InetrfaceProducts NXP / PCF2127

PCF2127 and PCF2129 are high accuracy real-time-clock (RTC) module. This library provides simple interface to accessing clock information.

Dependents:   PCF2127_Demo PCF2127_Hello

PCF2127 and PCF2129

PCF2127T PCF2127T is in SO16 package

The PCF2127 and the PCF2129 are a CMOS Real Time Clock (RTC) and calendar with an integrated Temperature Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartz crystal optimized for very high accuracy and very low power consumption.
Both of PCF2127 and PCF2129 have a selectable I2C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function, a timestamp function, and many other features.
On addition to this, the PCF2127 has 512 bytes of general-purpose static RAM.

These 4 types of RTC modules are software compatible. So this library "PCF2127" can be used all of those.
This library only supports I2C to communicate with the PCF2127/PCF2129.

Type variations

Main feature difference

type+/-3ppm accuracy range512 bytes RAMpackage
PCF2127T-30℃ to +80℃yesSO16
PCF2127AT-30℃ to +60℃yesSO20
PCF2129T-30℃ to +80℃not availableSO16
PCF2129AT-15℃ to +60℃not availableSO20

Pin assign

/media/uploads/nxp_ip/pcf2127_pcf2129_pin_assign.png

PCF2127T
PCF2127T

Connection between MCU and PCF2127/PCF2129

These examples show how the RTC module can be connected via I2C bus.

http://developer.mbed.org/media/components/pinouts/both_types_connection3.png

References

PCF2127.h@1:700e0285cfd8, 2014-12-09 (annotated)

Committer:
nxp_ip
Date:
Tue Dec 09 07:21:13 2014 +0000
Revision:
1:700e0285cfd8
Parent:
0:1377bcf1455e
Child:
2:db76c68f998f
version 1.6:; changed: "battery switch-over function" as standard mode; changed: "CLKOUT" frequency is 1Hz; added: constructor by I2C object; added: set_time( time_t *tp ) function

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nxp_ip 0:1377bcf1455e 1 /*
nxp_ip 0:1377bcf1455e 2 * PCF2127 library
nxp_ip 0:1377bcf1455e 3 *
nxp_ip 0:1377bcf1455e 4 * @author Akifumi (Tedd) OKANO, NXP Semiconductors
nxp_ip 1:700e0285cfd8 5 * @version 1.6
nxp_ip 1:700e0285cfd8 6 * @date 09-Dec-2014
nxp_ip 0:1377bcf1455e 7 *
nxp_ip 0:1377bcf1455e 8 * PCF2127 is a "real time clock (RTC)" module which is including a Xtal and TCXO
nxp_ip 0:1377bcf1455e 9 * http://www.nxp.com/products/interface_and_connectivity/real_time_clocks/rtcs_with_temp_compensation/series/PCF2127.html
nxp_ip 0:1377bcf1455e 10 *
nxp_ip 0:1377bcf1455e 11 * RTC initializing part is ported from..
nxp_ip 0:1377bcf1455e 12 * http://mbed.org/users/roen/notebook/real-time/
nxp_ip 0:1377bcf1455e 13 *
nxp_ip 0:1377bcf1455e 14 * This code is refined version of..
nxp_ip 0:1377bcf1455e 15 * http://developer.mbed.org/users/okano/code/NXP_PCF2127A/
nxp_ip 0:1377bcf1455e 16 */
nxp_ip 0:1377bcf1455e 17
nxp_ip 0:1377bcf1455e 18 #ifndef MBED_PCF2127
nxp_ip 0:1377bcf1455e 19 #define MBED_PCF2127
nxp_ip 0:1377bcf1455e 20
nxp_ip 0:1377bcf1455e 21 #include "mbed.h"
nxp_ip 0:1377bcf1455e 22
nxp_ip 0:1377bcf1455e 23 class PCF2127
nxp_ip 0:1377bcf1455e 24 {
nxp_ip 0:1377bcf1455e 25 public:
nxp_ip 0:1377bcf1455e 26
nxp_ip 0:1377bcf1455e 27 /** name of the PCF2127 registers */
nxp_ip 0:1377bcf1455e 28 typedef enum {
nxp_ip 0:1377bcf1455e 29 Control_1,
nxp_ip 0:1377bcf1455e 30 Control_2,
nxp_ip 0:1377bcf1455e 31 Control_3,
nxp_ip 0:1377bcf1455e 32 Seconds,
nxp_ip 0:1377bcf1455e 33 Minutes,
nxp_ip 0:1377bcf1455e 34 Hours,
nxp_ip 0:1377bcf1455e 35 Days,
nxp_ip 0:1377bcf1455e 36 Weekdays,
nxp_ip 0:1377bcf1455e 37 Months,
nxp_ip 0:1377bcf1455e 38 Years,
nxp_ip 0:1377bcf1455e 39 Second_alarm,
nxp_ip 0:1377bcf1455e 40 Minute_alarm,
nxp_ip 0:1377bcf1455e 41 Hour_alarm,
nxp_ip 0:1377bcf1455e 42 Day_alarm,
nxp_ip 0:1377bcf1455e 43 Weekday_alarm,
nxp_ip 0:1377bcf1455e 44 CLKOUT_ctl,
nxp_ip 0:1377bcf1455e 45 Watchdg_tim_ctl,
nxp_ip 0:1377bcf1455e 46 Watchdg_tim_val,
nxp_ip 0:1377bcf1455e 47 Timestp_ctl,
nxp_ip 0:1377bcf1455e 48 Sec_timestp,
nxp_ip 0:1377bcf1455e 49 Min_timestp,
nxp_ip 0:1377bcf1455e 50 Hour_timestp,
nxp_ip 0:1377bcf1455e 51 Day_timestp,
nxp_ip 0:1377bcf1455e 52 Mon_timestp,
nxp_ip 0:1377bcf1455e 53 Year_timestp,
nxp_ip 0:1377bcf1455e 54 Aging_offset
nxp_ip 0:1377bcf1455e 55 }
nxp_ip 0:1377bcf1455e 56 RegisterName;
nxp_ip 1:700e0285cfd8 57
nxp_ip 1:700e0285cfd8 58 /** Error code */
nxp_ip 1:700e0285cfd8 59 typedef enum {
nxp_ip 1:700e0285cfd8 60 NO_ERROR = 0,
nxp_ip 1:700e0285cfd8 61 CLOCK_INTEGRITY_FAIL = 1,
nxp_ip 1:700e0285cfd8 62 I2C_ACCESS_FAIL = 2,
nxp_ip 1:700e0285cfd8 63 TIME_FUNC_ERROR = ((time_t)-1)
nxp_ip 1:700e0285cfd8 64 }
nxp_ip 1:700e0285cfd8 65 ErrorNum;
nxp_ip 1:700e0285cfd8 66
nxp_ip 0:1377bcf1455e 67 /** Create a PCF2127 instance connected to specified I2C pins with specified address
nxp_ip 0:1377bcf1455e 68 *
nxp_ip 0:1377bcf1455e 69 * @param I2C_sda I2C-bus SDA pin
nxp_ip 0:1377bcf1455e 70 * @param I2C_scl I2C-bus SCL pin
nxp_ip 1:700e0285cfd8 71 * @param vControl_1 (option) data for Control_1 register (default setting generates interrupts by second and minute)
nxp_ip 0:1377bcf1455e 72 * @param vControl_2 (option) data for Control_2 register
nxp_ip 1:700e0285cfd8 73 * @param vControl_3 (option) data for Control_3 register (default setting of battery switch-over function as standard mode)
nxp_ip 1:700e0285cfd8 74 * @param vCLKOUT_ctl (option) data for CLKOUT_ctl register (default setting 1Hz output on CLKOUT pin)
nxp_ip 1:700e0285cfd8 75 CLKOUT_ctl
nxp_ip 0:1377bcf1455e 76 */
nxp_ip 1:700e0285cfd8 77 PCF2127( PinName sda, PinName sdl, char vControl_1 = Cntl1, char vControl_2 = Cntl2, char vControl_3 = Cntl1, char vCLKOUT_ctl = ClkOut );
nxp_ip 0:1377bcf1455e 78
nxp_ip 1:700e0285cfd8 79 /** Create a PCF2127 instance connected to specified I2C pins with specified address
nxp_ip 1:700e0285cfd8 80 *
nxp_ip 1:700e0285cfd8 81 * @param i2c I2C object (instance)
nxp_ip 1:700e0285cfd8 82 * @param vControl_1 (option) data for Control_1 register (default setting generates interrupts by second and minute)
nxp_ip 1:700e0285cfd8 83 * @param vControl_2 (option) data for Control_2 register
nxp_ip 1:700e0285cfd8 84 * @param vControl_3 (option) data for Control_3 register (default setting of battery switch-over function as standard mode)
nxp_ip 1:700e0285cfd8 85 * @param vCLKOUT_ctl (option) data for CLKOUT_ctl register (default setting 1Hz output on CLKOUT pin)
nxp_ip 1:700e0285cfd8 86 */
nxp_ip 1:700e0285cfd8 87 PCF2127( I2C &i2c, char vControl_1 = Cntl1, char vControl_2 = Cntl2, char vControl_3 = Cntl1, char vCLKOUT_ctl = ClkOut );
nxp_ip 1:700e0285cfd8 88
nxp_ip 0:1377bcf1455e 89 /** Destractor
nxp_ip 0:1377bcf1455e 90 */
nxp_ip 0:1377bcf1455e 91 ~PCF2127();
nxp_ip 0:1377bcf1455e 92
nxp_ip 0:1377bcf1455e 93 /** Clock integrity check
nxp_ip 0:1377bcf1455e 94 *
nxp_ip 0:1377bcf1455e 95 * @return non-zero value if the clock was stopped (means need to set the time)
nxp_ip 0:1377bcf1455e 96 */
nxp_ip 0:1377bcf1455e 97 int is_init_required( void );
nxp_ip 0:1377bcf1455e 98
nxp_ip 0:1377bcf1455e 99 /** Set the time
nxp_ip 0:1377bcf1455e 100 *
nxp_ip 0:1377bcf1455e 101 * @param dtp Pointer to struct tm
nxp_ip 0:1377bcf1455e 102 */
nxp_ip 1:700e0285cfd8 103 int set_time( struct tm *dtp );
nxp_ip 1:700e0285cfd8 104
nxp_ip 1:700e0285cfd8 105 /** Set the time
nxp_ip 1:700e0285cfd8 106 *
nxp_ip 1:700e0285cfd8 107 * @param tp pointer to time_t
nxp_ip 1:700e0285cfd8 108 */
nxp_ip 1:700e0285cfd8 109 int set_time( time_t *tp );
nxp_ip 0:1377bcf1455e 110
nxp_ip 0:1377bcf1455e 111 /** Set the time
nxp_ip 0:1377bcf1455e 112 * @param s String data: The time information should be given in format of "YYYY MM DD HH MM SS"
nxp_ip 0:1377bcf1455e 113 */
nxp_ip 1:700e0285cfd8 114 int set_time( char *s );
nxp_ip 0:1377bcf1455e 115
nxp_ip 0:1377bcf1455e 116 /** Get time of day
nxp_ip 0:1377bcf1455e 117 *
nxp_ip 0:1377bcf1455e 118 * This function works similar to "time()" in standard-C-library
nxp_ip 0:1377bcf1455e 119 *
nxp_ip 0:1377bcf1455e 120 * @param tp Pointer to time_t
nxp_ip 0:1377bcf1455e 121 */
nxp_ip 0:1377bcf1455e 122 time_t time( time_t *tp );
nxp_ip 0:1377bcf1455e 123
nxp_ip 0:1377bcf1455e 124 /** Register access interface with integer to BCD conversion
nxp_ip 0:1377bcf1455e 125 *
nxp_ip 0:1377bcf1455e 126 * @param addr Register address
nxp_ip 0:1377bcf1455e 127 * @param Integer data. Converted to BCD before writing inot the register.
nxp_ip 0:1377bcf1455e 128 */
nxp_ip 1:700e0285cfd8 129 int set_alarm( char addr, char s );
nxp_ip 0:1377bcf1455e 130
nxp_ip 0:1377bcf1455e 131 /** Clear interrupt flag
nxp_ip 0:1377bcf1455e 132 *
nxp_ip 0:1377bcf1455e 133 * Clears interrupt flags by writing 0x00 into Control_2 register
nxp_ip 0:1377bcf1455e 134 *
nxp_ip 0:1377bcf1455e 135 */
nxp_ip 1:700e0285cfd8 136 int clear_intr( void );
nxp_ip 0:1377bcf1455e 137
nxp_ip 0:1377bcf1455e 138 private:
nxp_ip 0:1377bcf1455e 139
nxp_ip 1:700e0285cfd8 140 typedef enum {
nxp_ip 1:700e0285cfd8 141 Cntl1 = 0x03,
nxp_ip 1:700e0285cfd8 142 Cntl2 = 0x00,
nxp_ip 1:700e0285cfd8 143 Cntl3 = 0x00,
nxp_ip 1:700e0285cfd8 144 ClkOut = 0x46
nxp_ip 1:700e0285cfd8 145 }
nxp_ip 1:700e0285cfd8 146 DefaultRegParam;
nxp_ip 1:700e0285cfd8 147
nxp_ip 1:700e0285cfd8 148 int init( char vControl_1, char vControl_2, char vControl_3, char vCLKOUT_ctl );
nxp_ip 1:700e0285cfd8 149 int set_register( char addr, char data );
nxp_ip 1:700e0285cfd8 150 int read_register( char addr );
nxp_ip 1:700e0285cfd8 151 char i2bcd( char n );
nxp_ip 1:700e0285cfd8 152 char bcd2i( char bcd );
nxp_ip 1:700e0285cfd8 153
nxp_ip 1:700e0285cfd8 154 I2C *i2c_p;
nxp_ip 1:700e0285cfd8 155 I2C &i2c;
nxp_ip 0:1377bcf1455e 156 char device_address;
nxp_ip 0:1377bcf1455e 157 }
nxp_ip 0:1377bcf1455e 158 ;
nxp_ip 0:1377bcf1455e 159 #endif // end of "#ifndef MBED_PCF2127"