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    External SD Card

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    sd card
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    • robert-hhR Offline
      robert-hh @livius
      last edited by

      @livius And value(1) instead of high().
      That was a confusing change in the API, which broke a lot of code.

      M 1 Reply Last reply Reply Quote 0
      • M Offline
        Manju2391 @robert-hh
        last edited by

        @robert-hh @livius
        I did change the values according to pycom sources but still its not liking it. I'm getting this error
        File "/flash/sd.py", line 9
        File "/flash/lib/sdcard.py", line 54, in_init_
        File "/flash/lib/sdcard.py", line 79, in init_card
        File "/flash/lib/sdcard.py", line 147, in cmd
        Typeerror: extra positional arguments given

        robert-hhR 1 Reply Last reply Reply Quote 0
        • robert-hhR Offline
          robert-hh @Manju2391
          last edited by

          @manju2391 It seems that this library is a little bit outdated. I know that I used this on an esp8266, and it worked. And the version on the micropython.org site seems to be a little bit more recent. (https://github.com/micropython/micropython/tree/master/drivers/sdcard). I can check, but not before the evening, which is in about 8 hours.

          M 1 Reply Last reply Reply Quote 0
          • M Offline
            Manju2391 @robert-hh
            last edited by

            @robert-hh
            Is there any possibility to interface the SD card over shared SPI bus without using any
            libraries? I have been getting my head around the SPI module from last week and I haven't got it yet. Not a problem @robert-hh you can let me know how it goes after testing

            robert-hhR 1 Reply Last reply Reply Quote 0
            • robert-hhR Offline
              robert-hh @Manju2391
              last edited by robert-hh

              @manju2391 I tried that driver, and I got it to the point where it showed some activity. The code is below. The sdcard SPI is connected to:
              P9 (SS), P10(Clk), P11(MOSI) and P12 (MISO). It is started with:

              import sdcard, machine, os
              
              sd = sdcard.SDCard(machine.SPI(0), machine.Pin("P9"))
              os.mount(sd, "/card")
              

              But it is very unstable, runs at low speed only, and data read from the card contains the byte sequence "\x7f\x04" here and there. And sometimes lopy simply crashed. So it's nothing really usable at the moment.
              I tried that with two different SD card adapters. One with embedded bus drivers, which is like the one you have, and one which is simply wiring. The latter runs well when connected to the genuine SD card pins of the xxPy, using the built-in SD card module.

              """
              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 xxPy:
              
                  import machine, sdcard, os
                  sd = sdcard.SDCard(machine.SPI(0), machine.Pin("P9"))
                  os.mount(sd, '/sd2')
                  os.listdir('/sd2')
              
              
              """
              
              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):
                      self.spi = spi
                      self.cs = cs
              
                      self.cmdbuf = bytearray(6)
                      self.dummybuf = bytearray(512)
                      for i in range(512):
                          self.dummybuf[i] = 0xff
                      self.dummybuf_memoryview = memoryview(self.dummybuf)
              
                      # initialise the card
                      self.init_card()
              
                  def init_spi(self, baudrate):
                      master = self.spi.MASTER
                      self.spi.init(master, baudrate=baudrate, phase=0, polarity=0)
              
                  def init_card(self):
                      # 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:
                          raise OSError("SD card CSD format not supported")
                      self.sectors = ((csd[8] << 8 | csd[9]) + 1) * 2014
                      #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(100000)
                      #self.init_spi(40000000)
              
                  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):
                      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)
              
                      # wait for the response (response[7] == 0)
                      for i in range(_CMD_TIMEOUT):
                          response = self.spi.read(1, write=0xff)[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 cmd_nodata(self, cmd):
                      self.spi.write(cmd)
                      self.spi.read(1, write=0xff) # ignore stuff byte
                      for _ in range(_CMD_TIMEOUT):
                          if self.spi.read(1, write=0xff)[0] == 0xff:
                              self.cs(1)
                              self.spi.write(b'\xff')
                              return 0    # OK
                      self.cs(1)
                      self.spi.write(b'\xff')
                      return 1 # timeout
              
                  def readinto(self, buf):
                      self.cs(0)
              
                      # read until start byte (0xff)
                      while self.spi.read(1, write=0xff)[0] != 0xfe:
                          pass
              
                      # read data
                      mv = self.dummybuf_memoryview[: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 count(self):
                      return self.sectors
              
                  def readblocks(self, block_num, buf):
                      nblocks, err = divmod(len(buf), 512)
                      assert nblocks and not err, 'Buffer length is invalid'
                      if nblocks == 1:
                          # CMD17: set read address for single block
                          if self.cmd(17, block_num * self.cdv, 0) != 0:
                              return 1
                          # receive the data
                          self.readinto(buf)
                      else:
                          # CMD18: set read address for multiple blocks
                          if self.cmd(18, block_num * self.cdv, 0) != 0:
                              return 1
                          offset = 0
                          mv = memoryview(buf)
                          while nblocks:
                              self.readinto(mv[offset : offset + 512])
                              offset += 512
                              nblocks -= 1
                          return self.cmd_nodata(b'\x0c') # cmd 12
                      return 0
              
                  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:
                              return 1
              
                          # 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:
                              return 1
                          # 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)
                      return 0
              
              M N 2 Replies Last reply Reply Quote 1
              • M Offline
                Manju2391 @robert-hh
                last edited by

                @robert-hh
                Thanks for your reply robert and I'll try working on it today and will post if anything crashes up and I have one more doubt regarding the WLAN access point. I have created an access point and I want to connect to my AP whenever the boot.py loads up. I can connect as a station but not as an access point i tried using this syntax but whenever it boots up it's looking for wlan AP but couldn't find it and goes to deep sleep mode. My network is up and it runs when I run it externally but not during boot up.

                from network import WLAN

                wlan.init(mode=WLAN.STA_AP,ssid='AP')
                wlan.init(ssid='AP',auth=(WLAN.WPA2,'xxxx'))
                print(wlan.ifconfig())

                Is the above syntax right?

                robert-hhR 1 Reply Last reply Reply Quote 0
                • robert-hhR Offline
                  robert-hh @Manju2391
                  last edited by

                  @manju2391 About WLAN: It could look like:

                  from network import WLAN
                  
                  wlan = WLAN(mode=WLAN.STA_AP)
                  wlan.connect(ssid='AP',auth=(WLAN.WPA2, 'xxxx'))
                  # from here on it's optional. It just takes a few moments to connect
                  for _ in range (200):
                      if wlan.isconnected():
                          print(wlan.ifconfig())
                          break
                      else:
                          time.sleep_ms(50)
                  else:
                      print("Could not connect")
                  
                  M 1 Reply Last reply Reply Quote 0
                  • M Offline
                    Manju2391 @robert-hh
                    last edited by

                    @robert-hh

                    I tried using SPI bus it is very slow. I had designed the pcb with spi pins but looks like it is not best so I’m just using the SDIO pins and changed the pcb. About the WLAN when I define wlan initially it is asking me for ap ssid at first I get an error saying ap ssid not given. I get the IP address when run locally and it connects to FileZilla but when it boots for the STA_AP it doesn’t print the IP address nor it connects to WLAN. It will be in idle state. I don’t know why it’s not connecting. I’m wondering should we create a station first and then an AP?

                    1 Reply Last reply Reply Quote 0
                    • N Offline
                      nathanh @robert-hh
                      last edited by nathanh

                      @robert-hh said in External SD Card:

                      """
                      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 xxPy:
                      
                          import machine, sdcard, os
                          sd = sdcard.SDCard(machine.SPI(0), machine.Pin("P9"))
                          os.mount(sd, '/sd2')
                          os.listdir('/sd2')
                      
                      
                      """
                      
                      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):
                              self.spi = spi
                              self.cs = cs
                      
                              self.cmdbuf = bytearray(6)
                              self.dummybuf = bytearray(512)
                              for i in range(512):
                                  self.dummybuf[i] = 0xff
                              self.dummybuf_memoryview = memoryview(self.dummybuf)
                      
                              # initialise the card
                              self.init_card()
                      
                          def init_spi(self, baudrate):
                              master = self.spi.MASTER
                              self.spi.init(master, baudrate=baudrate, phase=0, polarity=0)
                      
                          def init_card(self):
                              # 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:
                                  raise OSError("SD card CSD format not supported")
                              self.sectors = ((csd[8] << 8 | csd[9]) + 1) * 2014
                              #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(100000)
                              #self.init_spi(40000000)
                      
                          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):
                              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)
                      
                              # wait for the response (response[7] == 0)
                              for i in range(_CMD_TIMEOUT):
                                  response = self.spi.read(1, write=0xff)[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 cmd_nodata(self, cmd):
                              self.spi.write(cmd)
                              self.spi.read(1, write=0xff) # ignore stuff byte
                              for _ in range(_CMD_TIMEOUT):
                                  if self.spi.read(1, write=0xff)[0] == 0xff:
                                      self.cs(1)
                                      self.spi.write(b'\xff')
                                      return 0    # OK
                              self.cs(1)
                              self.spi.write(b'\xff')
                              return 1 # timeout
                      
                          def readinto(self, buf):
                              self.cs(0)
                      
                              # read until start byte (0xff)
                              while self.spi.read(1, write=0xff)[0] != 0xfe:
                                  pass
                      
                              # read data
                              mv = self.dummybuf_memoryview[: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 count(self):
                              return self.sectors
                      
                          def readblocks(self, block_num, buf):
                              nblocks, err = divmod(len(buf), 512)
                              assert nblocks and not err, 'Buffer length is invalid'
                              if nblocks == 1:
                                  # CMD17: set read address for single block
                                  if self.cmd(17, block_num * self.cdv, 0) != 0:
                                      return 1
                                  # receive the data
                                  self.readinto(buf)
                              else:
                                  # CMD18: set read address for multiple blocks
                                  if self.cmd(18, block_num * self.cdv, 0) != 0:
                                      return 1
                                  offset = 0
                                  mv = memoryview(buf)
                                  while nblocks:
                                      self.readinto(mv[offset : offset + 512])
                                      offset += 512
                                      nblocks -= 1
                                  return self.cmd_nodata(b'\x0c') # cmd 12
                              return 0
                      
                          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:
                                      return 1
                      
                                  # 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:
                                      return 1
                                  # 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)
                              return 0
                      

                      I know this is a bit old but I just got an SD card module (https://www.sparkfun.com/products/13743) and was trying to get it working with my FiPy. I was running into a lot of issues but was able to make some headway using the library you pasted @robert-hh and thought I would share my results in case other people wanted to get it working.

                      However, I did have some errors with the library and had to make the following changes:

                      • The pins you used are not the default pins for the SPI init call. So I created my own SPI instance with the pin allocation you had in the post (since I already had them like that) and passed that instance into the SDCard constructor rather than machine.SPI(0). I also removed the additional spi init calls.

                      • I had to set the SPI baudrate to 1000000 instead of 100000

                      • I had to declare the CS pin as an instance outside of the library and pass it in similar to the SPI above.

                      • The command to check idle state at the start of the library self.cmd(0, 0, 0x95) would never return a value of 1. I don't know where the reference of these commands were but testing the other commands manually all returned values as expected. So I commented out the entire block that checks for the SD card or raises the 'no SD card' error. I found that I still need to run this command regardless, I get the same set of (4?) different values that repeat each time it is called. They never equal 1 but I let the code continue and command out the error block. Not calling the 0x95 command will not allow the next set of command to work correctly.

                      Doing the above I have gotten my external SD card board working fine with the FiPy. For reference below are my library and how I call it.

                      """
                      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 xxPy:
                      
                          import machine, sdcard, os
                          sd = sdcard.SDCard(machine.SPI(0), machine.Pin("P9"))
                          os.mount(sd, '/sd2')
                          os.listdir('/sd2')
                      
                      
                      """
                      
                      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):
                              self.spi = spi
                              self.cs = cs
                      
                              self.cmdbuf = bytearray(6)
                              self.dummybuf = bytearray(512)
                              for i in range(512):
                                  self.dummybuf[i] = 0xff
                              self.dummybuf_memoryview = memoryview(self.dummybuf)
                      
                              # initialise the card
                              self.init_card()
                      
                          def init_spi(self, baudrate):
                              master = self.spi.MASTER
                              self.spi.init(master, baudrate=baudrate, phase=0, polarity=0)
                      
                          def init_card(self):
                              # init CS pin        
                              #self.cs.init(self.cs.OUT, value=0)
                      
                              # 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:
                                  raise OSError("SD card CSD format not supported")
                              self.sectors = ((csd[8] << 8 | csd[9]) + 1) * 2014
                              #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(100000)
                              #self.init_spi(40000000)
                      
                          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):
                              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)
                      
                              # wait for the response (response[7] == 0)
                              for i in range(_CMD_TIMEOUT):
                                  response = self.spi.read(1, write=0xff)[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 cmd_nodata(self, cmd):
                              self.spi.write(cmd)
                              self.spi.read(1, write=0xff) # ignore stuff byte
                              for _ in range(_CMD_TIMEOUT):
                                  if self.spi.read(1, write=0xff)[0] == 0xff:
                                      self.cs(1)
                                      self.spi.write(b'\xff')
                                      return 0    # OK
                              self.cs(1)
                              self.spi.write(b'\xff')
                              return 1 # timeout
                      
                          def readinto(self, buf):
                              self.cs(0)
                      
                              # read until start byte (0xff)
                              while self.spi.read(1, write=0xff)[0] != 0xfe:
                                  pass
                      
                              # read data
                              mv = self.dummybuf_memoryview[: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 count(self):
                              return self.sectors
                      
                          def readblocks(self, block_num, buf):
                              nblocks, err = divmod(len(buf), 512)
                              assert nblocks and not err, 'Buffer length is invalid'
                              if nblocks == 1:
                                  # CMD17: set read address for single block
                                  if self.cmd(17, block_num * self.cdv, 0) != 0:
                                      return 1
                                  # receive the data
                                  self.readinto(buf)
                              else:
                                  # CMD18: set read address for multiple blocks
                                  if self.cmd(18, block_num * self.cdv, 0) != 0:
                                      return 1
                                  offset = 0
                                  mv = memoryview(buf)
                                  while nblocks:
                                      self.readinto(mv[offset : offset + 512])
                                      offset += 512
                                      nblocks -= 1
                                  return self.cmd_nodata(b'\x0c') # cmd 12
                              return 0
                      
                          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:
                                      return 1
                      
                                  # 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:
                                      return 1
                                  # 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)
                              return 0
                      
                      from machine import SPI
                      from machine import Pin
                      import machine, sdcard, os
                      spi = SPI(0, mode=SPI.MASTER, baudrate=1000000, polarity=0, phase=0, pins=('P10','P11','P12'))
                      cs = Pin('P9', Pin.OUT)
                      sd = sdcard.SDCard(spi, cs)
                      os.mount(sd, "/card")
                      

                      I could probably tidy up the library to initialise the SPI and CS properly internally but this got me going at least.

                      1 Reply Last reply Reply Quote 1
                      • E Offline
                        Edward Dimmack @jmarcelino
                        last edited by

                        @jmarcelino Would this wiring work?

                        0_1549934788017_aba064d6-d4e9-4383-86bc-da3e0aafb20a-image.png

                        robert-hhR 1 Reply Last reply Reply Quote 0
                        • robert-hhR Offline
                          robert-hh @Edward Dimmack
                          last edited by

                          @edward-dimmack That should work. I'm using this wiring on my homebrew interface boards.

                          1 Reply Last reply Reply Quote 1

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