pax_global_header00006660000000000000000000000064120153002760014506gustar00rootroot0000000000000052 comment=e70ae4d4f0971ae1ac8f89925c8f358c8f24462f MCP79412RTC-0.82/000077500000000000000000000000001201530027600130365ustar00rootroot00000000000000MCP79412RTC-0.82/MCP79412RTC.cpp000066400000000000000000000553261201530027600151540ustar00rootroot00000000000000/*----------------------------------------------------------------------* * MCP79412RTC.cpp - Arduino library for the Microchip MCP79412 * * Real-Time Clock. This library is intended for use with the Arduino * * Time.h library, http://www.arduino.cc/playground/Code/Time * * * * This library is a drop-in replacement for the DS1307RTC.h library * * by Michael Margolis that is supplied with the Arduino Time library * * above. To change from using a DS1307 RTC to an MCP79412 RTC, it is * * only necessary to change the #include statement to include this * * library instead of DS1307RTC.h. * * * * In addition, this library implements functions to support the * * additional features of the MCP79412. * * * * Jack Christensen 29Jul2012 * * * * This work is licensed under the Creative Commons Attribution- * * ShareAlike 3.0 Unported License. To view a copy of this license, * * visit http://creativecommons.org/licenses/by-sa/3.0/ or send a * * letter to Creative Commons, 171 Second Street, Suite 300, * * San Francisco, California, 94105, USA. * *----------------------------------------------------------------------*/ #include #include "MCP79412RTC.h" /*----------------------------------------------------------------------* * Constructor. * *----------------------------------------------------------------------*/ MCP79412RTC::MCP79412RTC() { Wire.begin(); } /*----------------------------------------------------------------------* * Read the current time from the RTC and return it as a time_t value. * *----------------------------------------------------------------------*/ time_t MCP79412RTC::get() { tmElements_t tm; read(tm); return(makeTime(tm)); } /*----------------------------------------------------------------------* * Set the RTC to the given time_t value. * *----------------------------------------------------------------------*/ void MCP79412RTC::set(time_t t) { tmElements_t tm; breakTime(t, tm); write(tm); } /*----------------------------------------------------------------------* * Read the current time from the RTC and return it in a tmElements_t * * structure. * *----------------------------------------------------------------------*/ void MCP79412RTC::read(tmElements_t &tm) { Wire.beginTransmission(RTC_ADDR); i2cWrite(TIME_REG); Wire.endTransmission(); //request 7 bytes (secs, min, hr, dow, date, mth, yr) Wire.requestFrom(RTC_ADDR, tmNbrFields); tm.Second = bcd2dec(i2cRead() & ~_BV(ST)); tm.Minute = bcd2dec(i2cRead()); tm.Hour = bcd2dec(i2cRead() & ~_BV(HR1224)); //assumes 24hr clock tm.Wday = i2cRead() & ~(_BV(OSCON) | _BV(VBAT) | _BV(VBATEN)); //mask off OSCON, VBAT, VBATEN bits tm.Day = bcd2dec(i2cRead()); tm.Month = bcd2dec(i2cRead() & ~_BV(LP)); //mask off the leap year bit tm.Year = y2kYearToTm(bcd2dec(i2cRead())); } /*----------------------------------------------------------------------* * Set the RTC's time from a tmElements_t structure. * *----------------------------------------------------------------------*/ void MCP79412RTC::write(tmElements_t &tm) { Wire.beginTransmission(RTC_ADDR); i2cWrite(TIME_REG); i2cWrite(0x00); //stops the oscillator (Bit 7, ST == 0) i2cWrite(dec2bcd(tm.Minute)); i2cWrite(dec2bcd(tm.Hour)); //sets 24 hour format (Bit 6 == 0) i2cWrite(tm.Wday | _BV(VBATEN)); //enable battery backup operation i2cWrite(dec2bcd(tm.Day)); i2cWrite(dec2bcd(tm.Month)); i2cWrite(dec2bcd(tmYearToY2k(tm.Year))); Wire.endTransmission(); Wire.beginTransmission(RTC_ADDR); i2cWrite(TIME_REG); i2cWrite(dec2bcd(tm.Second) | _BV(ST)); //set the seconds and start the oscillator (Bit 7, ST == 1) Wire.endTransmission(); } /*----------------------------------------------------------------------* * Write a single byte to RTC RAM. * * Valid address range is 0x00 - 0x5F, no checking. * *----------------------------------------------------------------------*/ void MCP79412RTC::ramWrite(byte addr, byte value) { ramWrite(addr, &value, 1); } /*----------------------------------------------------------------------* * Write multiple bytes to RTC RAM. * * Valid address range is 0x00 - 0x5F, no checking. * * Number of bytes (nBytes) must be between 1 and 31 (Wire library * * has a limitation of 31 bytes). * *----------------------------------------------------------------------*/ void MCP79412RTC::ramWrite(byte addr, byte *values, byte nBytes) { Wire.beginTransmission(RTC_ADDR); i2cWrite(addr); for (byte i=0; i= 1 && nBytes <= I2C_BYTE_LIMIT && (addr + nBytes) <= SRAM_SIZE) { ramWrite( (addr & (SRAM_SIZE - 1) ) + SRAM_START_ADDR, values, nBytes ); } } /*----------------------------------------------------------------------* * Read a single byte from Static RAM. * * Address (addr) is constrained to the range (0, 63). * *----------------------------------------------------------------------*/ byte MCP79412RTC::sramRead(byte addr) { byte value; ramRead( (addr & (SRAM_SIZE - 1) ) + SRAM_START_ADDR, &value, 1 ); return value; } /*----------------------------------------------------------------------* * Read multiple bytes from Static RAM. * * Address (addr) is constrained to the range (0, 63). * * Number of bytes (nBytes) must be between 1 and 31 (Wire library * * has a limitation of 31 bytes). * * Invalid values for addr or nBytes, or combinations of addr and * * nBytes that would result in addressing past the last byte of SRAM * * result in no action. * *----------------------------------------------------------------------*/ void MCP79412RTC::sramRead(byte addr, byte *values, byte nBytes) { if (nBytes >= 1 && nBytes <= I2C_BYTE_LIMIT && (addr + nBytes) <= SRAM_SIZE) { ramRead((addr & (SRAM_SIZE - 1) ) + SRAM_START_ADDR, values, nBytes); } } /*----------------------------------------------------------------------* * Write a single byte to EEPROM. * * Address (addr) is constrained to the range (0, 127). * * Can't leverage page write function because a write can't start * * mid-page. * *----------------------------------------------------------------------*/ void MCP79412RTC::eepromWrite(byte addr, byte value) { Wire.beginTransmission(EEPROM_ADDR); i2cWrite( addr & (EEPROM_SIZE - 1) ); i2cWrite(value); Wire.endTransmission(); eepromWait(); } /*----------------------------------------------------------------------* * Write a page (or less) to EEPROM. An EEPROM page is 8 bytes. * * Address (addr) should be a page start address (0, 8, ..., 120), but * * is ruthlessly coerced into a valid value. * * Number of bytes (nBytes) must be between 1 and 8, other values * * result in no action. * *----------------------------------------------------------------------*/ void MCP79412RTC::eepromWrite(byte addr, byte *values, byte nBytes) { if (nBytes >= 1 && nBytes <= EEPROM_PAGE_SIZE) { Wire.beginTransmission(EEPROM_ADDR); i2cWrite( addr & ~(EEPROM_PAGE_SIZE - 1) & (EEPROM_SIZE - 1) ); for (byte i=0; i= 1 && nBytes <= I2C_BYTE_LIMIT && (addr + nBytes) <= EEPROM_SIZE) { Wire.beginTransmission(EEPROM_ADDR); i2cWrite( addr & (EEPROM_SIZE - 1) ); Wire.endTransmission(); Wire.requestFrom( (uint8_t)EEPROM_ADDR, nBytes ); for (byte i=0; i= -127 && value <= 127) { calibVal = abs(value); if (value < 0) calibVal += 128; ramWrite(CALIB_REG, calibVal); } } /*----------------------------------------------------------------------* * Read the unique ID. * * Caller must provide an 8-byte array to contain the results. * *----------------------------------------------------------------------*/ void MCP79412RTC::idRead(byte *uniqueID) { Wire.beginTransmission(EEPROM_ADDR); i2cWrite(UNIQUE_ID_ADDR); Wire.endTransmission(); Wire.requestFrom( EEPROM_ADDR, UNIQUE_ID_SIZE ); for (byte i=0; i *powerUp) { --dn.Year; *powerDown = makeTime(dn); } } else return false; } /*----------------------------------------------------------------------* * Enable or disable the square wave output. * *----------------------------------------------------------------------*/ void MCP79412RTC::squareWave(uint8_t freq) { uint8_t ctrlReg; ramRead(CTRL_REG, &ctrlReg, 1); if (freq > 3) { ctrlReg &= ~_BV(SQWE); } else { ctrlReg = (ctrlReg & 0xF8) | _BV(SQWE) | freq; } ramWrite(CTRL_REG, &ctrlReg, 1); } /*----------------------------------------------------------------------* * Set an alarm time. Sets the alarm registers only, does not enable * * the alarm. See enableAlarm(). * *----------------------------------------------------------------------*/ void MCP79412RTC::setAlarm(uint8_t alarmNumber, time_t alarmTime) { tmElements_t tm; uint8_t day; //need to preserve bits in the day (of week) register alarmNumber &= 0x01; //ensure a valid alarm number ramRead( ALM0_DAY + alarmNumber * (ALM1_REG - ALM0_REG) , &day, 1); breakTime(alarmTime, tm); Wire.beginTransmission(RTC_ADDR); i2cWrite( ALM0_REG + alarmNumber * (ALM1_REG - ALM0_REG) ); i2cWrite(dec2bcd(tm.Second)); i2cWrite(dec2bcd(tm.Minute)); i2cWrite(dec2bcd(tm.Hour)); //sets 24 hour format (Bit 6 == 0) i2cWrite( (day & 0xF8) + tm.Wday ); i2cWrite(dec2bcd(tm.Day)); i2cWrite(dec2bcd(tm.Month)); Wire.endTransmission(); } /*----------------------------------------------------------------------* * Enable or disable an alarm, and set the trigger criteria, * * e.g. match only seconds, only minutes, entire time and date, etc. * *----------------------------------------------------------------------*/ void MCP79412RTC::enableAlarm(uint8_t alarmNumber, uint8_t alarmType) { uint8_t day; //alarm day register has config & flag bits uint8_t ctrl; //control register has alarm enable bits alarmNumber &= 0x01; //ensure a valid alarm number ramRead(CTRL_REG, &ctrl, 1); if (alarmType < ALM_DISABLE) { ramRead(ALM0_DAY + alarmNumber * (ALM1_REG - ALM0_REG), &day, 1); day = ( day & 0x07 ) | alarmType << 4; //reset interrupt flag, OR in the config bits ramWrite(ALM0_DAY + alarmNumber * (ALM1_REG - ALM0_REG), &day, 1); ctrl |= _BV(ALM0 + alarmNumber); //enable the alarm } else { ctrl &= ~(_BV(ALM0 + alarmNumber)); //disable the alarm } ramWrite(CTRL_REG, &ctrl, 1); } /*----------------------------------------------------------------------* * Returns true or false depending on whether the given alarm has been * * triggered, and resets the alarm "interrupt" flag. This is not a real * * interrupt, just a bit that's set when an alarm is triggered. * *----------------------------------------------------------------------*/ boolean MCP79412RTC::alarm(uint8_t alarmNumber) { uint8_t day; //alarm day register has config & flag bits alarmNumber &= 0x01; //ensure a valid alarm number ramRead( ALM0_DAY + alarmNumber * (ALM1_REG - ALM0_REG) , &day, 1); if (day & _BV(ALMIF)) { day &= ~_BV(ALMIF); //turn off the alarm "interrupt" flag ramWrite( ALM0_DAY + alarmNumber * (ALM1_REG - ALM0_REG) , &day, 1); return true; } else return false; } /*----------------------------------------------------------------------* * Check to see if the RTC's oscillator is started (ST bit in seconds * * register). Returns true if started. * *----------------------------------------------------------------------*/ boolean MCP79412RTC::oscStarted(void) { Wire.beginTransmission(RTC_ADDR); i2cWrite(TIME_REG); Wire.endTransmission(); //request just the seconds register Wire.requestFrom(RTC_ADDR, 1); return i2cRead() & _BV(ST); } /*----------------------------------------------------------------------* * Decimal-to-BCD conversion * *----------------------------------------------------------------------*/ uint8_t MCP79412RTC::dec2bcd(uint8_t num) { return ((num / 10 * 16) + (num % 10)); } /*----------------------------------------------------------------------* * BCD-to-Decimal conversion * *----------------------------------------------------------------------*/ uint8_t MCP79412RTC::bcd2dec(uint8_t num) { return ((num / 16 * 10) + (num % 16)); } MCP79412RTC RTC = MCP79412RTC(); //instantiate an RTC object MCP79412RTC-0.82/MCP79412RTC.h000066400000000000000000000153451201530027600146160ustar00rootroot00000000000000/*----------------------------------------------------------------------* * MCP79412RTC.h - Arduino library for the Microchip MCP79412 * * Real-Time Clock. This library is intended for use with the Arduino * * Time.h library, http://www.arduino.cc/playground/Code/Time * * * * This library is a drop-in replacement for the DS1307RTC.h library * * by Michael Margolis that is supplied with the Arduino Time library * * above. To change from using a DS1307 RTC to an MCP79412 RTC, it is * * only necessary to change the #include statement to include this * * library instead of DS1307RTC.h. * * * * In addition, this library implements functions to support the * * additional features of the MCP79412. * * * * Jack Christensen 29Jul2012 * * * * This work is licensed under the Creative Commons Attribution- * * ShareAlike 3.0 Unported License. To view a copy of this license, * * visit http://creativecommons.org/licenses/by-sa/3.0/ or send a * * letter to Creative Commons, 171 Second Street, Suite 300, * * San Francisco, California, 94105, USA. * *----------------------------------------------------------------------*/ #ifndef MCP79412RTC_h #define MCP79412RTC_h #include #if defined(ARDUINO) && ARDUINO >= 100 #include #else #include #endif //define release-independent I2C functions #if ARDUINO >= 100 #define i2cRead Wire.read #define i2cWrite Wire.write #else #define i2cRead Wire.receive #define i2cWrite Wire.send #endif //MCP7941x I2C Addresses #define RTC_ADDR 0x6F #define EEPROM_ADDR 0x57 //MCP7941x Register Addresses #define TIME_REG 0x00 //7 registers, Seconds, Minutes, Hours, DOW, Date, Month, Year #define DAY_REG 0x03 //the RTC Day register contains the OSCON, VBAT, and VBATEN bits #define YEAR_REG 0x06 //RTC year register #define CTRL_REG 0x07 //control register #define CALIB_REG 0x08 //calibration register #define UNLOCK_ID_REG 0x09 //unlock ID register #define ALM0_REG 0x0A //alarm 0, 6 registers, Seconds, Minutes, Hours, DOW, Date, Month #define ALM1_REG 0x11 //alarm 1, 6 registers, Seconds, Minutes, Hours, DOW, Date, Month #define ALM0_DAY 0x0D //DOW register has alarm config/flag bits #define PWRDWN_TS_REG 0x18 //power-down timestamp, 4 registers, Minutes, Hours, Date, Month #define PWRUP_TS_REG 0x1C //power-up timestamp, 4 registers, Minutes, Hours, Date, Month #define TIMESTAMP_SIZE 8 //number of bytes in the two timestamp registers #define SRAM_START_ADDR 0x20 //first SRAM address #define SRAM_SIZE 64 //number of bytes of SRAM #define EEPROM_SIZE 128 //number of bytes of EEPROM #define EEPROM_PAGE_SIZE 8 //number of bytes on an EEPROM page #define I2C_BYTE_LIMIT 31 //Wire library limitation, only 31 data bytes can be transferred. #define UNIQUE_ID_ADDR 0xF0 //starting address for unique ID #define UNIQUE_ID_SIZE 8 //number of bytes in unique ID //Control Register bits #define OUT 7 //sets logic level on MFP when not used as square wave output #define SQWE 6 //set to enable square wave output #define ALM1 5 //alarm 1 is active #define ALM0 4 //alarm 0 is active #define EXTOSC 3 //set to drive the RTC registers from an external oscillator instead of a crystal #define RS2 2 //RS2:0 set square wave output frequency: 0==1Hz, 1==4096Hz, 2==8192Hz, 3=32768Hz #define RS1 1 #define RS0 0 enum {SQWAVE_1_HZ, SQWAVE_4096_HZ, SQWAVE_8192_HZ, SQWAVE_32768_HZ, SQWAVE_NONE}; //Other Control Bits #define ST 7 //Seconds register (TIME_REG) oscillator start/stop bit, 1==Start, 0==Stop #define HR1224 6 //Hours register (TIME_REG+2) 12 or 24 hour mode (24 hour mode==0) #define AMPM 5 //Hours register (TIME_REG+2) AM/PM bit for 12 hour mode #define OSCON 5 //Day register (TIME_REG+3) oscillator running (set and cleared by hardware) #define VBAT 4 //Day register (TIME_REG+3) set by hardware when Vcc fails and RTC runs on battery. //VBAT is cleared by software, clearing VBAT also clears the timestamp registers #define VBATEN 3 //Day register (TIME_REG+3) VBATEN==1 enables backup battery, VBATEN==0 disconnects the VBAT pin (e.g. to save battery) #define LP 5 //Month register (TIME_REG+5) leap year bit //Alarm Control Bits #define ALMPOL 7 //Alarm Polarity: Defines the logic level for the MFP when an alarm is triggered. #define ALMC2 6 //Alarm configuration bits determine how alarms match. See ALM_MATCH defines below. #define ALMC1 5 #define ALMC0 4 #define ALMIF 3 //Alarm Interrupt Flag: Set by hardware when an alarm was triggered, cleared by software. enum {ALM_MATCH_SECONDS, ALM_MATCH_MINUTES, ALM_MATCH_HOURS, ALM_MATCH_DAY, ALM_MATCH_DATE, ALM_RESERVED_5, ALM_RESERVED_6, ALM_MATCH_DATETIME, ALM_DISABLE}; //Note ALM_MATCH_DAY triggers alarm at midnight #define ALARM_0 0 //constants for calling functions #define ALARM_1 1 class MCP79412RTC { public: MCP79412RTC(); static time_t get(void); static void set(time_t t); static void read(tmElements_t &tm); static void write(tmElements_t &tm); void sramWrite(byte addr, byte value); void sramWrite(byte addr, byte *values, byte nBytes); byte sramRead(byte addr); void sramRead(byte addr, byte *values, byte nBytes); void eepromWrite(byte addr, byte value); void eepromWrite(byte addr, byte *values, byte nBytes); byte eepromRead(byte addr); void eepromRead(byte addr, byte *values, byte nBytes); int calibRead(void); void calibWrite(int value); void idRead(byte *uniqueID); boolean powerFail(time_t *powerDown, time_t *powerUp); void squareWave(uint8_t freq); void setAlarm(uint8_t alarmNumber, time_t alarmTime); void enableAlarm(uint8_t alarmNumber, uint8_t alarmType); boolean alarm(uint8_t alarmNumber); boolean oscStarted(void); private: static void ramWrite(byte addr, byte value); static void ramWrite(byte addr, byte *values, byte nBytes); static byte ramRead(byte addr); static void ramRead(byte addr, byte *values, byte nBytes); static byte eepromWait(void); static uint8_t dec2bcd(uint8_t num); static uint8_t bcd2dec(uint8_t num); }; extern MCP79412RTC RTC; #endif MCP79412RTC-0.82/ReadMe.txt000066400000000000000000000120141201530027600147320ustar00rootroot00000000000000/*----------------------------------------------------------------------* * MCP79412RTC.cpp - Arduino library to support the Microchip MCP79412 * * Real-Time Clock. This library is intended for use with the Arduino * * Time.h library, http://www.arduino.cc/playground/Code/Time * * * * This library is a drop-in replacement for the DS1307RTC.h library * * by Michael Margolis that is supplied with the Arduino Time library * * above. To change from using a DS1307 RTC to an MCP79412 RTC, it is * * only necessary to change the #include statement to include * * MCP79412RTC.h instead of DS1307RTC.h. * * * * In addition, this library implements functions to support the * * additional features of the MCP79412. * * * * Jack Christensen 29Jul2012 * * * * This work is licensed under the Creative Commons Attribution- * * ShareAlike 3.0 Unported License. To view a copy of this license, * * visit http://creativecommons.org/licenses/by-sa/3.0/ or send a * * letter to Creative Commons, 171 Second Street, Suite 300, * * San Francisco, California, 94105, USA. * *----------------------------------------------------------------------*/ Alpha Version 0.8 Aug-2012 Currently implemented: Functions to set and read the time from the RTC. Functions to read and write SRAM and EEPROM. Functions to read and write the calibration register and to read the 64-bit ID. Not yet implemented: Alarm functions: Set, read, enable, detect, etc. Functions to read and reset the power fail timestamps. Function(s) to enable and set the CLKOUT frequency. Decent documentation. Example sketches. Brief descriptions of currently implemented functions follow. Read the current time from the RTC and return as a time_t value. time_t get(void); Set the RTC to the given time_t value. void set(time_t t); Read the current time from the RTC and return as a tmElements_t structure. See the Arduino Time library for details on the tmElements_t structure: http://www.arduino.cc/playground/Code/Time. read(tmElements_t &tm); Set the RTC to the time represented in the given tmElements_t structure. void write(tmElements_t &tm); Write a single byte to the RTC static RAM. void sramWrite(byte addr, byte value); Write multiple bytes to the RTC static RAM. nBytes <= 31. values is a byte array, e.g. byte myValues[31]; void sramWrite(byte addr, byte *values, byte nBytes); Read a single byte from the RTC static RAM. byte sramRead(byte addr); Read multiple bytes from the RTC static RAM, place their values into the given array. nBytes <= 31. void sramRead(byte addr, byte *values, byte nBytes); Write a single byte to the RTC EEPROM. void eepromWrite(byte addr, byte value); Write multiple bytes to the RTC EEPROM. nBytes <= 31. values is a byte array, e.g. byte myValues[31]; void eepromWrite(byte addr, byte *values, byte nBytes); Read a single byte from the RTC EEPROM. byte eepromRead(byte addr); Read multiple bytes from the RTC static RAM, place their values into the given array. nBytes <= 31. void eepromRead(byte addr, byte *values, byte nBytes); Returns the value of the RTC calibration register. This is an adjustment factor in PPM, and must be between -127 and 127. int calibRead(void); Write the given value into the RTC calibration register. void calibWrite(int value); Read the 64-bit unique ID from the RTC into the given 8-byte array. void idRead(byte *uniqueID); Returns true or false to indicate whether a power failure has occurred. If one occurred, the power down and power up timestamps are returned in the variables given by the caller, the RTC's power fail flag is reset and the power up/down timestamps are cleared. boolean powerFail(time_t *powerDown, time_t *powerUp); Enables or disables the square wave output on the multi-function pin (MFP). freq is one of the following: SQWAVE_1_HZ, SQWAVE_4096_HZ, SQWAVE_8192_HZ, SQWAVE_32768_HZ, SQWAVE_NONE void squareWave(uint8_t freq); Set an alarm time. Sets the alarm registers only, does not enable the alarm, use enableAlarm() for that. alarmNumber is 0 or 1, but is ruthlessly masked to ensure this is so. void setAlarm(uint8_t alarmNumber, time_t alarmTime); Enable or disable the given alarm (0 or 1). alarmNumber is masked to ensure a value of 0 or 1. alarmType is one of the following: ALM_MATCH_SECONDS, ALM_MATCH_MINUTES, ALM_MATCH_HOURS, ALM_MATCH_DAY, ALM_MATCH_DATE, ALM_MATCH_DATETIME, ALM_DISABLE void enableAlarm(uint8_t alarmNumber, uint8_t alarmType); Tests whether the given alarm (0 or 1) has been triggered, returns true if triggered, else false. Clears the alarm flag to trap the next trigger event can be trapped. boolean alarm(uint8_t alarmNumber);