Kevin Braun / ds3232m

Library for Maxim DS3232M super-accurate, I2C based Real Time Clock chip with 234 bytes of user RAM. Library includes user RAM read/write operations along with CRC routines for accessing the user RAM area.

Dependents:   ds3232m_HelloWorld

ds3232m.cpp@6:968b8efe3ca0, 2016-03-11 (annotated)

Committer:
loopsva
Date:
Fri Mar 11 18:09:54 2016 +0000
Revision:
6:968b8efe3ca0
Parent:
2:a9a8027a7cb2 
Changed things around.  Moved RTCbuffer to data structure. Added CRC saved & calculated data to data structure.  Put more requirements on the calling program.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
loopsva 0:30a7faf58768 1 #include "mbed.h"
loopsva 0:30a7faf58768 2 #include "ds3232m.h"
loopsva 0:30a7faf58768 3
loopsva 6:968b8efe3ca0 4 #define RTCI2CADDRESS 0xd0 //i2c address of the DS3232M
loopsva 6:968b8efe3ca0 5 #define DS3232SECONDS 0x00 //seconds register
loopsva 6:968b8efe3ca0 6 #define DS3232DAYOFWEEK 0x03 //day of the week register
loopsva 6:968b8efe3ca0 7 #define DS3232ALM1BOTTOM 0x07 //alarm 1 registers (not used)
loopsva 6:968b8efe3ca0 8 #define DS3232ALM2BOTTOM 0x0b //alarm 2 registers (not used)
loopsva 6:968b8efe3ca0 9 #define DS3232CTLREG 0x0e //control register
loopsva 6:968b8efe3ca0 10 #define DS3232STATREG 0x0f //status register
loopsva 6:968b8efe3ca0 11 #define DS3232TEMPERATURE 0x11 //temperature registers
loopsva 6:968b8efe3ca0 12 #define DS3232TESTREG 0x13 //test register (do not use)
loopsva 6:968b8efe3ca0 13 #define DS3232RAMBOTTOM 0x14 //where user RAM starts
loopsva 6:968b8efe3ca0 14 #define DS3232RAMCRC16 0xfc //crc16 registers (top 2 bytes of user RAM)
loopsva 6:968b8efe3ca0 15 #define DS3232RAMTOP 0xfe //where user RAM ends. Note: bug in F746 only allows for a I2C xfer of 255 max!!!!
loopsva 6:968b8efe3ca0 16
loopsva 0:30a7faf58768 17 //control register
loopsva 6:968b8efe3ca0 18 #define DS3232_EOSCN_BIT 0x80 //turn on/off oscillator in batt backup mode, 0 = on
loopsva 6:968b8efe3ca0 19 #define DS3232_BBSQW_BIT 0x40 //battery backed 1Hz enable, 1 = enable
loopsva 6:968b8efe3ca0 20 #define DS3232_CONV_BIT 0x20 //start temperature conversion, 1 = start
loopsva 6:968b8efe3ca0 21 #define DS3232_INTCN_BIT 0x04 //interrupt control, 1 = interrupt mode, 0 = 1Hz mode
loopsva 6:968b8efe3ca0 22
loopsva 0:30a7faf58768 23 //status register
loopsva 6:968b8efe3ca0 24 #define DS3232_OSF_BIT 0x80 //oscillator stopped, 1 = stopped
loopsva 6:968b8efe3ca0 25 #define DS3232_BB32KHZ_BIT 0x40 //battery backed 32KHz enable, 1 = enable(writable bit)
loopsva 6:968b8efe3ca0 26 #define DS3232_EN32KHZ_BIT 0x08 //32KHz enable, 1 = enable(writable bit)
loopsva 6:968b8efe3ca0 27 #define DS3232_BUSY_BIT 0x04 //busy doing a temperature A:D conversion, 1 = busy
loopsva 0:30a7faf58768 28
loopsva 6:968b8efe3ca0 29 char RtcCtlReg = 0; //mirror of control register
loopsva 6:968b8efe3ca0 30 char RtcStatReg = 0; //mirror of status register
loopsva 6:968b8efe3ca0 31
loopsva 6:968b8efe3ca0 32 //char RTCbuffer[256]; //buffer may contain up to 256 bytes, depending on command used
loopsva 0:30a7faf58768 33
loopsva 0:30a7faf58768 34 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 35 // constructor with fixed frequency
loopsva 0:30a7faf58768 36
loopsva 0:30a7faf58768 37 ds3232m::ds3232m(PinName sda, PinName scl) {
loopsva 0:30a7faf58768 38 // Create a new I2C object
loopsva 0:30a7faf58768 39 _i2c_ = new I2C(sda, scl);
loopsva 0:30a7faf58768 40 // Set the frequency to standard 400kHz
loopsva 0:30a7faf58768 41 _i2c_->frequency(400000);
loopsva 0:30a7faf58768 42 }
loopsva 0:30a7faf58768 43
loopsva 0:30a7faf58768 44 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 45 // constructor with I2C frequency selection
loopsva 0:30a7faf58768 46
loopsva 0:30a7faf58768 47 ds3232m::ds3232m(PinName sda, PinName scl, int i2cFrequency) {
loopsva 0:30a7faf58768 48 _i2c_ = new I2C(sda, scl);
loopsva 0:30a7faf58768 49 _i2c_->frequency(i2cFrequency);
loopsva 0:30a7faf58768 50 }
loopsva 0:30a7faf58768 51
loopsva 0:30a7faf58768 52 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 53 // deconstructor
loopsva 0:30a7faf58768 54
loopsva 0:30a7faf58768 55 ds3232m::~ds3232m() {
loopsva 0:30a7faf58768 56 }
loopsva 0:30a7faf58768 57
loopsva 0:30a7faf58768 58 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 59 // set time up into the DS3232M
loopsva 0:30a7faf58768 60
loopsva 6:968b8efe3ca0 61 void ds3232m::setTime(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 62 dsSTR.RTCbuffer[0] = DS3232SECONDS;
loopsva 6:968b8efe3ca0 63 dsSTR.RTCbuffer[1] = DecToBCD(dsSTR.sec);
loopsva 6:968b8efe3ca0 64 dsSTR.RTCbuffer[2] = DecToBCD(dsSTR.min);
loopsva 6:968b8efe3ca0 65 dsSTR.RTCbuffer[3] = DecToBCD(dsSTR.hour);
loopsva 6:968b8efe3ca0 66 dsSTR.RTCbuffer[4] = dsSTR.wday;
loopsva 6:968b8efe3ca0 67 dsSTR.RTCbuffer[5] = DecToBCD(dsSTR.date);
loopsva 6:968b8efe3ca0 68 dsSTR.RTCbuffer[6] = DecToBCD(dsSTR.mon);
loopsva 6:968b8efe3ca0 69 dsSTR.RTCbuffer[7] = DecToBCD(dsSTR.year - 2000);
loopsva 2:a9a8027a7cb2 70
loopsva 6:968b8efe3ca0 71 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 8, false);
loopsva 0:30a7faf58768 72 }
loopsva 0:30a7faf58768 73
loopsva 0:30a7faf58768 74 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 75 // get time from the DS3232M and stick it into the mbed's RTC
loopsva 0:30a7faf58768 76
loopsva 6:968b8efe3ca0 77 void ds3232m::getTime(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 78 dsSTR.RTCbuffer[0] = DS3232SECONDS;
loopsva 6:968b8efe3ca0 79 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, true);
loopsva 6:968b8efe3ca0 80 _i2c_->read(RTCI2CADDRESS, dsSTR.RTCbuffer, 7, false);
loopsva 0:30a7faf58768 81
loopsva 6:968b8efe3ca0 82 dsSTR.sec = BCDToDec(dsSTR.RTCbuffer[0]);
loopsva 6:968b8efe3ca0 83 dsSTR.min = BCDToDec(dsSTR.RTCbuffer[1]);
loopsva 6:968b8efe3ca0 84 dsSTR.hour = ds3232m::BCDToDec(dsSTR.RTCbuffer[2]);
loopsva 6:968b8efe3ca0 85 dsSTR.wday = dsSTR.RTCbuffer[3];
loopsva 6:968b8efe3ca0 86 dsSTR.date = ds3232m::BCDToDec(dsSTR.RTCbuffer[4]);
loopsva 6:968b8efe3ca0 87 dsSTR.mon = ds3232m::BCDToDec(dsSTR.RTCbuffer[5]);
loopsva 6:968b8efe3ca0 88 dsSTR.year = ds3232m::BCDToDec(dsSTR.RTCbuffer[6]) + 2000;
loopsva 0:30a7faf58768 89 }
loopsva 0:30a7faf58768 90
loopsva 0:30a7faf58768 91 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 92 // retrieve the control and status registers
loopsva 0:30a7faf58768 93
loopsva 6:968b8efe3ca0 94 void ds3232m::getControlStatusRegs(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 95 dsSTR.RTCbuffer[0] = DS3232CTLREG;
loopsva 6:968b8efe3ca0 96 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, true);
loopsva 6:968b8efe3ca0 97 _i2c_->read(RTCI2CADDRESS, dsSTR.RTCbuffer, 2, false);
loopsva 6:968b8efe3ca0 98 RtcCtlReg = dsSTR.RTCbuffer[0];
loopsva 6:968b8efe3ca0 99 RtcStatReg = dsSTR.RTCbuffer[1];
loopsva 0:30a7faf58768 100 }
loopsva 0:30a7faf58768 101
loopsva 0:30a7faf58768 102 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 103 // enables/disables the main oscillator during battery backup mode. true = enable during battery backup mode
loopsva 0:30a7faf58768 104
loopsva 6:968b8efe3ca0 105 void ds3232m::enableBattClock(Time_rtc& dsSTR, bool batt) {
loopsva 6:968b8efe3ca0 106 getControlStatusRegs(dsSTR);
loopsva 0:30a7faf58768 107 if(batt == true) {
loopsva 0:30a7faf58768 108 RtcCtlReg &= ~DS3232_EOSCN_BIT;
loopsva 0:30a7faf58768 109 } else {
loopsva 0:30a7faf58768 110 RtcCtlReg |= DS3232_EOSCN_BIT;
loopsva 0:30a7faf58768 111 }
loopsva 6:968b8efe3ca0 112
loopsva 6:968b8efe3ca0 113 dsSTR.RTCbuffer[0] = DS3232CTLREG;
loopsva 6:968b8efe3ca0 114 dsSTR.RTCbuffer[1] = RtcCtlReg;
loopsva 6:968b8efe3ca0 115 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 2, false);
loopsva 0:30a7faf58768 116 }
loopsva 0:30a7faf58768 117
loopsva 0:30a7faf58768 118 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 119 // check to see if DS3232M's temperature conversion cycle is bust or not
loopsva 0:30a7faf58768 120 // only 1 per second max
loopsva 0:30a7faf58768 121
loopsva 6:968b8efe3ca0 122 bool ds3232m::checkTempBusy(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 123 getControlStatusRegs(dsSTR);
loopsva 0:30a7faf58768 124 if(RtcCtlReg & DS3232_CONV_BIT) return true; //is already busy
loopsva 0:30a7faf58768 125 if(RtcStatReg & DS3232_BUSY_BIT) return true; //is already busy
loopsva 0:30a7faf58768 126 return false;
loopsva 0:30a7faf58768 127 }
loopsva 0:30a7faf58768 128
loopsva 0:30a7faf58768 129 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 130 // start a temperature conversion cycle
loopsva 0:30a7faf58768 131 // only 1 per second max
loopsva 0:30a7faf58768 132
loopsva 6:968b8efe3ca0 133 bool ds3232m::startTempCycle(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 134 getControlStatusRegs(dsSTR);
loopsva 6:968b8efe3ca0 135 if((checkTempBusy(dsSTR)) == true) return false; //is already busy
loopsva 0:30a7faf58768 136 RtcCtlReg |= DS3232_CONV_BIT;
loopsva 2:a9a8027a7cb2 137
loopsva 6:968b8efe3ca0 138 dsSTR.RTCbuffer[0] = DS3232CTLREG;
loopsva 6:968b8efe3ca0 139 dsSTR.RTCbuffer[1] = RtcCtlReg;
loopsva 6:968b8efe3ca0 140 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 2, false);
loopsva 0:30a7faf58768 141 return true;
loopsva 0:30a7faf58768 142 }
loopsva 0:30a7faf58768 143
loopsva 0:30a7faf58768 144 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 145 // get temperature
loopsva 0:30a7faf58768 146 // if returned value = 255.0, then temperature conversion was still busy
loopsva 0:30a7faf58768 147
loopsva 6:968b8efe3ca0 148 float ds3232m::getTemperature(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 149 getControlStatusRegs(dsSTR);
loopsva 6:968b8efe3ca0 150 if((checkTempBusy(dsSTR)) == false) return(255.0); //is already busy
loopsva 1:0975d4a9b513 151
loopsva 6:968b8efe3ca0 152 dsSTR.RTCbuffer[0] = DS3232TEMPERATURE;
loopsva 6:968b8efe3ca0 153 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, true);
loopsva 6:968b8efe3ca0 154 _i2c_->read(RTCI2CADDRESS, dsSTR.RTCbuffer, 2, false);
loopsva 6:968b8efe3ca0 155 int8_t temp3232a = dsSTR.RTCbuffer[0];
loopsva 6:968b8efe3ca0 156 uint8_t temp3232b = dsSTR.RTCbuffer[1];
loopsva 6:968b8efe3ca0 157
loopsva 6:968b8efe3ca0 158 float temp3232 = (float)temp3232a;
loopsva 0:30a7faf58768 159 //for positive temp
loopsva 0:30a7faf58768 160 if((temp3232b == 0x40) && (temp3232a >= 0)) temp3232 += 0.25;
loopsva 0:30a7faf58768 161 if (temp3232b == 0x80) temp3232 += 0.5;
loopsva 0:30a7faf58768 162 if((temp3232b == 0xc0) && (temp3232a >= 0)) temp3232 += 0.75;
loopsva 0:30a7faf58768 163 //for negative temp
loopsva 0:30a7faf58768 164 if((temp3232b == 0x40) && (temp3232a < 0)) temp3232 += 0.75;
loopsva 0:30a7faf58768 165 if((temp3232b == 0xc0) && (temp3232a < 0)) temp3232 += 0.25;
loopsva 0:30a7faf58768 166 return (temp3232);
loopsva 0:30a7faf58768 167 }
loopsva 0:30a7faf58768 168
loopsva 0:30a7faf58768 169 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 170 // get seconds register
loopsva 0:30a7faf58768 171
loopsva 6:968b8efe3ca0 172 uint8_t ds3232m::getSeconds(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 173 dsSTR.RTCbuffer[0] = DS3232SECONDS;
loopsva 6:968b8efe3ca0 174 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, true);
loopsva 6:968b8efe3ca0 175 _i2c_->read(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, false);
loopsva 6:968b8efe3ca0 176 int seconds3232 = dsSTR.RTCbuffer[0];
loopsva 0:30a7faf58768 177 int xbcd = BCDToDec(seconds3232);
loopsva 0:30a7faf58768 178 return(xbcd);
loopsva 0:30a7faf58768 179 }
loopsva 0:30a7faf58768 180
loopsva 0:30a7faf58768 181 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 6:968b8efe3ca0 182 // get day of the week register (1 = Monday... 7 = Sunday)
loopsva 6:968b8efe3ca0 183
loopsva 6:968b8efe3ca0 184 uint8_t ds3232m::getDayOfWeek(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 185 dsSTR.RTCbuffer[0] = DS3232DAYOFWEEK;
loopsva 6:968b8efe3ca0 186 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, true);
loopsva 6:968b8efe3ca0 187 _i2c_->read(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, false);
loopsva 6:968b8efe3ca0 188 int dow3232 = dsSTR.RTCbuffer[0];
loopsva 6:968b8efe3ca0 189 return(BCDToDec(dow3232));
loopsva 6:968b8efe3ca0 190 }
loopsva 6:968b8efe3ca0 191
loopsva 6:968b8efe3ca0 192 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 6:968b8efe3ca0 193 // set day of the week register (1 = Monday... 7 = Sunday)
loopsva 6:968b8efe3ca0 194
loopsva 6:968b8efe3ca0 195 void ds3232m::putDayOfWeek(Time_rtc& dsSTR, uint8_t dow3232) {
loopsva 6:968b8efe3ca0 196 dow3232 = dow3232 & 7;
loopsva 6:968b8efe3ca0 197 dsSTR.RTCbuffer[0] = DS3232DAYOFWEEK;
loopsva 6:968b8efe3ca0 198 dsSTR.RTCbuffer[1] = DecToBCD(dow3232);
loopsva 6:968b8efe3ca0 199 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 2, false);
loopsva 6:968b8efe3ca0 200 }
loopsva 6:968b8efe3ca0 201
loopsva 6:968b8efe3ca0 202 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 203 // clears all user memory inside the DS3232M. Top 2 locations - reserved for CRC, also set to 00 since CRC value is 0x00 0x00
loopsva 0:30a7faf58768 204
loopsva 6:968b8efe3ca0 205 void ds3232m::clearRAM(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 206 for(int i = DS3232SECONDS; i <= DS3232RAMTOP; i++) dsSTR.RTCbuffer[i] = 0;
loopsva 6:968b8efe3ca0 207 dsSTR.RTCbuffer[0] = DS3232RAMBOTTOM;
loopsva 6:968b8efe3ca0 208 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, (DS3232RAMTOP - DS3232RAMBOTTOM + 2), false);
loopsva 0:30a7faf58768 209 }
loopsva 0:30a7faf58768 210
loopsva 0:30a7faf58768 211 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 212 // retrieves user data from DS3232M RAM
loopsva 0:30a7faf58768 213
loopsva 6:968b8efe3ca0 214 uint8_t ds3232m::getUserRAM(char *buffer, Time_rtc& dsSTR, int offset, int length) {
loopsva 6:968b8efe3ca0 215 if((offset + length) > DS3232RAMCRC16) return(DS3232_OVERFLOWERROR);
loopsva 6:968b8efe3ca0 216 if(offset < DS3232RAMBOTTOM) return(DS3232_OFFSETERROR);
loopsva 6:968b8efe3ca0 217 if(length == 0) return(DS3232_LENZEROERROR);
loopsva 6:968b8efe3ca0 218 dsSTR.RTCbuffer[0] = offset;
loopsva 6:968b8efe3ca0 219 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, true);
loopsva 6:968b8efe3ca0 220 _i2c_->read(RTCI2CADDRESS, buffer, length, false);
loopsva 6:968b8efe3ca0 221 if(LoadRTCRam(dsSTR) == false) return(DS3232_CRCERROR);
loopsva 6:968b8efe3ca0 222 return(DS3232_NOERROR);
loopsva 0:30a7faf58768 223 }
loopsva 0:30a7faf58768 224
loopsva 0:30a7faf58768 225 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 226 // puts user data into DS3232M RAM. CRC16 value added to the top 2 RAM location
loopsva 0:30a7faf58768 227
loopsva 6:968b8efe3ca0 228 uint8_t ds3232m::putUserRAM(char *buffer, Time_rtc& dsSTR, int offset, int length) {
loopsva 6:968b8efe3ca0 229 if((offset + length) > DS3232RAMCRC16) return(DS3232_OVERFLOWERROR);
loopsva 6:968b8efe3ca0 230 if(offset < DS3232RAMBOTTOM) return(DS3232_OFFSETERROR);
loopsva 6:968b8efe3ca0 231 if(length == 0) return(DS3232_LENZEROERROR);
loopsva 6:968b8efe3ca0 232 for(int i = 0; i < 32; i++) dsSTR.RTCbuffer[i] = NULL;
loopsva 6:968b8efe3ca0 233 dsSTR.RTCbuffer[0] = offset;
loopsva 6:968b8efe3ca0 234 dsSTR.RTCbuffer[1] = NULL;
loopsva 6:968b8efe3ca0 235 strcat(dsSTR.RTCbuffer, buffer);
loopsva 6:968b8efe3ca0 236 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, length + 1, false);
loopsva 6:968b8efe3ca0 237 addCRC16(dsSTR);
loopsva 6:968b8efe3ca0 238 return(DS3232_NOERROR);
loopsva 0:30a7faf58768 239 }
loopsva 0:30a7faf58768 240
loopsva 0:30a7faf58768 241 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 242 // enable/disable 32KHz output with run on battery mode option
loopsva 0:30a7faf58768 243
loopsva 6:968b8efe3ca0 244 void ds3232m::set32KhzOutput(Time_rtc& dsSTR, bool ena, bool batt) {
loopsva 6:968b8efe3ca0 245 getControlStatusRegs(dsSTR);
loopsva 0:30a7faf58768 246 if(ena == true) {
loopsva 0:30a7faf58768 247 RtcStatReg |= DS3232_EN32KHZ_BIT;
loopsva 0:30a7faf58768 248 if(batt == true) {
loopsva 0:30a7faf58768 249 RtcStatReg |= DS3232_BB32KHZ_BIT;
loopsva 0:30a7faf58768 250 } else {
loopsva 0:30a7faf58768 251 RtcStatReg &= ~DS3232_BB32KHZ_BIT;
loopsva 0:30a7faf58768 252 }
loopsva 0:30a7faf58768 253 } else {
loopsva 0:30a7faf58768 254 RtcStatReg &= ~DS3232_EN32KHZ_BIT;
loopsva 0:30a7faf58768 255 RtcStatReg &= ~DS3232_BB32KHZ_BIT;
loopsva 0:30a7faf58768 256 }
loopsva 2:a9a8027a7cb2 257
loopsva 6:968b8efe3ca0 258 dsSTR.RTCbuffer[0] = DS3232STATREG;
loopsva 6:968b8efe3ca0 259 dsSTR.RTCbuffer[1] = RtcStatReg;
loopsva 6:968b8efe3ca0 260 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 2, false);
loopsva 0:30a7faf58768 261 }
loopsva 0:30a7faf58768 262
loopsva 0:30a7faf58768 263 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 264 // enable/disable 1Hz output with run on battery mode option
loopsva 0:30a7faf58768 265
loopsva 6:968b8efe3ca0 266 void ds3232m::set1hzOutput(Time_rtc& dsSTR, bool ena, bool batt) {
loopsva 6:968b8efe3ca0 267 getControlStatusRegs(dsSTR);
loopsva 0:30a7faf58768 268 if(ena == true) {
loopsva 0:30a7faf58768 269 RtcCtlReg &= ~DS3232_INTCN_BIT;
loopsva 0:30a7faf58768 270 if(batt == true) {
loopsva 0:30a7faf58768 271 RtcCtlReg |= DS3232_BBSQW_BIT;
loopsva 0:30a7faf58768 272 } else {
loopsva 0:30a7faf58768 273 RtcCtlReg &= ~DS3232_BBSQW_BIT;
loopsva 0:30a7faf58768 274 }
loopsva 0:30a7faf58768 275 } else {
loopsva 0:30a7faf58768 276 RtcCtlReg |= DS3232_INTCN_BIT;
loopsva 0:30a7faf58768 277 RtcCtlReg &= ~DS3232_BBSQW_BIT;
loopsva 0:30a7faf58768 278 }
loopsva 2:a9a8027a7cb2 279
loopsva 6:968b8efe3ca0 280 dsSTR.RTCbuffer[0] = DS3232CTLREG;
loopsva 6:968b8efe3ca0 281 dsSTR.RTCbuffer[1] = RtcCtlReg;
loopsva 6:968b8efe3ca0 282 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 2, false);
loopsva 0:30a7faf58768 283 }
loopsva 0:30a7faf58768 284
loopsva 0:30a7faf58768 285 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 286 // CRC table and routine taken from Emilie Laverge's CRC16 library
loopsva 0:30a7faf58768 287 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 288 // lookup table for calculating crc16
loopsva 0:30a7faf58768 289
loopsva 0:30a7faf58768 290 uint16_t crc16table[256] = {
loopsva 0:30a7faf58768 291 0x0000, 0x8005, 0x800F, 0x000A, 0x801B, 0x001E, 0x0014, 0x8011,
loopsva 0:30a7faf58768 292 0x8033, 0x0036, 0x003C, 0x8039, 0x0028, 0x802D, 0x8027, 0x0022,
loopsva 0:30a7faf58768 293 0x8063, 0x0066, 0x006C, 0x8069, 0x0078, 0x807D, 0x8077, 0x0072,
loopsva 0:30a7faf58768 294 0x0050, 0x8055, 0x805F, 0x005A, 0x804B, 0x004E, 0x0044, 0x8041,
loopsva 0:30a7faf58768 295 0x80C3, 0x00C6, 0x00CC, 0x80C9, 0x00D8, 0x80DD, 0x80D7, 0x00D2,
loopsva 0:30a7faf58768 296 0x00F0, 0x80F5, 0x80FF, 0x00FA, 0x80EB, 0x00EE, 0x00E4, 0x80E1,
loopsva 0:30a7faf58768 297 0x00A0, 0x80A5, 0x80AF, 0x00AA, 0x80BB, 0x00BE, 0x00B4, 0x80B1,
loopsva 0:30a7faf58768 298 0x8093, 0x0096, 0x009C, 0x8099, 0x0088, 0x808D, 0x8087, 0x0082,
loopsva 0:30a7faf58768 299 0x8183, 0x0186, 0x018C, 0x8189, 0x0198, 0x819D, 0x8197, 0x0192,
loopsva 0:30a7faf58768 300 0x01B0, 0x81B5, 0x81BF, 0x01BA, 0x81AB, 0x01AE, 0x01A4, 0x81A1,
loopsva 0:30a7faf58768 301 0x01E0, 0x81E5, 0x81EF, 0x01EA, 0x81FB, 0x01FE, 0x01F4, 0x81F1,
loopsva 0:30a7faf58768 302 0x81D3, 0x01D6, 0x01DC, 0x81D9, 0x01C8, 0x81CD, 0x81C7, 0x01C2,
loopsva 0:30a7faf58768 303 0x0140, 0x8145, 0x814F, 0x014A, 0x815B, 0x015E, 0x0154, 0x8151,
loopsva 0:30a7faf58768 304 0x8173, 0x0176, 0x017C, 0x8179, 0x0168, 0x816D, 0x8167, 0x0162,
loopsva 0:30a7faf58768 305 0x8123, 0x0126, 0x012C, 0x8129, 0x0138, 0x813D, 0x8137, 0x0132,
loopsva 0:30a7faf58768 306 0x0110, 0x8115, 0x811F, 0x011A, 0x810B, 0x010E, 0x0104, 0x8101,
loopsva 0:30a7faf58768 307 0x8303, 0x0306, 0x030C, 0x8309, 0x0318, 0x831D, 0x8317, 0x0312,
loopsva 0:30a7faf58768 308 0x0330, 0x8335, 0x833F, 0x033A, 0x832B, 0x032E, 0x0324, 0x8321,
loopsva 0:30a7faf58768 309 0x0360, 0x8365, 0x836F, 0x036A, 0x837B, 0x037E, 0x0374, 0x8371,
loopsva 0:30a7faf58768 310 0x8353, 0x0356, 0x035C, 0x8359, 0x0348, 0x834D, 0x8347, 0x0342,
loopsva 0:30a7faf58768 311 0x03C0, 0x83C5, 0x83CF, 0x03CA, 0x83DB, 0x03DE, 0x03D4, 0x83D1,
loopsva 0:30a7faf58768 312 0x83F3, 0x03F6, 0x03FC, 0x83F9, 0x03E8, 0x83ED, 0x83E7, 0x03E2,
loopsva 0:30a7faf58768 313 0x83A3, 0x03A6, 0x03AC, 0x83A9, 0x03B8, 0x83BD, 0x83B7, 0x03B2,
loopsva 0:30a7faf58768 314 0x0390, 0x8395, 0x839F, 0x039A, 0x838B, 0x038E, 0x0384, 0x8381,
loopsva 0:30a7faf58768 315 0x0280, 0x8285, 0x828F, 0x028A, 0x829B, 0x029E, 0x0294, 0x8291,
loopsva 0:30a7faf58768 316 0x82B3, 0x02B6, 0x02BC, 0x82B9, 0x02A8, 0x82AD, 0x82A7, 0x02A2,
loopsva 0:30a7faf58768 317 0x82E3, 0x02E6, 0x02EC, 0x82E9, 0x02F8, 0x82FD, 0x82F7, 0x02F2,
loopsva 0:30a7faf58768 318 0x02D0, 0x82D5, 0x82DF, 0x02DA, 0x82CB, 0x02CE, 0x02C4, 0x82C1,
loopsva 0:30a7faf58768 319 0x8243, 0x0246, 0x024C, 0x8249, 0x0258, 0x825D, 0x8257, 0x0252,
loopsva 0:30a7faf58768 320 0x0270, 0x8275, 0x827F, 0x027A, 0x826B, 0x026E, 0x0264, 0x8261,
loopsva 0:30a7faf58768 321 0x0220, 0x8225, 0x822F, 0x022A, 0x823B, 0x023E, 0x0234, 0x8231,
loopsva 0:30a7faf58768 322 0x8213, 0x0216, 0x021C, 0x8219, 0x0208, 0x820D, 0x8207, 0x0202
loopsva 0:30a7faf58768 323 };
loopsva 0:30a7faf58768 324
loopsva 0:30a7faf58768 325 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 326 // calculate a crc value for the DS3232M user ram area. CRC value calculated from address 0x14 - 0xfd
loopsva 0:30a7faf58768 327
loopsva 6:968b8efe3ca0 328 uint16_t ds3232m::calculateCRC16(char input[], Time_rtc& dsSTR, int offset, int length) {
loopsva 0:30a7faf58768 329 uint16_t CRC16s = 0;
loopsva 0:30a7faf58768 330 input+= offset;
loopsva 0:30a7faf58768 331 for(int i = offset; i < (length + offset); i++) {
loopsva 0:30a7faf58768 332 uint16_t tableValue = crc16table[((CRC16s >> 8) ^ *(char *)input++) & 0x00ff];
loopsva 0:30a7faf58768 333 CRC16s = (CRC16s << 8) ^ tableValue;
loopsva 0:30a7faf58768 334 }
loopsva 6:968b8efe3ca0 335 dsSTR.c_crc = CRC16s;
loopsva 0:30a7faf58768 336 return CRC16s;
loopsva 0:30a7faf58768 337 }
loopsva 0:30a7faf58768 338
loopsva 0:30a7faf58768 339 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 340 // This function gets the entire contents of the RTC. Returns flase if a CRC error occured
loopsva 0:30a7faf58768 341
loopsva 6:968b8efe3ca0 342 bool ds3232m::LoadRTCRam(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 343 dsSTR.RTCbuffer[0] = DS3232SECONDS;
loopsva 6:968b8efe3ca0 344 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, true);
loopsva 6:968b8efe3ca0 345 _i2c_->read(RTCI2CADDRESS, dsSTR.RTCbuffer, DS3232RAMTOP, false); //BUG in F746 only allows for xfer of 255 bytes max!!!
loopsva 0:30a7faf58768 346
loopsva 6:968b8efe3ca0 347 dsSTR.s_crc = (dsSTR.RTCbuffer[DS3232RAMCRC16] << 8) | dsSTR.RTCbuffer[DS3232RAMCRC16 + 1];
loopsva 6:968b8efe3ca0 348 calculateCRC16(dsSTR.RTCbuffer, dsSTR, DS3232RAMBOTTOM, (DS3232RAMCRC16 - DS3232RAMBOTTOM));
loopsva 6:968b8efe3ca0 349
loopsva 6:968b8efe3ca0 350 ////reload the time registers
loopsva 6:968b8efe3ca0 351 //dsSTR.RTCbuffer[0] = DS3232SECONDS;
loopsva 6:968b8efe3ca0 352 //_i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 1, true);
loopsva 6:968b8efe3ca0 353 //_i2c_->read(RTCI2CADDRESS, dsSTR.RTCbuffer, 7, false);
loopsva 2:a9a8027a7cb2 354
loopsva 6:968b8efe3ca0 355 if(dsSTR.c_crc != dsSTR.s_crc) return false;
loopsva 0:30a7faf58768 356 return true;
loopsva 0:30a7faf58768 357 }
loopsva 0:30a7faf58768 358
loopsva 0:30a7faf58768 359 //--------------------------------------------------------------------------------------------------------------------------------------//
loopsva 0:30a7faf58768 360 // This function calculates and saves CRC data to the end of RTC's RAM.
loopsva 0:30a7faf58768 361 // CRC calculated address range is 0x14 - 0xfd. CRC data is placed in 0xfe and 0xff
loopsva 0:30a7faf58768 362
loopsva 6:968b8efe3ca0 363 void ds3232m::addCRC16(Time_rtc& dsSTR) {
loopsva 6:968b8efe3ca0 364 LoadRTCRam(dsSTR);
loopsva 6:968b8efe3ca0 365 dsSTR.c_crc = calculateCRC16(dsSTR.RTCbuffer, dsSTR, DS3232RAMBOTTOM, (DS3232RAMCRC16 - DS3232RAMBOTTOM)); //0x14 is offset from 0 in buffer, 230 is length //
loopsva 6:968b8efe3ca0 366 dsSTR.RTCbuffer[0] = DS3232RAMCRC16;
loopsva 6:968b8efe3ca0 367 dsSTR.RTCbuffer[1] = dsSTR.c_crc >> 8;
loopsva 6:968b8efe3ca0 368 dsSTR.RTCbuffer[2] = dsSTR.c_crc & 0xff;
loopsva 6:968b8efe3ca0 369 _i2c_->write(RTCI2CADDRESS, dsSTR.RTCbuffer, 3, false);
loopsva 0:30a7faf58768 370 }
loopsva 1:0975d4a9b513 371