode(machine.Pin.IN)
        self.led_off()

    def connect_wifi(self):
        wifi = network.WLAN(network.STA_IF)
        wifi.active(True)
        wifi.connect('YourNetworkSSID', 'YourNetworkPassword')

        while not wifi.isconnected():
            time.sleep(1)

        print('Connected to Wi-Fi:', wifi.ifconfig())

    def parser_header(self, data: bytes):
        out = {}
        lines = data.split(b'\r\n')
        for line in lines[1:]:
            key, value = line.split(b': ', 1)
            out[key.decode().lower()] = value.decode()

        firstdata = lines[0].decode().split(' ')
        method = firstdata[0]
        url = firstdata[1]
        urlparams = ''
        if '?' in url:
            url, urlparams = url.split('?', 1)

        return method, url, urlparams, out

    def handle_start(self) -> bytes:
        self.take_bus_control()
        self.sd = SDCard(
            spi=machine.SPI(sck=machine.Pin(SCLK_PIN), mosi=machine.Pin(MOSI_PIN), miso=machine.Pin(MISO_PIN)),
            cs=machine.Pin(CS_PIN),
        )
        return b'OK'

    def handle_stop(self) -> bytes:
        self.relinquish_bus_control()
        self.sd = None
        return b'OK'

    def handle_size(self) -> bytes:
        if not self.sd:
            return b'error not sdcard'
        return f'sectors={self.sd.sectors}&blocksize={self.sd.cdv}'.encode()

    def handle_read(self, sectorid: int) -> bytes:
        if not self.sd:
            return b'error not sdcard'
        buf = bytes(bytearray([0]*512))
        self.sd.readblocks(sectorid, buf)
        return buf

    def handle_write(self, sectorid: int, buf: bytes) -> bytes:
        if not self.sd:
            return b'error not sdcard'
        if len(buf) != 512:
            return b'error size not match 512'
        self.sd.writeblocks(sectorid, buf)
        return b'OK'

    def handle_data(self, client):
        data = client.recv(1024)
        headerdata, clientdata = data.split(b'\r\n\r\n', 1)
        method, url, urlparams, header = self.parser_header(headerdata)

        payload = b''
        if method == 'POST' and header.get('content-length'):
            datalen = int(header.get('content-length')) - len(clientdata)
            payload = clientdata
            if datalen > 0:
                payload += client.recv(datalen)

        response = b''
        if method == 'GET' and url == '/start':
            response = self.handle_start()
        if method == 'GET' and url == '/stop':
            response = self.handle_stop()
        if method == 'GET' and url == '/size':
            response = self.handle_size()
        if method == 'GET' and url == '/read':
            sectorid = int(urlparams)
            response = self.handle_read(sectorid)
        if method == 'POST' and url == '/write':
            sectorid = int(urlparams)
            response = self.handle_write(sectorid, payload)

        client.send(b"HTTP/1.0 200 OK\r\nContent-Length: " + str(len(response)).encode() + b"\r\n\r\n")
        client.send(response)

    def start_server(self):
        self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        host = '0.0.0.0'
        port = 8080
        self.server_socket.bind((host, port))

        self.server_socket.listen(5)
        print("Server listening on port", port)

        while True:
            client_socket, client_address = self.server_socket.accept()
            print("Accepted connection from", client_address)
            self.handle_data(client_socket)
            client_socket.close()

    def run(self):
        self.relinquish_bus_control()
        self.connect_wifi()
        self.start_server()


Main().run()