DS1302.h

00001 //The license: Its on the internet, have fun with it.
00002 
00003 #ifndef DS1302_H
00004 #define DS1302_H
00005 
00006 #include "mbed.h"
00007 
00008 /**
00009 * Library to make use of the DS1302 timekeeping IC
00010 *
00011 * The library functions the same as the standard mbed time function,
00012 * only now you have to first make a DS1302 object and apply the
00013 * functions on the object.
00014 *
00015 * Example code:
00016 * @code
00017 * #define SCLK    PTC5
00018 * #define IO      PTC4
00019 * #define CE      PTC3
00020 * 
00021 * //Comment this line if the DS1302 is already running
00022 * #define INITIAL_RUN
00023 * 
00024 * #include "mbed.h"
00025 * #include "DS1302.h"
00026 * 
00027 * DS1302 clk(SCLK, IO, PTC3);
00028 * 
00029 * int main() {
00030 *     #ifdef INITIAL_RUN
00031 *     clk.set_time(1256729737);
00032 *     #endif
00033 *     
00034 *     char storedByte = clk.recallByte(0);
00035 *     printf("Stored byte was %d, now increasing by one\r\n", storedByte);
00036 *     clk.storeByte(0, storedByte + 1);
00037 *     
00038 *     while(1) {
00039 *         time_t seconds = clk.time(NULL);
00040 *         printf("Time as a basic string = %s\r", ctime(&seconds));
00041 *         wait(1);
00042 *     }
00043 * }
00044 * @endcode
00045 *
00046 * See for example http://mbed.org/handbook/Time for general usage
00047 * of C time functions. 
00048 *
00049 * Trickle charging is not supported
00050 **/
00051 class DS1302
00052 {
00053 public:
00054     /** 
00055     * Register map
00056     */
00057     enum {
00058         Seconds = 0x80,
00059         Minutes = 0x82,
00060         Hours = 0x84,
00061         Dates = 0x86,
00062         Months = 0x88,
00063         Days = 0x8A,
00064         Years = 0x8C,
00065         WriteProtect = 0x8E,
00066         Charge = 0x90,
00067         ClockBurst = 0xBE,
00068         RAMBase = 0xC0
00069     };
00070 
00071     /**
00072     * Create a new DS1302 object
00073     *
00074     * @param SCLK the pin to which SCLK is connectd
00075     * @param IO the pin to which IO is connectd
00076     * @param CE the pin to which CE is connected (also called RST)
00077     */
00078     DS1302(PinName SCLK, PinName IO, PinName CE);
00079 
00080     /** Set the current time
00081     *
00082     * Initialises and sets the time of the DS1302
00083     * to the time represented by the number of seconds since January 1, 1970
00084     * (the UNIX timestamp).
00085     *
00086     * @param t Number of seconds since January 1, 1970 (the UNIX timestamp)
00087     *
00088     */
00089     void set_time(time_t  t);
00090 
00091     /** Get the current time
00092     *
00093     * Use other functions to convert this value, see: http://mbed.org/handbook/Time
00094     *
00095     * @param t ignored, supply NULL
00096     * @return number of seconds since January 1, 1970
00097     */
00098     time_t time(time_t  *t = NULL);
00099 
00100     /**
00101     * Store a byte in the battery-backed RAM
00102     *
00103     * @param address address where to store the data (0-30)
00104     * @param data the byte to store
00105     */
00106     void storeByte(char address, char data);
00107 
00108     /**
00109     * Recall a byte from the battery-backed RAM
00110     *
00111     * @param address address where to retrieve the data (0-30)
00112     * @return the stored data
00113     */
00114     char recallByte(char address);
00115 
00116     /**
00117     * Read a register
00118     *
00119     * Only required to for example manually set trickle charge register
00120     *
00121     * @param reg register to read
00122     * @return contents of the register
00123     */
00124     char readReg(char reg);
00125 
00126     /**
00127     * Write a register
00128     *
00129     * Only required to for example manually set trickle charge register
00130     *
00131     * @param reg register to write
00132     * @param val contents of the register to write
00133     */
00134     void writeReg(char reg, char val);
00135 
00136 protected:
00137 
00138     void writeByte(char data);
00139     char readByte(void);
00140 
00141     DigitalOut _SCLK;
00142     DigitalInOut _IO;
00143     DigitalOut _CE;
00144     bool writeProtect;
00145 
00146 
00147 };
00148 
00149 
00150 
00151 #endif