to colorize a colorful pixel with a simple touch using nfc technology

Dependencies:   Chainable_RGB_LED mbed

use Arch, NFC Shield and Grove - Chainable RGB LED to DIY a touch pixel. Then use an Android with NFC support to colorize it.

The project is on https://github.com/Seeed-Studio/TouchPixel

nfc/emulatetag.h

Committer:
yihui
Date:
2013-12-27
Revision:
0:88960f3eeb2c

File content as of revision 0:88960f3eeb2c:

/**************************************************************************/
/*!
    @file     emulatetag.h
    @author   Armin Wieser
    @license  BSD

    Implemented using NFC forum documents & library of libnfc
*/
/**************************************************************************/

#ifndef __EMULATETAG_H__
#define __EMULATETAG_H__

#include "PN532.h"

#define NDEF_MAX_LENGTH 128  // altough ndef can handle up to 0xfffe in size, arduino cannot.
typedef enum {COMMAND_COMPLETE, TAG_NOT_FOUND, FUNCTION_NOT_SUPPORTED, MEMORY_FAILURE, END_OF_FILE_BEFORE_REACHED_LE_BYTES} responseCommand;

class EmulateTag{

public:
EmulateTag(PN532Interface &interface) : pn532(interface), uidPtr(0), tagWrittenByInitiator(false), tagWriteable(true), updateNdefCallback(0) { }
  
  bool init();

  bool emulate(const uint16_t tgInitAsTargetTimeout = 0);

  /*
   * @param uid pointer to byte array of length 3 (uid is 4 bytes - first byte is fixed) or zero for uid 
   */
  void setUid(uint8_t* uid = 0);

  void setNdefFile(const uint8_t* ndef, const int16_t ndefLength);

  void getContent(uint8_t** buf, uint16_t* length){
    *buf = ndef_file + 2; // first 2 bytes = length
    *length = (ndef_file[0] << 8) + ndef_file[1];
  }

  bool writeOccured(){
    return tagWrittenByInitiator;
  }

  void setTagWriteable(bool setWriteable){
    tagWriteable = setWriteable;
  }

  uint8_t* getNdefFilePtr(){
    return ndef_file;
  }

  uint8_t getNdefMaxLength(){
    return NDEF_MAX_LENGTH;
  }

  void attach(void (*func)(uint8_t *buf, uint16_t length)) {
    updateNdefCallback = func;
  };

private:
  PN532 pn532;
  uint8_t ndef_file[NDEF_MAX_LENGTH];
  uint8_t* uidPtr;
  bool tagWrittenByInitiator;
  bool tagWriteable;
  void (*updateNdefCallback)(uint8_t *ndef, uint16_t length);

  void setResponse(responseCommand cmd, uint8_t* buf, uint8_t* sendlen, uint8_t sendlenOffset = 0);
};

#endif