24LCxx_I2C.h

00001 /* mbed simplified access to Microchip 24LCxx Serial EEPROM devices (I2C)
00002  * Copyright (c) 2010-2012 ygarcia, MIT License
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
00005  * and associated documentation files (the "Software"), to deal in the Software without restriction, 
00006  * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
00007  * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
00008  * furnished to do so, subject to the following conditions:
00009  *
00010  * The above copyright notice and this permission notice shall be included in all copies or 
00011  * substantial portions of the Software.
00012  *
00013  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
00014  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
00015  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
00016  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
00017  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00018  */
00019 #if !defined(__24LCXX_I2C_H__)
00020 #define __24LCXX_I2C_H__
00021 
00022 #include <string>
00023 #include <vector>
00024 
00025 #include "Debug.h" // Include mbed header + debug primitives. See DebugLibrary
00026 
00027 namespace _24LCXX_I2C {
00028     /** This class provides simplified I2C access to a Microchip 24LCxx Serial EEPROM device. V0.0.0.3
00029      *
00030      * Note that if the LPC1768 is powered in 3.3V and Microchip 24LCxx Serial EEPROM device could be powered at 3.3V or 5V.
00031      * In this case, you shall use a bi-directional level shifter for I2C-bus. Please refer to AN97055 (http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf)
00032      * Microchip 24LCxx Serial EEPROM device reference:
00033      * - 24LC256: DS21203K
00034      * - 24LC64 : DS21189D
00035      *
00036      * Note that for I2C details, please visit http://www.datelec.fr/fiches/I2C.htm
00037      *
00038      * Note that this header file include following headers:
00039      * - <string>
00040      * - <vector>
00041      * - <mbed.h>
00042      *
00043      * @remark This class was validated with Tektronix TDS2014 oscilloscope in 3.3V and in mixte power mode 3.3V for mbed and 5V for the Microchip 24LCxx Serial EEPROM device
00044      * @author Yann Garcia (Don't hesitate to contact me: garcia.yann@gmail.com)
00045      */
00046     class C24LCXX_I2C { // TODO: Add EE Polling for write methods
00047         /** Reference counter used to guarentee unicity of the instance of I2C class
00048          */
00049         static unsigned char I2CModuleRefCounter;
00050         
00051         /** Device address input: A0, A1, A2 (Pins <1,3>). See DS21203K/DS21189D - Figure 5-1: Control Byte Format for address format details
00052          */
00053         unsigned char _slaveAddress;
00054         /** WP state indicator (pin 7); true is write protected, false otherwise
00055          */
00056         DigitalOut *_wp;
00057         /** An unique instance of I2C class
00058          */
00059         I2C *_i2cInstance;
00060     public:
00061         /** Memory storage mode
00062          */
00063         enum Mode {
00064             LittleEndian, //<! Little Endian mode: 0xA0B70708 is stored as 08: MSB and A0 LSB
00065             BigEndian //<! Little Endian mode: 0xA0B70708 is stored as AO: MSB and 08 LSB
00066         };
00067     public:
00068         /** Constructor with Write Protect command pin wired. Use it to manage the first I2C module on 3.3V or 5V network
00069          *
00070          * @param p_sda: MBed pin for SDA
00071          * @param p_scl: MBed pin for SCL
00072          * @param p_address: Device address input: A0, A1, A2 (Pins <1,3>)
00073          * @param p_wp: MBed pin to manage Write Protect input. If NC, WP is not managed, default value is NC, not connected
00074          * @param p_frequency: Frequency of the I2C interface (SCL), default value is 400KHz
00075          * Example:
00076          * - If A1 and A2 pins are tired to Vdd and A0 is tired to Vss, address shall '00000110'B
00077          * - If A0 and A1 pins are tired to Vss and A2 is tired to Vdd, address shall '00000100'B
00078          */
00079         C24LCXX_I2C(const PinName p_sda, const PinName p_scl, const unsigned char p_address, const PinName p_wp = NC, const unsigned int p_frequency = 400000);
00080     
00081         /** Destructor
00082          */
00083         virtual ~C24LCXX_I2C();
00084 
00085         /** Used to return the unique instance of I2C instance
00086          */
00087         inline const I2C * operator * () { return (const I2C *)_i2cInstance; };
00088 
00089         /** Erase of memory area starting at the specified address, using the specified pattern to fill the memory area
00090          *
00091          * @param p_startAddress The address of the memory area (from 0 to N - 1, N is the number of cells of the memory)
00092          * @param p_count The size of the memory area to erase
00093          * @param p_pattern The pattern value to use to fill the memory area. Default vqlue: 0x00
00094          * @return true on success, false otherwise
00095          * Exemple:
00096          * @code
00097          * ...
00098          * myEEPROM.EraseMemoryArea(0, 1024); // Set to 0x00 the first 1Kb memory 
00099          * ...
00100          * @endcode
00101          */
00102         bool EraseMemoryArea(const short p_startAddress, const int p_count, const unsigned char p_pattern = 0x00);
00103     
00104         /** Write a byte at the specified memory address
00105          *
00106          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00107          * @param p_byte The byte value to save
00108          * @return true on success, false otherwise
00109          * Exemple:
00110          * @code
00111          * unsigned char value = 0xaa;
00112          * ...
00113          * myEEPROM.Write(memoryAddress, value);
00114          * ...
00115          * @endcode
00116          */
00117         bool Write(const short p_address, const unsigned char p_byte);
00118     
00119         /** Write a short at the specified memory address according to the specified mode
00120          *
00121          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00122          * @param p_short The short value to save
00123          * @param p_mode The storage mode. Default value: BigEndian
00124          * @return true on success, false otherwise
00125          * Exemple:
00126          * @code
00127          * short value = 0xcafe;
00128          * ...
00129          * myEEPROM.Write(memoryAddress, value, LittleEndian);
00130          * ...
00131          * @endcode
00132          */
00133         bool Write(const short p_address, const short p_short, const C24LCXX_I2C::Mode p_mode = BigEndian);
00134     
00135         /** Write an integer at the specified memory address according to the specified mode
00136          *
00137          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00138          * @param p_int The integer value to save
00139          * @param p_mode The storage mode. Default value: BigEndian
00140          * @return true on success, false otherwise
00141          * Exemple:
00142          * @code
00143          * int value = 0xcafedeca;
00144          * ...
00145          * myEEPROM.Write(memoryAddress, value, LittleEndian);
00146          * ...
00147          * @endcode
00148          */
00149         bool Write(const short p_address, const int p_int, const C24LCXX_I2C::Mode p_mode = BigEndian);
00150     
00151         /** Write a buffer of bytes at the specified memory address
00152          *
00153          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00154          * @param p_datas The string to save
00155          * @param p_storeLength If true, store also the length of the buffer in Big Endian mode, otherwise the length will be provided by p_length2write parameter. Default value: true.
00156          * @param p_length2write The number of bytes to write, -1 for all characters. Default value: -1
00157          * @return true on success, false otherwise
00158          */
00159         bool Write(const short p_address, const std::vector<unsigned char> & p_datas, bool p_storeLength = true, const int p_length2write = -1);
00160     
00161         /** Write a buffer of bytes at the specified memory address
00162          *
00163          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00164          * @param p_datas The buffer of bytes to save
00165          * @param p_storeLength If true, store also the length of the buffer in Big Endian mode, otherwise the length will be provided by p_length2write parameter. Default value: true.
00166          * @param p_length2write The number of bytes to write, -1 for all bytes. Default value: -1
00167          * @return true on success, false otherwise
00168          */
00169         bool Write(const short p_address, const unsigned char *p_datas, bool p_storeLength = true, const int p_length2write = -1);
00170     
00171         /** Write a string at the specified memory address
00172          *
00173          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00174          * @param p_string The string to save
00175          * @param p_storeLength If true, store also the length of the string in Big Endian mode, otherwise the length will be provided by p_length2write parameter. Default value: true.
00176          * @param p_length2write The number of character to write, -1 for all characters
00177          * @return true on success, false otherwise
00178          * Exemple:
00179          * @code
00180          * std::string text2save("CafeDeca");
00181          * ...
00182          * myEEPROM.Write(memoryAddress, text2save);
00183          * ...
00184          * @endcode
00185          */
00186         bool Write(const short p_address, const std::string & p_string, const bool p_storeLength = true, const int p_length2write = -1);
00187     
00188         /** Write a buffer of characters at the specified memory address (from 0 to N - 1, N is the number of cells of the memory)
00189          *
00190          * Note that the length of the buffer is not saved and the string is saved in Big Endian mode
00191          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00192          * @param p_datas The string to save
00193          * @param p_storeLength If true, store also the length of the string in Big Endian mode, otherwise the length will be provided by p_length2write parameter. Default value: true.
00194          * @param length2write The number of character to write, -1 for all characters
00195          * @return true on success, false otherwise
00196          */
00197         bool Write(const short p_address, const char *p_datas, const bool p_storeLength = true, const int p_length2write = -1);
00198     
00199         /** Read a byte from the specified memory address
00200          *
00201          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00202          * @param p_byte The byte value to read
00203          * @return true on success, false otherwise
00204          * Exemple:
00205          * @code
00206          * unsigned char value;
00207          * ...
00208          * myEEPROM.Read(memoryAddress, (unsigned char *)&value);
00209          * ...
00210          * @endcode
00211          */
00212         bool Read(const short p_address, unsigned char *p_value);
00213     
00214         /** Read a short from the specified memory address
00215          *
00216          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00217          * @param p_short The short value to read
00218          * @return true on success, false otherwise
00219          * Exemple:
00220          * @code
00221          * short value;
00222          * ...
00223          * myEEPROM.Read(memoryAddress, (short *)&value);
00224          * ...
00225          * @endcode
00226          */
00227         bool Read(const short p_address, short *p_short, C24LCXX_I2C::Mode p_mode = BigEndian);
00228     
00229         /** Read an integer from the specified memory address
00230          *
00231          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00232          * @param p_int The integer value to read
00233          * @return true on success, false otherwise
00234          * Exemple:
00235          * @code
00236          * int value;
00237          * ...
00238          * myEEPROM.Read(memoryAddress, (int *)&value);
00239          * ...
00240          * @endcode
00241          */
00242         bool Read(const short p_address, int *p_int, C24LCXX_I2C::Mode p_mode = BigEndian);
00243     
00244         /** Read a buffer of bytes from the specified memory address and store it into a std::vector<unsigned char> object
00245          *
00246          * Note that the size of the buffer object is used for the number of bytes to read
00247          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00248          * @param p_datas The buffer to fill
00249          * @param p_readLengthFirst If true, read the length first and p_length2write parameter is ignored, otherwise the length is provided by p_length2write parameter. Default value: true
00250          * @param p_length2read The number of character to write, -1 to use the size of the string buffer
00251          * @return true on success, false otherwise
00252          * Exemple:
00253          * @code
00254          * std::vector<unsigned char> datas(bufferLength);
00255          * ...
00256          * myEEPROM.Read(memoryAddress, datas);
00257          * ...
00258          * @endcode
00259          */
00260         bool Read(const short p_address, std::vector<unsigned char> & p_datas, bool p_readLengthFirst = true, int p_length2read = -1);
00261     
00262         /** Read a buffer of characters from the specified memory address and store it into a string object
00263          *
00264          * Note that the size of the string object is used for the number of characters to read
00265          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00266          * @param p_string The string buffer to fill
00267          * @param p_readLengthFirst If true, read the length first and p_length2write parameter is ignored, otherwise the length is provided by p_length2write parameter. Default value: true
00268          * @param p_length2write The number of character to write, -1 to use the size of the string buffer
00269          * @return true on success, false otherwise
00270          * Exemple:
00271          * @code
00272          * std::string readtext;
00273          * ...
00274          * myEEPROM.Read(memoryAddress, readtext);
00275          * ...
00276          * @endcode
00277          */
00278         bool Read(const short p_address, std::string & p_string, bool p_readLengthFirst = true, int p_length2write = -1);
00279     
00280         /** Activate or deactivate write protect (pin 7)
00281          *
00282          * Note that a voltage of 3.3V apply to WP input of 24LCxx device is enough to enable write protect
00283          * @param p_writeProtect: Set to true to activate write protection, false otherwise
00284          * @return true on success, false otherwise
00285          */
00286         bool WriteProtect(const bool p_writeProtect);
00287     
00288         /** Indicate the current WP state indicator  (pin 7)
00289          * @return true is write protected, false otherwise
00290          */
00291         inline bool IsWriteProtected() {
00292             return (_wp != NULL) ? (bool)(_wp->read() == 1) : false;
00293         }
00294 
00295 #if defined(__DEBUG)
00296         /** Dump a memory area
00297          * 
00298          * Note that this method is available only on debug mode
00299          * @param p_address The memory address (from 0 to N - 1, N is the number of cells of the memory)
00300          * @param p_count The number of bytes toi dump
00301          * @return true on success, false otherwise
00302          */
00303         void DumpMemoryArea(const int p_address, const int p_count);
00304         /** For debug purpose only
00305          */
00306         inline std::string & ToString() { return _internalId; };
00307 #else // __DEBUG
00308         inline void DumpMemoryArea(const int p_address, const int p_count) {};
00309 #endif // _DEBUG
00310         
00311     private:
00312         /** Internal reference identifier
00313          */
00314         std::string _internalId;
00315 
00316     }; // End of class C24LCXX_I2C
00317 
00318 } // End of namespace _24LCXX_I2C
00319 
00320 using namespace _24LCXX_I2C;
00321 
00322 #endif // __24LCXX_I2C_H__