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 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 range | 512 bytes RAM | package |
---|---|---|---|
PCF2127T | -30℃ to +80℃ | yes | SO16 |
PCF2127AT | -30℃ to +60℃ | yes | SO20 |
PCF2129T | -30℃ to +80℃ | not available | SO16 |
PCF2129AT | -15℃ to +60℃ | not available | SO20 |
Pin assign
PCF2127T
Connection between MCU and PCF2127/PCF2129
These examples show how the RTC module can be connected via I2C bus.
References
- Datasheet
- User manual
- Other information PCF2127
Revision 1:700e0285cfd8, committed 2014-12-09
- Comitter:
- nxp_ip
- Date:
- Tue Dec 09 07:21:13 2014 +0000
- Parent:
- 0:1377bcf1455e
- Child:
- 2:db76c68f998f
- Commit message:
- 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
Changed in this revision
PCF2127.cpp | Show annotated file Show diff for this revision Revisions of this file |
PCF2127.h | Show annotated file Show diff for this revision Revisions of this file |
--- a/PCF2127.cpp Thu Dec 04 04:58:24 2014 +0000 +++ b/PCF2127.cpp Tue Dec 09 07:21:13 2014 +0000 @@ -2,8 +2,8 @@ * PCF2127 library * * @author Akifumi (Tedd) OKANO, NXP Semiconductors - * @version 1.5 - * @date 04-Dec-2014 + * @version 1.6 + * @date 09-Dec-2014 * * PCF2127 is a "real time clock (RTC)" module which is including a Xtal and TCXO * http://www.nxp.com/products/interface_and_connectivity/real_time_clocks/rtcs_with_temp_compensation/series/PCF2127.html @@ -20,16 +20,38 @@ #define PCF2127_I2C_SLAVE_ADDRESS 0xA2 -PCF2127::PCF2127( PinName sda, PinName sdl, char vControl_1, char vControl_2, char vControl_3 ) - : i2c( sda, sdl ), device_address( PCF2127_I2C_SLAVE_ADDRESS ) +PCF2127::PCF2127( PinName sda, PinName sdl, char vControl_1, char vControl_2, char vControl_3, char vCLKOUT_ctl ) + : i2c_p( new I2C( sda, sdl ) ), i2c( *i2c_p ), device_address( PCF2127_I2C_SLAVE_ADDRESS ) { - set_register( Control_1, vControl_1 ); - set_register( Control_2, vControl_2 ); - set_register( Control_3, vControl_3 ); + init( vControl_1, vControl_2, vControl_3, vCLKOUT_ctl ); +} + +PCF2127::PCF2127( I2C &i2c_, char vControl_1, char vControl_2, char vControl_3, char vCLKOUT_ctl ) + : i2c_p( NULL ), i2c( i2c_ ), device_address( PCF2127_I2C_SLAVE_ADDRESS ) +{ + init( vControl_1, vControl_2, vControl_3, vCLKOUT_ctl ); } PCF2127::~PCF2127() { + if ( NULL != i2c_p ) + delete i2c_p; +} + +int PCF2127::init( char vControl_1, char vControl_2, char vControl_3, char vCLKOUT_ctl ) +{ + char data[ 4 ]; + int err; + + data[ 0 ] = Control_1; // access start register address + data[ 1 ] = vControl_1; + data[ 2 ] = vControl_2; + data[ 3 ] = vControl_3; + + err = i2c.write( device_address, data, sizeof( data ) ); + err |= set_register( CLKOUT_ctl, vCLKOUT_ctl ); + + return ( err ? I2C_ACCESS_FAIL : NO_ERROR ); } int PCF2127::is_init_required( void ) @@ -37,10 +59,10 @@ return ( read_register( Seconds ) & 0x80 ? true : false ); } -void PCF2127::set_time( struct tm *dtp ) +int PCF2127::set_time( struct tm *dtp ) { char buf[ 8 ]; - char c; + char err; buf[ 0 ] = Seconds; buf[ 1 ] = i2bcd( dtp->tm_sec ); @@ -51,14 +73,17 @@ buf[ 6 ] = i2bcd( dtp->tm_mon + 1 ); buf[ 7 ] = i2bcd( dtp->tm_year - 100 ); - c = read_register( Seconds ); - while ( c == read_register( Seconds ) ) - ; - - i2c.write( device_address, buf, 8 ); + err = i2c.write( device_address, buf, 8 ); + + return ( err ? I2C_ACCESS_FAIL : NO_ERROR ); } -void PCF2127::set_time( char *s ) +int PCF2127::set_time( time_t *tp ) +{ + return ( set_time( localtime( tp ) ) ); +} + +int PCF2127::set_time( char *s ) { // The time information should be given in format of "YYYY MM DD HH MM SS" @@ -67,25 +92,30 @@ dtp = &dt; sscanf( s, "%d %d %d %d %d %d", &(dtp->tm_year), &(dtp->tm_mon), &(dtp->tm_mday), &(dtp->tm_hour), &(dtp->tm_min), &(dtp->tm_sec) ); - printf( "%d/%d/%d - %d:%d:%d\r\n", (dtp->tm_year), (dtp->tm_mon), (dtp->tm_mday), (dtp->tm_hour), (dtp->tm_min), (dtp->tm_sec) ); + printf( "%02d/%02d/%02d - %02d:%02d:%02d\r\n", (dtp->tm_year), (dtp->tm_mon), (dtp->tm_mday), (dtp->tm_hour), (dtp->tm_min), (dtp->tm_sec) ); // adjust for tm structure required values dtp->tm_year = dtp->tm_year - 1900; dtp->tm_mon = dtp->tm_mon - 1; - set_time( dtp ); + return ( set_time( dtp ) ); } time_t PCF2127::time( time_t *tp ) { struct tm dt, *dtp; time_t t; - char buf[ 8 ] = { Seconds }; + char buf[ 8 ]; dtp = &dt; - i2c.write( device_address, buf, 1 ); - i2c.read( device_address, buf, 7 ); + buf[ 0 ] = Seconds; // read start register address + + if ( i2c.write( device_address, buf, 1 ) ) + return ( TIME_FUNC_ERROR ); + + if ( i2c.read( device_address, buf, 7 ) ) + return ( TIME_FUNC_ERROR ); dtp->tm_sec = bcd2i( buf[ 0 ] ); dtp->tm_min = bcd2i( buf[ 1 ] ); @@ -103,30 +133,31 @@ return( t ); } -void PCF2127::set_alarm( char addr, char s ) +int PCF2127::set_alarm( char addr, char s ) { char v; v = i2bcd( s ); - set_register( addr, v ); + + return ( set_register( addr, v ) ); } -void PCF2127::clear_intr( void ) +int PCF2127::clear_intr( void ) { - set_register( Control_2, 0x00 ); + return ( set_register( Control_2, 0x00 ) ); } -void PCF2127::set_register( char addr, char data ) +int PCF2127::set_register( char addr, char data ) { char b[ 2 ]; b[ 0 ] = addr; b[ 1 ] = data; - i2c.write( device_address, b, 2 ); + return ( i2c.write( device_address, b, 2 ) ); } -char PCF2127::read_register( char addr ) +int PCF2127::read_register( char addr ) { char data;
--- a/PCF2127.h Thu Dec 04 04:58:24 2014 +0000 +++ b/PCF2127.h Tue Dec 09 07:21:13 2014 +0000 @@ -2,8 +2,8 @@ * PCF2127 library * * @author Akifumi (Tedd) OKANO, NXP Semiconductors - * @version 1.5 - * @date 04-Dec-2014 + * @version 1.6 + * @date 09-Dec-2014 * * PCF2127 is a "real time clock (RTC)" module which is including a Xtal and TCXO * http://www.nxp.com/products/interface_and_connectivity/real_time_clocks/rtcs_with_temp_compensation/series/PCF2127.html @@ -54,17 +54,38 @@ Aging_offset } RegisterName; - + + /** Error code */ + typedef enum { + NO_ERROR = 0, + CLOCK_INTEGRITY_FAIL = 1, + I2C_ACCESS_FAIL = 2, + TIME_FUNC_ERROR = ((time_t)-1) + } + ErrorNum; + /** Create a PCF2127 instance connected to specified I2C pins with specified address * * @param I2C_sda I2C-bus SDA pin * @param I2C_scl I2C-bus SCL pin - * @param vControl_1 (option) data for Control_1 register + * @param vControl_1 (option) data for Control_1 register (default setting generates interrupts by second and minute) * @param vControl_2 (option) data for Control_2 register - * @param vControl_3 (option) data for Control_3 register + * @param vControl_3 (option) data for Control_3 register (default setting of battery switch-over function as standard mode) + * @param vCLKOUT_ctl (option) data for CLKOUT_ctl register (default setting 1Hz output on CLKOUT pin) + CLKOUT_ctl */ - PCF2127( PinName sda, PinName sdl, char vControl_1 = 0x03, char vControl_2 = 0x00, char vControl_3 = 0x60 ); + PCF2127( PinName sda, PinName sdl, char vControl_1 = Cntl1, char vControl_2 = Cntl2, char vControl_3 = Cntl1, char vCLKOUT_ctl = ClkOut ); + /** Create a PCF2127 instance connected to specified I2C pins with specified address + * + * @param i2c I2C object (instance) + * @param vControl_1 (option) data for Control_1 register (default setting generates interrupts by second and minute) + * @param vControl_2 (option) data for Control_2 register + * @param vControl_3 (option) data for Control_3 register (default setting of battery switch-over function as standard mode) + * @param vCLKOUT_ctl (option) data for CLKOUT_ctl register (default setting 1Hz output on CLKOUT pin) + */ + PCF2127( I2C &i2c, char vControl_1 = Cntl1, char vControl_2 = Cntl2, char vControl_3 = Cntl1, char vCLKOUT_ctl = ClkOut ); + /** Destractor */ ~PCF2127(); @@ -79,12 +100,18 @@ * * @param dtp Pointer to struct tm */ - void set_time( struct tm *dtp ); + int set_time( struct tm *dtp ); + + /** Set the time + * + * @param tp pointer to time_t + */ + int set_time( time_t *tp ); /** Set the time * @param s String data: The time information should be given in format of "YYYY MM DD HH MM SS" */ - void set_time( char *s ); + int set_time( char *s ); /** Get time of day * @@ -99,22 +126,33 @@ * @param addr Register address * @param Integer data. Converted to BCD before writing inot the register. */ - void set_alarm( char addr, char s ); + int set_alarm( char addr, char s ); /** Clear interrupt flag * * Clears interrupt flags by writing 0x00 into Control_2 register * */ - void clear_intr( void ); + int clear_intr( void ); private: - void set_register( char addr, char data ); - char read_register( char addr ); - char i2bcd( char n ); - char bcd2i( char bcd ); - I2C i2c; + typedef enum { + Cntl1 = 0x03, + Cntl2 = 0x00, + Cntl3 = 0x00, + ClkOut = 0x46 + } + DefaultRegParam; + + int init( char vControl_1, char vControl_2, char vControl_3, char vCLKOUT_ctl ); + int set_register( char addr, char data ); + int read_register( char addr ); + char i2bcd( char n ); + char bcd2i( char bcd ); + + I2C *i2c_p; + I2C &i2c; char device_address; } ;