removed dos linebreaks

git-svn-id: https://svn.spreadspace.org/avr/trunk@131 aa12f405-d877-488e-9caf-2d797e2a1cc7

1 files changed, 478 insertions, 478 deletions

diff --git a/usb-i2c-sl018/tuer-rfid.c b/usb-i2c-sl018/tuer-rfid.c
index 3b6b0da..92dc97d 100644
--- a/usb-i2c-sl018/tuer-rfid.c
+++ b/usb-i2c-sl018/tuer-rfid.c
@@ -1,478 +1,478 @@
-/*

- *  spreadspace avr utils

- *

- *

- *  Copyright (C) 2013 Christian Pointner <equinox@spreadspace.org>

- *                     Othmar Gsenger <otti@wirdorange.org>

- *

- *  This file is part of spreadspace avr utils.

- *

- *  spreadspace avr utils is free software: you can redistribute it and/or modify

- *  it under the terms of the GNU General Public License as published by

- *  the Free Software Foundation, either version 3 of the License, or

- *  any later version.

- *

- *  spreadspace avr utils is distributed in the hope that it will be useful,

- *  but WITHOUT ANY WARRANTY; without even the implied warranty of

- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- *  GNU General Public License for more details.

- *

- *  You should have received a copy of the GNU General Public License

- *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include <avr/io.h>

-#include <avr/wdt.h>

-#include <avr/interrupt.h>

-#include <avr/power.h>

-

-#include <stdio.h>

-#include <string.h>

-

-#include "util.h"

-#include "led.h"

-

-#include "heartbeat.h"

-#include "stepper.h"

-#include "ledmatrix.h"

-

-#include "LUFA/Drivers/Peripheral/TWI.h"

-#include "LUFA/Drivers/Peripheral/Serial.h"

-#include "LUFA/Drivers/Misc/RingBuffer.h"

-

-#include <avr/eeprom.h>

-#define EEPROM_SIZE 1024

-typedef uint8_t keyslot_t[8];

-keyslot_t EEMEM keystore[EEPROM_SIZE/sizeof(keyslot_t)];

-

-

-const char* SL018_cmd_tostring(const uint8_t cmd) 

-{

-  switch(cmd) {

-  case 0x01: return "Select Mifare card";

-  case 0x02: return "Login to a sector";

-  case 0x03: return "Read a data block";

-  case 0x04: return "Write a data block";

-  case 0x05: return "Read a value block";

-  case 0x06: return "Initialize a value block";

-  case 0x07: return "Write master key";

-  case 0x08: return "Increment value";

-  case 0x09: return "Decrement value";

-  case 0x0A: return "Copy value";

-  case 0x10: return "Read a data page";

-  case 0x11: return "Write a data page";

-  case 0x40: return "Control the red led";

-  case 0xF0: return "Get firmware version";

-  case 0xFF: return "Reset";

-  default: return "unknown";

-  }

-}

-

-const char* SL018_status_tostring(const uint8_t status) 

-{

-  switch(status) {

-  case 0x0: return "Operation succeed";

-  case 0x1: return "No tag";

-  case 0x2: return "Login succeed";

-  case 0x3: return "Login fail";

-  case 0x4: return "Read fail";

-  case 0x5: return "Write fail";

-  case 0x6: return "Unable to read after write";

-  case 0xA: return "Collision occur";

-  case 0xC: return "Load key fail";

-  case 0xD: return "Not authenticate";

-  case 0xE: return "Not a value block";

-  default: return "unknown";

-  }

-}

-

-const char* SL018_tagtype_tostring(const uint8_t type) 

-{

-  switch(type) {

-  case 0x1: return "Mifare 1k, 4 byte UID";

-  case 0x2: return "Mifare 1k, 7 byte UID";

-  case 0x3: return "Mifare Ultralight or NATG203, 7 byte UID";

-  case 0x4: return "Mifare 4k, 4 byte UID";

-  case 0x5: return "Mifare 4k, 7 byte UID";

-  case 0x6: return "Mifare DesFire, 7 byte UID";

-  default: return "unknown";

-  }

-}

-

-uint8_t SL018_tagtype_to_uidlen(const uint8_t type) 

-{

-  switch(type) {

-  case 0x1:

-  case 0x4: return 4;

-  case 0x2:

-  case 0x3:

-  case 0x5:

-  case 0x6: return 7;

-  default: return 0;

-  }

-}

-

-const uint8_t SL018_CMD_ComSelectCard[]         = {1,0x01};

-const uint8_t SL018_CMD_ComRedLedOn[]           = {2,0x40,1};

-const uint8_t SL018_CMD_ComRedLedOff[]          = {2,0x40,0};

-const uint8_t SL018_CMD_ComGetFirmwareVersion[] = {1,0xF0};

-const uint8_t SL018_CMD_ComReset[]              = {1,0xFF};

-

-uint8_t twi_recv_buf[256];

-typedef struct __attribute__((__packed__))

-{

-  uint8_t len;

-  uint8_t command;

-  uint8_t status;

-  uint8_t data[sizeof(twi_recv_buf)-3];

-} sl018_message_t;

-

-sl018_message_t* twi_recv_msg = (sl018_message_t *)&twi_recv_buf;

-

-#define SL018_TWI_ADDR  0xA0

-#define SL018_TAG_STA_PIN PIND

-#define SL018_TAG_STA_BIT 7

-#define CARD_PRESENT (!((SL018_TAG_STA_PIN >> SL018_TAG_STA_BIT) & 1))

-uint8_t card_status = 0;

-

-

-

-FILE usb_stream;

-FILE serial_stream;

-FILE * stdio = &serial_stream;

-

-/*

-             LUFA Library

-     Copyright (C) Dean Camera, 2012.

-

-  dean [at] fourwalledcubicle [dot] com

-           www.lufa-lib.org

-*/

-

-

-#include <LUFA/Drivers/USB/USB.h>

-#include "lufa-descriptor-usbserial.h"

-

-USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =

-  {

-    .Config =

-      {

-        .ControlInterfaceNumber         = 0,

-

-        .DataINEndpointNumber           = CDC_TX_EPNUM,

-        .DataINEndpointSize             = CDC_TXRX_EPSIZE,

-        .DataINEndpointDoubleBank       = false,

-

-        .DataOUTEndpointNumber          = CDC_RX_EPNUM,

-        .DataOUTEndpointSize            = CDC_TXRX_EPSIZE,

-        .DataOUTEndpointDoubleBank      = false,

-

-        .NotificationEndpointNumber     = CDC_NOTIFICATION_EPNUM,

-        .NotificationEndpointSize       = CDC_NOTIFICATION_EPSIZE,

-        .NotificationEndpointDoubleBank = false,

-      },

-  };

-

-void EVENT_USB_Device_ConfigurationChanged(void)

-{

-  CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);

-}

-

-void EVENT_USB_Device_ControlRequest(void)

-{

-  CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);

-}

-

-void EVENT_CDC_Device_ControLineStateChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo)	

-{

-  if(CDCInterfaceInfo->State.ControlLineStates.HostToDevice & CDC_CONTROL_LINE_OUT_DTR)

-    stdio = &usb_stream;

-  else

-    stdio = &serial_stream;

-}

-

-void EVENT_USB_Device_Disconnect(void)

-{

-  stdio = &serial_stream;

-}

-/* end LUFA CDC-ACM specific definitions*/

-

-

-

-int16_t stdio_bytes_received(void)

-{

-  if(stdio == &usb_stream)

-    return CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface);

-  else

-    return (int16_t)Serial_IsCharReceived();

-}

-

-uint8_t sl018_cmd_raw(const uint8_t* twi_send_buf, bool wait_for_answer)

-{

-  uint8_t pos = 0;

-

-  if (TWI_StartTransmission(SL018_TWI_ADDR | TWI_ADDRESS_WRITE,10) == TWI_ERROR_NoError) {

-    for(pos=0; pos<=twi_send_buf[0]; pos++) {

-      if( ! TWI_SendByte(twi_send_buf[pos])) {

-        TWI_StopTransmission();

-        return 1;

-      }

-    }

-    TWI_StopTransmission();

-  } else 

-    return 1;

-

-  if(!wait_for_answer) return 0;

-

-  memset(twi_recv_buf, 0, sizeof(twi_recv_buf));

-  _delay_ms(50);

-

-  if (TWI_StartTransmission(SL018_TWI_ADDR | TWI_ADDRESS_READ,10) == TWI_ERROR_NoError) {

-    TWI_ReceiveByte(twi_recv_buf, 0);

-    for(pos=1; pos<=twi_recv_buf[0]; pos++) {

-      if (! TWI_ReceiveByte(&twi_recv_buf[pos], (pos == twi_recv_buf[0]) ? 1:0 ) ) {

-        TWI_StopTransmission();

-        return 1;

-      }

-    }

-    TWI_StopTransmission();

-  } else

-    return 1;

-

-  return 0;

-}

-

-uint8_t sl018_reset(void)

-{

-  if(sl018_cmd_raw(SL018_CMD_ComReset, 0)) {

-    fprintf(stdio, "I2C error\n\r");

-    return 1;

-  }

-  return 0;

-}

-

-uint8_t sl018_cmd(const uint8_t* twi_send_buf)

-{

-  if(sl018_cmd_raw(twi_send_buf, 1)) {

-    fprintf(stdio, "I2C error\n\r");

-    return 1;

-  } else {

-    if(twi_recv_msg->len < 2) {

-      fprintf(stdio,"SL018 Cmd,Error: short message received\n\r");

-      return 1;

-    }

-    if(twi_recv_msg->status) {

-      fprintf(stdio,"SL018 Cmd,Error: '%s','%s'\n\r",SL018_cmd_tostring(twi_recv_msg->command),SL018_status_tostring(twi_recv_msg->status));

-      return 1;

-    }

-    sl018_message_t * twi_send_msg = (sl018_message_t *)twi_send_buf;

-    if(twi_send_msg->command != twi_recv_msg->command) {

-      fprintf(stdio,"SL018 Cmd,Error: mismatch of sent and received command code: %02X,%02X\n\r",twi_send_msg->command,twi_recv_msg->command);

-    }

-  }

-  return 0;

-}

-

-

-

-void flash_keystore_from_stdio(void)

-{

-  keyslot_t ks;

-  uint8_t byte_pos=0;

-  fprintf(stdio,"Flashing keys:\n\r");

-  fflush(stdio);

-  for(uint8_t ks_pos=0;ks_pos<EEPROM_SIZE/sizeof(ks);) {

-    CDC_Device_USBTask(&VirtualSerial_CDC_Interface);

-    USB_USBTask();

-

-    int16_t bytes_received = stdio_bytes_received();

-    while(bytes_received > 0) {

-      ks[byte_pos++]=fgetc(stdio);

-      bytes_received--;

-      if (byte_pos == sizeof(ks)) {

-        byte_pos=0;

-        eeprom_update_block(&ks,&keystore[ks_pos],sizeof(ks));

-        ks_pos++;

-        fputc('.', stdio);

-        fflush(stdio);

-        led_toggle();

-      }

-    }

-  }

-  fprintf(stdio,"\n");

-  fputc(0, stdio);

-  led_off();

-}

-

-void dump_keystore_to_stdio(void)

-{

-  keyslot_t ks;

-  for(uint8_t ks_pos=0;ks_pos<EEPROM_SIZE/sizeof(ks);ks_pos++) {

-    eeprom_read_block(&ks,&keystore[ks_pos],sizeof(ks));

-    for (uint8_t i=0; i< sizeof(ks); i++)

-      fprintf(stdio,"%02X",ks[i]);

-    fprintf(stdio,"\n\r");

-  }

-}

-

-void handle_stdio(uint8_t cmd)

-{  

-  switch(cmd) {

-    case 'r': 

-             reset2bootloader(); 

-             break;

-    case 'R': 

-             if(!sl018_reset())

-               fprintf(stdio, "ok\n\r");

-             break;

-    case 'f': //get cardreader firmware version

-             if(!sl018_cmd(SL018_CMD_ComGetFirmwareVersion)) {

-               twi_recv_msg->data[sizeof(twi_recv_msg->data) - 1] = 0;

-               fprintf(stdio, "%s\n\r",twi_recv_msg->data);

-             }

-             break;

-    case 'e': //flash eeprom

-             flash_keystore_from_stdio();

-             break;

-    case 'd': //dump eeprom - this breaks security!

-             dump_keystore_to_stdio();

-             break;

-    case 'o': 

-             if(start_stepper(dir_open))

-               fprintf(stdio, "ok\n\r");

-             else

-               fprintf(stdio, "error: already in progress\n\r");

-             break;

-    case 'c': 

-             if(start_stepper(dir_close))

-               fprintf(stdio, "ok\n\r");

-             else

-               fprintf(stdio, "error: already in progress\n\r");

-             break;

-    case '0': ledmatrix(off); break;

-    case '1': ledmatrix(red); break;

-    case '2': ledmatrix(red_moving); break;

-    case '3': ledmatrix(red_blink); break;

-    case '4': ledmatrix(green); break;

-    case '5': ledmatrix(green_moving); break;

-    case '6': ledmatrix(green_blink); break;

-    case '7': ledmatrix(rg_moving); break;

-    case '8': ledmatrix(rg_blink); break;

-    default: fprintf(stdio, "error, unknown command %02X '%c'\n\r",cmd, cmd); return;

-  }

-}

-

-

-

-/* this generates a Fletcher8 checksum  */

-/* code from: http://stackoverflow.com/questions/13491700/8-bit-fletcher-checksum-of-16-byte-data */

-uint8_t generate_csum(uint8_t* data)

-{

-  uint16_t sum1 = 0xf, sum2 = 0xf, len = sizeof(keyslot_t) - 1;

-  do { sum2 += ( sum1 += *data++ ); } while (--len);

-  return sum2<<4 | sum1;

-}

-

-uint8_t compare_keyslots(const keyslot_t a, const keyslot_t b)

-{

-  uint8_t tmp=0;

-      // constant time compare

-  for(uint8_t i=0; i<sizeof(keyslot_t); ++i)

-    tmp |= a[i] ^ b[i];

-  return tmp;

-}

-

-bool check_card(const uint8_t * uid, uint8_t uid_len)

-{

-  keyslot_t card, ks;

-  memset(card, 0, sizeof(card));

-  for (uint8_t pos=0; pos<uid_len; pos++)

-    card[pos]=uid[uid_len-pos-1];

-  card[sizeof(keyslot_t)-1]=generate_csum(card);

-  bool valid=0;

-  for(uint8_t ks_pos=0;ks_pos<(EEPROM_SIZE/sizeof(ks));ks_pos++) {

-    eeprom_read_block(&ks,&keystore[ks_pos],sizeof(ks));

-    if(!compare_keyslots(card, ks)) {

-      valid=1;

-      // break;  // this would break security (not constant time)

-    }

-  }

-  return valid;

-}

-

-void handle_card(void)

-{

-  fprintf(stdio, "CARD IN: ");

-  if(!sl018_cmd(SL018_CMD_ComSelectCard))

-  {

-    uint8_t uid_len = twi_recv_msg->len - sizeof(twi_recv_msg->command) - sizeof(twi_recv_msg->status) - 1;

-    if(uid_len == 255 || uid_len > sizeof(keyslot_t) - 1) {

-      fprintf(stdio," received UID length (%d) is to big for keystore \n\r", uid_len);

-      return;

-    }

-    uint8_t type = twi_recv_msg->data[uid_len];

-    uint8_t expected_uid_len = SL018_tagtype_to_uidlen(type);

-    if(expected_uid_len != uid_len) {

-      fprintf(stdio," Invalid uid length (%d) for tag type: %s\n\r", uid_len, SL018_tagtype_tostring(type));

-      return;

-    }    

-

-    for (uint8_t pos=0; pos<uid_len; pos++)

-      fprintf(stdio,"%02X",twi_recv_msg->data[uid_len-pos-1]);

-    fprintf(stdio, ", %s\n\r", SL018_tagtype_tostring(type));

-

-    if (0 < type && type < 7) {

-      if(check_card(twi_recv_msg->data,uid_len)) {

-        sl018_cmd(SL018_CMD_ComRedLedOn);

-        fprintf(stdio,"Card allowed - opening/closing door\n\r"); // TODO: open/close door!

-        _delay_ms(255);

-        sl018_cmd(SL018_CMD_ComRedLedOff);

-      } else {

-        fprintf(stdio,"Card not found in Database\n\r");

-      }

-    } else {

-      fprintf(stdio,"Ignoring unknown card type %02x\n\r",type);

-    }

-  }  

-}

-

-

-

-int main(void)

-{

-  MCUSR &= ~(1 << WDRF);

-  wdt_disable();

-

-  cpu_init();

-  led_init();

-  USB_Init();

-  TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 200000));

-  Serial_Init(115200,false);

-  Serial_CreateStream(&serial_stream);

-  CDC_Device_CreateStream(&VirtualSerial_CDC_Interface,&usb_stream);

-

-  sei();  

-

-  init_heartbeat();

-  init_stepper();

-  init_ledmatrix();

-

-  sl018_reset();

-

-  for(;;) {

-    CDC_Device_USBTask(&VirtualSerial_CDC_Interface);

-    USB_USBTask();

-

-    int16_t bytes_received = stdio_bytes_received();

-    if(bytes_received > 0)

-      handle_stdio(fgetc(stdio));

-

-    if(CARD_PRESENT != card_status) {

-      card_status = CARD_PRESENT;

-      if(card_status)

-        handle_card();

-    }

-

-    handle_heartbeat();

-  }

-}

+/*
+ *  spreadspace avr utils
+ *
+ *
+ *  Copyright (C) 2013 Christian Pointner <equinox@spreadspace.org>
+ *                     Othmar Gsenger <otti@wirdorange.org>
+ *
+ *  This file is part of spreadspace avr utils.
+ *
+ *  spreadspace avr utils is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  spreadspace avr utils is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <avr/io.h>
+#include <avr/wdt.h>
+#include <avr/interrupt.h>
+#include <avr/power.h>
+
+#include <stdio.h>
+#include <string.h>
+
+#include "util.h"
+#include "led.h"
+
+#include "heartbeat.h"
+#include "stepper.h"
+#include "ledmatrix.h"
+
+#include "LUFA/Drivers/Peripheral/TWI.h"
+#include "LUFA/Drivers/Peripheral/Serial.h"
+#include "LUFA/Drivers/Misc/RingBuffer.h"
+
+#include <avr/eeprom.h>
+#define EEPROM_SIZE 1024
+typedef uint8_t keyslot_t[8];
+keyslot_t EEMEM keystore[EEPROM_SIZE/sizeof(keyslot_t)];
+
+
+const char* SL018_cmd_tostring(const uint8_t cmd) 
+{
+  switch(cmd) {
+  case 0x01: return "Select Mifare card";
+  case 0x02: return "Login to a sector";
+  case 0x03: return "Read a data block";
+  case 0x04: return "Write a data block";
+  case 0x05: return "Read a value block";
+  case 0x06: return "Initialize a value block";
+  case 0x07: return "Write master key";
+  case 0x08: return "Increment value";
+  case 0x09: return "Decrement value";
+  case 0x0A: return "Copy value";
+  case 0x10: return "Read a data page";
+  case 0x11: return "Write a data page";
+  case 0x40: return "Control the red led";
+  case 0xF0: return "Get firmware version";
+  case 0xFF: return "Reset";
+  default: return "unknown";
+  }
+}
+
+const char* SL018_status_tostring(const uint8_t status) 
+{
+  switch(status) {
+  case 0x0: return "Operation succeed";
+  case 0x1: return "No tag";
+  case 0x2: return "Login succeed";
+  case 0x3: return "Login fail";
+  case 0x4: return "Read fail";
+  case 0x5: return "Write fail";
+  case 0x6: return "Unable to read after write";
+  case 0xA: return "Collision occur";
+  case 0xC: return "Load key fail";
+  case 0xD: return "Not authenticate";
+  case 0xE: return "Not a value block";
+  default: return "unknown";
+  }
+}
+
+const char* SL018_tagtype_tostring(const uint8_t type) 
+{
+  switch(type) {
+  case 0x1: return "Mifare 1k, 4 byte UID";
+  case 0x2: return "Mifare 1k, 7 byte UID";
+  case 0x3: return "Mifare Ultralight or NATG203, 7 byte UID";
+  case 0x4: return "Mifare 4k, 4 byte UID";
+  case 0x5: return "Mifare 4k, 7 byte UID";
+  case 0x6: return "Mifare DesFire, 7 byte UID";
+  default: return "unknown";
+  }
+}
+
+uint8_t SL018_tagtype_to_uidlen(const uint8_t type) 
+{
+  switch(type) {
+  case 0x1:
+  case 0x4: return 4;
+  case 0x2:
+  case 0x3:
+  case 0x5:
+  case 0x6: return 7;
+  default: return 0;
+  }
+}
+
+const uint8_t SL018_CMD_ComSelectCard[]         = {1,0x01};
+const uint8_t SL018_CMD_ComRedLedOn[]           = {2,0x40,1};
+const uint8_t SL018_CMD_ComRedLedOff[]          = {2,0x40,0};
+const uint8_t SL018_CMD_ComGetFirmwareVersion[] = {1,0xF0};
+const uint8_t SL018_CMD_ComReset[]              = {1,0xFF};
+
+uint8_t twi_recv_buf[256];
+typedef struct __attribute__((__packed__))
+{
+  uint8_t len;
+  uint8_t command;
+  uint8_t status;
+  uint8_t data[sizeof(twi_recv_buf)-3];
+} sl018_message_t;
+
+sl018_message_t* twi_recv_msg = (sl018_message_t *)&twi_recv_buf;
+
+#define SL018_TWI_ADDR  0xA0
+#define SL018_TAG_STA_PIN PIND
+#define SL018_TAG_STA_BIT 7
+#define CARD_PRESENT (!((SL018_TAG_STA_PIN >> SL018_TAG_STA_BIT) & 1))
+uint8_t card_status = 0;
+
+
+
+FILE usb_stream;
+FILE serial_stream;
+FILE * stdio = &serial_stream;
+
+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2012.
+
+  dean [at] fourwalledcubicle [dot] com
+           www.lufa-lib.org
+*/
+
+
+#include <LUFA/Drivers/USB/USB.h>
+#include "lufa-descriptor-usbserial.h"
+
+USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
+  {
+    .Config =
+      {
+        .ControlInterfaceNumber         = 0,
+
+        .DataINEndpointNumber           = CDC_TX_EPNUM,
+        .DataINEndpointSize             = CDC_TXRX_EPSIZE,
+        .DataINEndpointDoubleBank       = false,
+
+        .DataOUTEndpointNumber          = CDC_RX_EPNUM,
+        .DataOUTEndpointSize            = CDC_TXRX_EPSIZE,
+        .DataOUTEndpointDoubleBank      = false,
+
+        .NotificationEndpointNumber     = CDC_NOTIFICATION_EPNUM,
+        .NotificationEndpointSize       = CDC_NOTIFICATION_EPSIZE,
+        .NotificationEndpointDoubleBank = false,
+      },
+  };
+
+void EVENT_USB_Device_ConfigurationChanged(void)
+{
+  CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);
+}
+
+void EVENT_USB_Device_ControlRequest(void)
+{
+  CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
+}
+
+void EVENT_CDC_Device_ControLineStateChanged(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo)	
+{
+  if(CDCInterfaceInfo->State.ControlLineStates.HostToDevice & CDC_CONTROL_LINE_OUT_DTR)
+    stdio = &usb_stream;
+  else
+    stdio = &serial_stream;
+}
+
+void EVENT_USB_Device_Disconnect(void)
+{
+  stdio = &serial_stream;
+}
+/* end LUFA CDC-ACM specific definitions*/
+
+
+
+int16_t stdio_bytes_received(void)
+{
+  if(stdio == &usb_stream)
+    return CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface);
+  else
+    return (int16_t)Serial_IsCharReceived();
+}
+
+uint8_t sl018_cmd_raw(const uint8_t* twi_send_buf, bool wait_for_answer)
+{
+  uint8_t pos = 0;
+
+  if (TWI_StartTransmission(SL018_TWI_ADDR | TWI_ADDRESS_WRITE,10) == TWI_ERROR_NoError) {
+    for(pos=0; pos<=twi_send_buf[0]; pos++) {
+      if( ! TWI_SendByte(twi_send_buf[pos])) {
+        TWI_StopTransmission();
+        return 1;
+      }
+    }
+    TWI_StopTransmission();
+  } else 
+    return 1;
+
+  if(!wait_for_answer) return 0;
+
+  memset(twi_recv_buf, 0, sizeof(twi_recv_buf));
+  _delay_ms(50);
+
+  if (TWI_StartTransmission(SL018_TWI_ADDR | TWI_ADDRESS_READ,10) == TWI_ERROR_NoError) {
+    TWI_ReceiveByte(twi_recv_buf, 0);
+    for(pos=1; pos<=twi_recv_buf[0]; pos++) {
+      if (! TWI_ReceiveByte(&twi_recv_buf[pos], (pos == twi_recv_buf[0]) ? 1:0 ) ) {
+        TWI_StopTransmission();
+        return 1;
+      }
+    }
+    TWI_StopTransmission();
+  } else
+    return 1;
+
+  return 0;
+}
+
+uint8_t sl018_reset(void)
+{
+  if(sl018_cmd_raw(SL018_CMD_ComReset, 0)) {
+    fprintf(stdio, "I2C error\n\r");
+    return 1;
+  }
+  return 0;
+}
+
+uint8_t sl018_cmd(const uint8_t* twi_send_buf)
+{
+  if(sl018_cmd_raw(twi_send_buf, 1)) {
+    fprintf(stdio, "I2C error\n\r");
+    return 1;
+  } else {
+    if(twi_recv_msg->len < 2) {
+      fprintf(stdio,"SL018 Cmd,Error: short message received\n\r");
+      return 1;
+    }
+    if(twi_recv_msg->status) {
+      fprintf(stdio,"SL018 Cmd,Error: '%s','%s'\n\r",SL018_cmd_tostring(twi_recv_msg->command),SL018_status_tostring(twi_recv_msg->status));
+      return 1;
+    }
+    sl018_message_t * twi_send_msg = (sl018_message_t *)twi_send_buf;
+    if(twi_send_msg->command != twi_recv_msg->command) {
+      fprintf(stdio,"SL018 Cmd,Error: mismatch of sent and received command code: %02X,%02X\n\r",twi_send_msg->command,twi_recv_msg->command);
+    }
+  }
+  return 0;
+}
+
+
+
+void flash_keystore_from_stdio(void)
+{
+  keyslot_t ks;
+  uint8_t byte_pos=0;
+  fprintf(stdio,"Flashing keys:\n\r");
+  fflush(stdio);
+  for(uint8_t ks_pos=0;ks_pos<EEPROM_SIZE/sizeof(ks);) {
+    CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
+    USB_USBTask();
+
+    int16_t bytes_received = stdio_bytes_received();
+    while(bytes_received > 0) {
+      ks[byte_pos++]=fgetc(stdio);
+      bytes_received--;
+      if (byte_pos == sizeof(ks)) {
+        byte_pos=0;
+        eeprom_update_block(&ks,&keystore[ks_pos],sizeof(ks));
+        ks_pos++;
+        fputc('.', stdio);
+        fflush(stdio);
+        led_toggle();
+      }
+    }
+  }
+  fprintf(stdio,"\n");
+  fputc(0, stdio);
+  led_off();
+}
+
+void dump_keystore_to_stdio(void)
+{
+  keyslot_t ks;
+  for(uint8_t ks_pos=0;ks_pos<EEPROM_SIZE/sizeof(ks);ks_pos++) {
+    eeprom_read_block(&ks,&keystore[ks_pos],sizeof(ks));
+    for (uint8_t i=0; i< sizeof(ks); i++)
+      fprintf(stdio,"%02X",ks[i]);
+    fprintf(stdio,"\n\r");
+  }
+}
+
+void handle_stdio(uint8_t cmd)
+{  
+  switch(cmd) {
+    case 'r': 
+             reset2bootloader(); 
+             break;
+    case 'R': 
+             if(!sl018_reset())
+               fprintf(stdio, "ok\n\r");
+             break;
+    case 'f': //get cardreader firmware version
+             if(!sl018_cmd(SL018_CMD_ComGetFirmwareVersion)) {
+               twi_recv_msg->data[sizeof(twi_recv_msg->data) - 1] = 0;
+               fprintf(stdio, "%s\n\r",twi_recv_msg->data);
+             }
+             break;
+    case 'e': //flash eeprom
+             flash_keystore_from_stdio();
+             break;
+    case 'd': //dump eeprom - this breaks security!
+             dump_keystore_to_stdio();
+             break;
+    case 'o': 
+             if(start_stepper(dir_open))
+               fprintf(stdio, "ok\n\r");
+             else
+               fprintf(stdio, "error: already in progress\n\r");
+             break;
+    case 'c': 
+             if(start_stepper(dir_close))
+               fprintf(stdio, "ok\n\r");
+             else
+               fprintf(stdio, "error: already in progress\n\r");
+             break;
+    case '0': ledmatrix(off); break;
+    case '1': ledmatrix(red); break;
+    case '2': ledmatrix(red_moving); break;
+    case '3': ledmatrix(red_blink); break;
+    case '4': ledmatrix(green); break;
+    case '5': ledmatrix(green_moving); break;
+    case '6': ledmatrix(green_blink); break;
+    case '7': ledmatrix(rg_moving); break;
+    case '8': ledmatrix(rg_blink); break;
+    default: fprintf(stdio, "error, unknown command %02X '%c'\n\r",cmd, cmd); return;
+  }
+}
+
+
+
+/* this generates a Fletcher8 checksum  */
+/* code from: http://stackoverflow.com/questions/13491700/8-bit-fletcher-checksum-of-16-byte-data */
+uint8_t generate_csum(uint8_t* data)
+{
+  uint16_t sum1 = 0xf, sum2 = 0xf, len = sizeof(keyslot_t) - 1;
+  do { sum2 += ( sum1 += *data++ ); } while (--len);
+  return sum2<<4 | sum1;
+}
+
+uint8_t compare_keyslots(const keyslot_t a, const keyslot_t b)
+{
+  uint8_t tmp=0;
+      // constant time compare
+  for(uint8_t i=0; i<sizeof(keyslot_t); ++i)
+    tmp |= a[i] ^ b[i];
+  return tmp;
+}
+
+bool check_card(const uint8_t * uid, uint8_t uid_len)
+{
+  keyslot_t card, ks;
+  memset(card, 0, sizeof(card));
+  for (uint8_t pos=0; pos<uid_len; pos++)
+    card[pos]=uid[uid_len-pos-1];
+  card[sizeof(keyslot_t)-1]=generate_csum(card);
+  bool valid=0;
+  for(uint8_t ks_pos=0;ks_pos<(EEPROM_SIZE/sizeof(ks));ks_pos++) {
+    eeprom_read_block(&ks,&keystore[ks_pos],sizeof(ks));
+    if(!compare_keyslots(card, ks)) {
+      valid=1;
+      // break;  // this would break security (not constant time)
+    }
+  }
+  return valid;
+}
+
+void handle_card(void)
+{
+  fprintf(stdio, "CARD IN: ");
+  if(!sl018_cmd(SL018_CMD_ComSelectCard))
+  {
+    uint8_t uid_len = twi_recv_msg->len - sizeof(twi_recv_msg->command) - sizeof(twi_recv_msg->status) - 1;
+    if(uid_len == 255 || uid_len > sizeof(keyslot_t) - 1) {
+      fprintf(stdio," received UID length (%d) is to big for keystore \n\r", uid_len);
+      return;
+    }
+    uint8_t type = twi_recv_msg->data[uid_len];
+    uint8_t expected_uid_len = SL018_tagtype_to_uidlen(type);
+    if(expected_uid_len != uid_len) {
+      fprintf(stdio," Invalid uid length (%d) for tag type: %s\n\r", uid_len, SL018_tagtype_tostring(type));
+      return;
+    }    
+
+    for (uint8_t pos=0; pos<uid_len; pos++)
+      fprintf(stdio,"%02X",twi_recv_msg->data[uid_len-pos-1]);
+    fprintf(stdio, ", %s\n\r", SL018_tagtype_tostring(type));
+
+    if (0 < type && type < 7) {
+      if(check_card(twi_recv_msg->data,uid_len)) {
+        sl018_cmd(SL018_CMD_ComRedLedOn);
+        fprintf(stdio,"Card allowed - opening/closing door\n\r"); // TODO: open/close door!
+        _delay_ms(255);
+        sl018_cmd(SL018_CMD_ComRedLedOff);
+      } else {
+        fprintf(stdio,"Card not found in Database\n\r");
+      }
+    } else {
+      fprintf(stdio,"Ignoring unknown card type %02x\n\r",type);
+    }
+  }  
+}
+
+
+
+int main(void)
+{
+  MCUSR &= ~(1 << WDRF);
+  wdt_disable();
+
+  cpu_init();
+  led_init();
+  USB_Init();
+  TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 200000));
+  Serial_Init(115200,false);
+  Serial_CreateStream(&serial_stream);
+  CDC_Device_CreateStream(&VirtualSerial_CDC_Interface,&usb_stream);
+
+  sei();  
+
+  init_heartbeat();
+  init_stepper();
+  init_ledmatrix();
+
+  sl018_reset();
+
+  for(;;) {
+    CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
+    USB_USBTask();
+
+    int16_t bytes_received = stdio_bytes_received();
+    if(bytes_received > 0)
+      handle_stdio(fgetc(stdio));
+
+    if(CARD_PRESENT != card_status) {
+      card_status = CARD_PRESENT;
+      if(card_status)
+        handle_card();
+    }
+
+    handle_heartbeat();
+  }
+}