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@0:30a7faf58768, 2014-12-08 (annotated)
- Committer:
- loopsva
- Date:
- Mon Dec 08 20:15:16 2014 +0000
- Revision:
- 0:30a7faf58768
- Child:
- 1:0975d4a9b513
Library for Maxim DS3232M super-accurate Real Time Clock with user RAM. Operates on I2C bus.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
loopsva | 0:30a7faf58768 | 1 | #include "mbed.h" |
loopsva | 0:30a7faf58768 | 2 | #include "ds3232m.h" |
loopsva | 0:30a7faf58768 | 3 | |
loopsva | 0:30a7faf58768 | 4 | #define RTCI2CADDRESS 0xd0 |
loopsva | 0:30a7faf58768 | 5 | #define DS3232SECONDS 0x00 |
loopsva | 0:30a7faf58768 | 6 | #define DS3232DAYOFWEEK 0x03 |
loopsva | 0:30a7faf58768 | 7 | #define DS3232ALM1BOTTOM 0x07 |
loopsva | 0:30a7faf58768 | 8 | #define DS3232ALM2BOTTOM 0x0b |
loopsva | 0:30a7faf58768 | 9 | #define DS3232CTLREG 0x0e |
loopsva | 0:30a7faf58768 | 10 | #define DS3232STATREG 0x0f |
loopsva | 0:30a7faf58768 | 11 | #define DS3232TEMPERATURE 0x11 |
loopsva | 0:30a7faf58768 | 12 | #define DS3232TESTREG 0x13 |
loopsva | 0:30a7faf58768 | 13 | #define DS3232RAMBOTTOM 0x14 |
loopsva | 0:30a7faf58768 | 14 | #define DS3232RAMCRC16 0xfe |
loopsva | 0:30a7faf58768 | 15 | //control register |
loopsva | 0:30a7faf58768 | 16 | #define DS3232_EOSCN_BIT 0x80 //turn on/off oscillator in batt backup mode, 0 = on |
loopsva | 0:30a7faf58768 | 17 | #define DS3232_BBSQW_BIT 0x40 //battery backed 1Hz enable, 1 = enable |
loopsva | 0:30a7faf58768 | 18 | #define DS3232_CONV_BIT 0x20 //start temperature conversion, 1 = start |
loopsva | 0:30a7faf58768 | 19 | #define DS3232_INTCN_BIT 0x04 //interrupt control, 1 = interrupt mode, 0 = 1Hz mode |
loopsva | 0:30a7faf58768 | 20 | //status register |
loopsva | 0:30a7faf58768 | 21 | #define DS3232_OSF_BIT 0x80 //oscillator stopped, 1 = stopped |
loopsva | 0:30a7faf58768 | 22 | #define DS3232_BB32KHZ_BIT 0x40 //battery backed 32KHz enable, 1 = enable(writable bit) |
loopsva | 0:30a7faf58768 | 23 | #define DS3232_EN32KHZ_BIT 0x08 //32KHz enable, 1 = enable(writable bit) |
loopsva | 0:30a7faf58768 | 24 | #define DS3232_BUSY_BIT 0x04 //busy doing a temperature A:D conversion, 1 = busy |
loopsva | 0:30a7faf58768 | 25 | |
loopsva | 0:30a7faf58768 | 26 | char RtcCtlReg = 0; |
loopsva | 0:30a7faf58768 | 27 | char RtcStatReg = 0; |
loopsva | 0:30a7faf58768 | 28 | |
loopsva | 0:30a7faf58768 | 29 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 30 | // constructor with fixed frequency |
loopsva | 0:30a7faf58768 | 31 | |
loopsva | 0:30a7faf58768 | 32 | ds3232m::ds3232m(PinName sda, PinName scl) { |
loopsva | 0:30a7faf58768 | 33 | // Create a new I2C object |
loopsva | 0:30a7faf58768 | 34 | _i2c_ = new I2C(sda, scl); |
loopsva | 0:30a7faf58768 | 35 | // Set the frequency to standard 400kHz |
loopsva | 0:30a7faf58768 | 36 | _i2c_->frequency(400000); |
loopsva | 0:30a7faf58768 | 37 | } |
loopsva | 0:30a7faf58768 | 38 | |
loopsva | 0:30a7faf58768 | 39 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 40 | // constructor with I2C frequency selection |
loopsva | 0:30a7faf58768 | 41 | |
loopsva | 0:30a7faf58768 | 42 | ds3232m::ds3232m(PinName sda, PinName scl, int i2cFrequency) { |
loopsva | 0:30a7faf58768 | 43 | _i2c_ = new I2C(sda, scl); |
loopsva | 0:30a7faf58768 | 44 | _i2c_->frequency(i2cFrequency); |
loopsva | 0:30a7faf58768 | 45 | } |
loopsva | 0:30a7faf58768 | 46 | |
loopsva | 0:30a7faf58768 | 47 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 48 | // deconstructor |
loopsva | 0:30a7faf58768 | 49 | |
loopsva | 0:30a7faf58768 | 50 | ds3232m::~ds3232m() { |
loopsva | 0:30a7faf58768 | 51 | } |
loopsva | 0:30a7faf58768 | 52 | |
loopsva | 0:30a7faf58768 | 53 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 54 | // set time up into the DS3232M |
loopsva | 0:30a7faf58768 | 55 | |
loopsva | 0:30a7faf58768 | 56 | void ds3232m::setTime(Time_rtc& time) { |
loopsva | 0:30a7faf58768 | 57 | char buffer[7]; |
loopsva | 0:30a7faf58768 | 58 | buffer[0] = DecToBCD(time.sec); |
loopsva | 0:30a7faf58768 | 59 | buffer[1] = DecToBCD(time.min); |
loopsva | 0:30a7faf58768 | 60 | buffer[2] = DecToBCD(time.hour); |
loopsva | 0:30a7faf58768 | 61 | buffer[3] = time.wday; |
loopsva | 0:30a7faf58768 | 62 | buffer[4] = DecToBCD(time.date); |
loopsva | 0:30a7faf58768 | 63 | buffer[5] = DecToBCD(time.mon); |
loopsva | 0:30a7faf58768 | 64 | buffer[6] = DecToBCD(time.year - 2000); |
loopsva | 0:30a7faf58768 | 65 | |
loopsva | 0:30a7faf58768 | 66 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 67 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 68 | _i2c_->write(DS3232SECONDS); |
loopsva | 0:30a7faf58768 | 69 | for(int i = 0; i < 7; i++) _i2c_->write(buffer[i]); |
loopsva | 0:30a7faf58768 | 70 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 71 | } |
loopsva | 0:30a7faf58768 | 72 | |
loopsva | 0:30a7faf58768 | 73 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 74 | // get time from the DS3232M and stick it into the mbed's RTC |
loopsva | 0:30a7faf58768 | 75 | |
loopsva | 0:30a7faf58768 | 76 | void ds3232m::getTime(Time_rtc& time) { |
loopsva | 0:30a7faf58768 | 77 | char buffer[7]; |
loopsva | 0:30a7faf58768 | 78 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 79 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 80 | _i2c_->write(DS3232SECONDS); |
loopsva | 0:30a7faf58768 | 81 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 82 | _i2c_->write(RTCI2CADDRESS + 1); |
loopsva | 0:30a7faf58768 | 83 | for(int i = 0; i < 7; i++) buffer[i] = _i2c_->read(1); |
loopsva | 0:30a7faf58768 | 84 | int rtcgarbage = (_i2c_->read(0)); //final junk read |
loopsva | 0:30a7faf58768 | 85 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 86 | |
loopsva | 0:30a7faf58768 | 87 | time.sec = BCDToDec(buffer[0]); |
loopsva | 0:30a7faf58768 | 88 | time.min = BCDToDec(buffer[1]); |
loopsva | 0:30a7faf58768 | 89 | time.hour = ds3232m::BCDToDec(buffer[2]); |
loopsva | 0:30a7faf58768 | 90 | time.wday = buffer[3]; |
loopsva | 0:30a7faf58768 | 91 | time.date = ds3232m::BCDToDec(buffer[4]); |
loopsva | 0:30a7faf58768 | 92 | time.mon = ds3232m::BCDToDec(buffer[5]); |
loopsva | 0:30a7faf58768 | 93 | time.year = ds3232m::BCDToDec(buffer[6]) + 2000; // plus hundred is because RTC is giving the years since 2000, but std c struct tm needs years since 1900 |
loopsva | 0:30a7faf58768 | 94 | } |
loopsva | 0:30a7faf58768 | 95 | |
loopsva | 0:30a7faf58768 | 96 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 97 | // retrieve the control and status registers |
loopsva | 0:30a7faf58768 | 98 | |
loopsva | 0:30a7faf58768 | 99 | void ds3232m::getControlStatusRegs() { |
loopsva | 0:30a7faf58768 | 100 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 101 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 102 | _i2c_->write(DS3232CTLREG); |
loopsva | 0:30a7faf58768 | 103 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 104 | _i2c_->write(RTCI2CADDRESS + 1); |
loopsva | 0:30a7faf58768 | 105 | RtcCtlReg = _i2c_->read(1); |
loopsva | 0:30a7faf58768 | 106 | RtcStatReg = _i2c_->read(0); |
loopsva | 0:30a7faf58768 | 107 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 108 | } |
loopsva | 0:30a7faf58768 | 109 | |
loopsva | 0:30a7faf58768 | 110 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 111 | // enables/disables the main oscillator during battery backup mode. true = enable during battery backup mode |
loopsva | 0:30a7faf58768 | 112 | |
loopsva | 0:30a7faf58768 | 113 | void ds3232m::enableBattClock(bool batt) { |
loopsva | 0:30a7faf58768 | 114 | getControlStatusRegs(); |
loopsva | 0:30a7faf58768 | 115 | if(batt == true) { |
loopsva | 0:30a7faf58768 | 116 | RtcCtlReg &= ~DS3232_EOSCN_BIT; |
loopsva | 0:30a7faf58768 | 117 | } else { |
loopsva | 0:30a7faf58768 | 118 | RtcCtlReg |= DS3232_EOSCN_BIT; |
loopsva | 0:30a7faf58768 | 119 | } |
loopsva | 0:30a7faf58768 | 120 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 121 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 122 | _i2c_->write(DS3232CTLREG); |
loopsva | 0:30a7faf58768 | 123 | _i2c_->write(RtcCtlReg); |
loopsva | 0:30a7faf58768 | 124 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 125 | } |
loopsva | 0:30a7faf58768 | 126 | |
loopsva | 0:30a7faf58768 | 127 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 128 | // check to see if DS3232M's temperature conversion cycle is bust or not |
loopsva | 0:30a7faf58768 | 129 | // only 1 per second max |
loopsva | 0:30a7faf58768 | 130 | |
loopsva | 0:30a7faf58768 | 131 | bool ds3232m::checkTempBusy() { |
loopsva | 0:30a7faf58768 | 132 | getControlStatusRegs(); |
loopsva | 0:30a7faf58768 | 133 | if(RtcCtlReg & DS3232_CONV_BIT) return true; //is already busy |
loopsva | 0:30a7faf58768 | 134 | if(RtcStatReg & DS3232_BUSY_BIT) return true; //is already busy |
loopsva | 0:30a7faf58768 | 135 | return false; |
loopsva | 0:30a7faf58768 | 136 | } |
loopsva | 0:30a7faf58768 | 137 | |
loopsva | 0:30a7faf58768 | 138 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 139 | // start a temperature conversion cycle |
loopsva | 0:30a7faf58768 | 140 | // only 1 per second max |
loopsva | 0:30a7faf58768 | 141 | |
loopsva | 0:30a7faf58768 | 142 | bool ds3232m::startTempCycle() { |
loopsva | 0:30a7faf58768 | 143 | getControlStatusRegs(); |
loopsva | 0:30a7faf58768 | 144 | if((checkTempBusy()) == true) return false; //is already busy |
loopsva | 0:30a7faf58768 | 145 | RtcCtlReg |= DS3232_CONV_BIT; |
loopsva | 0:30a7faf58768 | 146 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 147 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 148 | _i2c_->write(DS3232CTLREG); |
loopsva | 0:30a7faf58768 | 149 | _i2c_->write(RtcCtlReg); |
loopsva | 0:30a7faf58768 | 150 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 151 | return true; |
loopsva | 0:30a7faf58768 | 152 | } |
loopsva | 0:30a7faf58768 | 153 | |
loopsva | 0:30a7faf58768 | 154 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 155 | // get temperature |
loopsva | 0:30a7faf58768 | 156 | // if returned value = 255.0, then temperature conversion was still busy |
loopsva | 0:30a7faf58768 | 157 | |
loopsva | 0:30a7faf58768 | 158 | float ds3232m::getTemperature() { |
loopsva | 0:30a7faf58768 | 159 | getControlStatusRegs(); |
loopsva | 0:30a7faf58768 | 160 | if((checkTempBusy()) == false) return(255.0); //is already busy |
loopsva | 0:30a7faf58768 | 161 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 162 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 163 | _i2c_->write(DS3232TEMPERATURE); |
loopsva | 0:30a7faf58768 | 164 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 165 | _i2c_->write(RTCI2CADDRESS + 1); |
loopsva | 0:30a7faf58768 | 166 | int8_t temp3232a = (_i2c_->read(1)); |
loopsva | 0:30a7faf58768 | 167 | uint8_t temp3232b = _i2c_->read(0); |
loopsva | 0:30a7faf58768 | 168 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 169 | float temp3232 = float(temp3232a); |
loopsva | 0:30a7faf58768 | 170 | //for positive temp |
loopsva | 0:30a7faf58768 | 171 | if((temp3232b == 0x40) && (temp3232a >= 0)) temp3232 += 0.25; |
loopsva | 0:30a7faf58768 | 172 | if (temp3232b == 0x80) temp3232 += 0.5; |
loopsva | 0:30a7faf58768 | 173 | if((temp3232b == 0xc0) && (temp3232a >= 0)) temp3232 += 0.75; |
loopsva | 0:30a7faf58768 | 174 | //for negative temp |
loopsva | 0:30a7faf58768 | 175 | if((temp3232b == 0x40) && (temp3232a < 0)) temp3232 += 0.75; |
loopsva | 0:30a7faf58768 | 176 | if((temp3232b == 0xc0) && (temp3232a < 0)) temp3232 += 0.25; |
loopsva | 0:30a7faf58768 | 177 | return (temp3232); |
loopsva | 0:30a7faf58768 | 178 | } |
loopsva | 0:30a7faf58768 | 179 | |
loopsva | 0:30a7faf58768 | 180 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 181 | // get seconds register |
loopsva | 0:30a7faf58768 | 182 | |
loopsva | 0:30a7faf58768 | 183 | int ds3232m::getSeconds() { |
loopsva | 0:30a7faf58768 | 184 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 185 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 186 | _i2c_->write(DS3232SECONDS); |
loopsva | 0:30a7faf58768 | 187 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 188 | _i2c_->write(RTCI2CADDRESS + 1); |
loopsva | 0:30a7faf58768 | 189 | int seconds3232 = (_i2c_->read(0)); |
loopsva | 0:30a7faf58768 | 190 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 191 | int xbcd = BCDToDec(seconds3232); |
loopsva | 0:30a7faf58768 | 192 | return(xbcd); |
loopsva | 0:30a7faf58768 | 193 | } |
loopsva | 0:30a7faf58768 | 194 | |
loopsva | 0:30a7faf58768 | 195 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 196 | // 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 | 197 | |
loopsva | 0:30a7faf58768 | 198 | void ds3232m::clearRAM() { |
loopsva | 0:30a7faf58768 | 199 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 200 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 201 | _i2c_->write(DS3232RAMBOTTOM); |
loopsva | 0:30a7faf58768 | 202 | for(int i = DS3232RAMBOTTOM; i < 256; i++) _i2c_->write(NULL); |
loopsva | 0:30a7faf58768 | 203 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 204 | } |
loopsva | 0:30a7faf58768 | 205 | |
loopsva | 0:30a7faf58768 | 206 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 207 | // retrieves user data from DS3232M RAM |
loopsva | 0:30a7faf58768 | 208 | // returns 00 = ok |
loopsva | 0:30a7faf58768 | 209 | // returns 01 = length + offset is over the highest user RAM location |
loopsva | 0:30a7faf58768 | 210 | // returns 02 = offset < 0x14 |
loopsva | 0:30a7faf58768 | 211 | // returns 04 = length = 0 |
loopsva | 0:30a7faf58768 | 212 | // returns 08 = crc error |
loopsva | 0:30a7faf58768 | 213 | |
loopsva | 0:30a7faf58768 | 214 | int ds3232m::getUserRAM(char *buffer, int offset, int length) { |
loopsva | 0:30a7faf58768 | 215 | if((offset + length) > 0xfe) return(1); |
loopsva | 0:30a7faf58768 | 216 | if(offset < 0x14) return(2); |
loopsva | 0:30a7faf58768 | 217 | if(length == 0) return(4); |
loopsva | 0:30a7faf58768 | 218 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 219 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 220 | _i2c_->write(offset); |
loopsva | 0:30a7faf58768 | 221 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 222 | _i2c_->write(RTCI2CADDRESS + 1); |
loopsva | 0:30a7faf58768 | 223 | for(int i = 0; i < length; i++) buffer[i] = _i2c_->read(1); |
loopsva | 0:30a7faf58768 | 224 | _i2c_->read(0); |
loopsva | 0:30a7faf58768 | 225 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 226 | if(LoadRTCRam() == false) return(8); |
loopsva | 0:30a7faf58768 | 227 | return(0); |
loopsva | 0:30a7faf58768 | 228 | } |
loopsva | 0:30a7faf58768 | 229 | |
loopsva | 0:30a7faf58768 | 230 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 231 | // puts user data into DS3232M RAM. CRC16 value added to the top 2 RAM location |
loopsva | 0:30a7faf58768 | 232 | // returns 00 = ok |
loopsva | 0:30a7faf58768 | 233 | // returns 01 = length + offset is over the highest user RAM location |
loopsva | 0:30a7faf58768 | 234 | // returns 02 = offset < 0x14 |
loopsva | 0:30a7faf58768 | 235 | // returns 04 = length = 0 |
loopsva | 0:30a7faf58768 | 236 | |
loopsva | 0:30a7faf58768 | 237 | int ds3232m::putUserRAM(char *buffer, int offset, int length) { |
loopsva | 0:30a7faf58768 | 238 | if((offset + length) > 0xfe) return(1); |
loopsva | 0:30a7faf58768 | 239 | if(offset < 0x14) return(2); |
loopsva | 0:30a7faf58768 | 240 | if(length == 0) return(4); |
loopsva | 0:30a7faf58768 | 241 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 242 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 243 | _i2c_->write(offset); |
loopsva | 0:30a7faf58768 | 244 | for(int i = 0; i < length; i++) _i2c_->write(buffer[i]); |
loopsva | 0:30a7faf58768 | 245 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 246 | addCRC16(); |
loopsva | 0:30a7faf58768 | 247 | return(0); |
loopsva | 0:30a7faf58768 | 248 | } |
loopsva | 0:30a7faf58768 | 249 | |
loopsva | 0:30a7faf58768 | 250 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 251 | // enable/disable 32KHz output with run on battery mode option |
loopsva | 0:30a7faf58768 | 252 | |
loopsva | 0:30a7faf58768 | 253 | void ds3232m::set32KhzOutput(bool ena, bool batt) { |
loopsva | 0:30a7faf58768 | 254 | getControlStatusRegs(); |
loopsva | 0:30a7faf58768 | 255 | if(ena == true) { |
loopsva | 0:30a7faf58768 | 256 | RtcStatReg |= DS3232_EN32KHZ_BIT; |
loopsva | 0:30a7faf58768 | 257 | if(batt == true) { |
loopsva | 0:30a7faf58768 | 258 | RtcStatReg |= DS3232_BB32KHZ_BIT; |
loopsva | 0:30a7faf58768 | 259 | } else { |
loopsva | 0:30a7faf58768 | 260 | RtcStatReg &= ~DS3232_BB32KHZ_BIT; |
loopsva | 0:30a7faf58768 | 261 | } |
loopsva | 0:30a7faf58768 | 262 | } else { |
loopsva | 0:30a7faf58768 | 263 | RtcStatReg &= ~DS3232_EN32KHZ_BIT; |
loopsva | 0:30a7faf58768 | 264 | RtcStatReg &= ~DS3232_BB32KHZ_BIT; |
loopsva | 0:30a7faf58768 | 265 | } |
loopsva | 0:30a7faf58768 | 266 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 267 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 268 | _i2c_->write(DS3232STATREG); |
loopsva | 0:30a7faf58768 | 269 | _i2c_->write(RtcStatReg); |
loopsva | 0:30a7faf58768 | 270 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 271 | } |
loopsva | 0:30a7faf58768 | 272 | |
loopsva | 0:30a7faf58768 | 273 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 274 | // enable/disable 1Hz output with run on battery mode option |
loopsva | 0:30a7faf58768 | 275 | |
loopsva | 0:30a7faf58768 | 276 | void ds3232m::set1hzOutput(bool ena, bool batt) { |
loopsva | 0:30a7faf58768 | 277 | getControlStatusRegs(); |
loopsva | 0:30a7faf58768 | 278 | if(ena == true) { |
loopsva | 0:30a7faf58768 | 279 | RtcCtlReg &= ~DS3232_INTCN_BIT; |
loopsva | 0:30a7faf58768 | 280 | if(batt == true) { |
loopsva | 0:30a7faf58768 | 281 | RtcCtlReg |= DS3232_BBSQW_BIT; |
loopsva | 0:30a7faf58768 | 282 | } else { |
loopsva | 0:30a7faf58768 | 283 | RtcCtlReg &= ~DS3232_BBSQW_BIT; |
loopsva | 0:30a7faf58768 | 284 | } |
loopsva | 0:30a7faf58768 | 285 | } else { |
loopsva | 0:30a7faf58768 | 286 | RtcCtlReg |= DS3232_INTCN_BIT; |
loopsva | 0:30a7faf58768 | 287 | RtcCtlReg &= ~DS3232_BBSQW_BIT; |
loopsva | 0:30a7faf58768 | 288 | } |
loopsva | 0:30a7faf58768 | 289 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 290 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 291 | _i2c_->write(DS3232CTLREG); |
loopsva | 0:30a7faf58768 | 292 | _i2c_->write(RtcCtlReg); |
loopsva | 0:30a7faf58768 | 293 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 294 | } |
loopsva | 0:30a7faf58768 | 295 | |
loopsva | 0:30a7faf58768 | 296 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 297 | // CRC table and routine taken from Emilie Laverge's CRC16 library |
loopsva | 0:30a7faf58768 | 298 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 299 | // lookup table for calculating crc16 |
loopsva | 0:30a7faf58768 | 300 | |
loopsva | 0:30a7faf58768 | 301 | uint16_t crc16table[256] = { |
loopsva | 0:30a7faf58768 | 302 | 0x0000, 0x8005, 0x800F, 0x000A, 0x801B, 0x001E, 0x0014, 0x8011, |
loopsva | 0:30a7faf58768 | 303 | 0x8033, 0x0036, 0x003C, 0x8039, 0x0028, 0x802D, 0x8027, 0x0022, |
loopsva | 0:30a7faf58768 | 304 | 0x8063, 0x0066, 0x006C, 0x8069, 0x0078, 0x807D, 0x8077, 0x0072, |
loopsva | 0:30a7faf58768 | 305 | 0x0050, 0x8055, 0x805F, 0x005A, 0x804B, 0x004E, 0x0044, 0x8041, |
loopsva | 0:30a7faf58768 | 306 | 0x80C3, 0x00C6, 0x00CC, 0x80C9, 0x00D8, 0x80DD, 0x80D7, 0x00D2, |
loopsva | 0:30a7faf58768 | 307 | 0x00F0, 0x80F5, 0x80FF, 0x00FA, 0x80EB, 0x00EE, 0x00E4, 0x80E1, |
loopsva | 0:30a7faf58768 | 308 | 0x00A0, 0x80A5, 0x80AF, 0x00AA, 0x80BB, 0x00BE, 0x00B4, 0x80B1, |
loopsva | 0:30a7faf58768 | 309 | 0x8093, 0x0096, 0x009C, 0x8099, 0x0088, 0x808D, 0x8087, 0x0082, |
loopsva | 0:30a7faf58768 | 310 | 0x8183, 0x0186, 0x018C, 0x8189, 0x0198, 0x819D, 0x8197, 0x0192, |
loopsva | 0:30a7faf58768 | 311 | 0x01B0, 0x81B5, 0x81BF, 0x01BA, 0x81AB, 0x01AE, 0x01A4, 0x81A1, |
loopsva | 0:30a7faf58768 | 312 | 0x01E0, 0x81E5, 0x81EF, 0x01EA, 0x81FB, 0x01FE, 0x01F4, 0x81F1, |
loopsva | 0:30a7faf58768 | 313 | 0x81D3, 0x01D6, 0x01DC, 0x81D9, 0x01C8, 0x81CD, 0x81C7, 0x01C2, |
loopsva | 0:30a7faf58768 | 314 | 0x0140, 0x8145, 0x814F, 0x014A, 0x815B, 0x015E, 0x0154, 0x8151, |
loopsva | 0:30a7faf58768 | 315 | 0x8173, 0x0176, 0x017C, 0x8179, 0x0168, 0x816D, 0x8167, 0x0162, |
loopsva | 0:30a7faf58768 | 316 | 0x8123, 0x0126, 0x012C, 0x8129, 0x0138, 0x813D, 0x8137, 0x0132, |
loopsva | 0:30a7faf58768 | 317 | 0x0110, 0x8115, 0x811F, 0x011A, 0x810B, 0x010E, 0x0104, 0x8101, |
loopsva | 0:30a7faf58768 | 318 | 0x8303, 0x0306, 0x030C, 0x8309, 0x0318, 0x831D, 0x8317, 0x0312, |
loopsva | 0:30a7faf58768 | 319 | 0x0330, 0x8335, 0x833F, 0x033A, 0x832B, 0x032E, 0x0324, 0x8321, |
loopsva | 0:30a7faf58768 | 320 | 0x0360, 0x8365, 0x836F, 0x036A, 0x837B, 0x037E, 0x0374, 0x8371, |
loopsva | 0:30a7faf58768 | 321 | 0x8353, 0x0356, 0x035C, 0x8359, 0x0348, 0x834D, 0x8347, 0x0342, |
loopsva | 0:30a7faf58768 | 322 | 0x03C0, 0x83C5, 0x83CF, 0x03CA, 0x83DB, 0x03DE, 0x03D4, 0x83D1, |
loopsva | 0:30a7faf58768 | 323 | 0x83F3, 0x03F6, 0x03FC, 0x83F9, 0x03E8, 0x83ED, 0x83E7, 0x03E2, |
loopsva | 0:30a7faf58768 | 324 | 0x83A3, 0x03A6, 0x03AC, 0x83A9, 0x03B8, 0x83BD, 0x83B7, 0x03B2, |
loopsva | 0:30a7faf58768 | 325 | 0x0390, 0x8395, 0x839F, 0x039A, 0x838B, 0x038E, 0x0384, 0x8381, |
loopsva | 0:30a7faf58768 | 326 | 0x0280, 0x8285, 0x828F, 0x028A, 0x829B, 0x029E, 0x0294, 0x8291, |
loopsva | 0:30a7faf58768 | 327 | 0x82B3, 0x02B6, 0x02BC, 0x82B9, 0x02A8, 0x82AD, 0x82A7, 0x02A2, |
loopsva | 0:30a7faf58768 | 328 | 0x82E3, 0x02E6, 0x02EC, 0x82E9, 0x02F8, 0x82FD, 0x82F7, 0x02F2, |
loopsva | 0:30a7faf58768 | 329 | 0x02D0, 0x82D5, 0x82DF, 0x02DA, 0x82CB, 0x02CE, 0x02C4, 0x82C1, |
loopsva | 0:30a7faf58768 | 330 | 0x8243, 0x0246, 0x024C, 0x8249, 0x0258, 0x825D, 0x8257, 0x0252, |
loopsva | 0:30a7faf58768 | 331 | 0x0270, 0x8275, 0x827F, 0x027A, 0x826B, 0x026E, 0x0264, 0x8261, |
loopsva | 0:30a7faf58768 | 332 | 0x0220, 0x8225, 0x822F, 0x022A, 0x823B, 0x023E, 0x0234, 0x8231, |
loopsva | 0:30a7faf58768 | 333 | 0x8213, 0x0216, 0x021C, 0x8219, 0x0208, 0x820D, 0x8207, 0x0202 |
loopsva | 0:30a7faf58768 | 334 | }; |
loopsva | 0:30a7faf58768 | 335 | |
loopsva | 0:30a7faf58768 | 336 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 337 | // calculate a crc value for the DS3232M user ram area. CRC value calculated from address 0x14 - 0xfd |
loopsva | 0:30a7faf58768 | 338 | |
loopsva | 0:30a7faf58768 | 339 | uint16_t ds3232m::calculateCRC16(char input[], int offset, int length) { |
loopsva | 0:30a7faf58768 | 340 | uint16_t CRC16s = 0; |
loopsva | 0:30a7faf58768 | 341 | input+= offset; |
loopsva | 0:30a7faf58768 | 342 | for(int i = offset; i < (length + offset); i++) { |
loopsva | 0:30a7faf58768 | 343 | uint16_t tableValue = crc16table[((CRC16s >> 8) ^ *(char *)input++) & 0x00ff]; |
loopsva | 0:30a7faf58768 | 344 | CRC16s = (CRC16s << 8) ^ tableValue; |
loopsva | 0:30a7faf58768 | 345 | } |
loopsva | 0:30a7faf58768 | 346 | return CRC16s; |
loopsva | 0:30a7faf58768 | 347 | } |
loopsva | 0:30a7faf58768 | 348 | |
loopsva | 0:30a7faf58768 | 349 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 350 | // This function gets the entire contents of the RTC. Returns flase if a CRC error occured |
loopsva | 0:30a7faf58768 | 351 | |
loopsva | 0:30a7faf58768 | 352 | char RTCbuffer[256]; |
loopsva | 0:30a7faf58768 | 353 | |
loopsva | 0:30a7faf58768 | 354 | bool ds3232m::LoadRTCRam() { |
loopsva | 0:30a7faf58768 | 355 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 356 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 357 | _i2c_->write(0x00); |
loopsva | 0:30a7faf58768 | 358 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 359 | _i2c_->write(RTCI2CADDRESS + 1); |
loopsva | 0:30a7faf58768 | 360 | int i = 0; |
loopsva | 0:30a7faf58768 | 361 | for(i = 0; i < 255; i++) { |
loopsva | 0:30a7faf58768 | 362 | RTCbuffer[i] = _i2c_->read(1); |
loopsva | 0:30a7faf58768 | 363 | } |
loopsva | 0:30a7faf58768 | 364 | RTCbuffer[i] = _i2c_->read(0); |
loopsva | 0:30a7faf58768 | 365 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 366 | uint16_t calcdCRC = calculateCRC16(RTCbuffer, DS3232RAMBOTTOM, (DS3232RAMCRC16 - DS3232RAMBOTTOM)); |
loopsva | 0:30a7faf58768 | 367 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 368 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 369 | _i2c_->write(DS3232RAMCRC16); |
loopsva | 0:30a7faf58768 | 370 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 371 | _i2c_->write(RTCI2CADDRESS + 1); |
loopsva | 0:30a7faf58768 | 372 | uint16_t storedCRC = (_i2c_->read(1) << 8) + (_i2c_->read(0) & 0xff); |
loopsva | 0:30a7faf58768 | 373 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 374 | if(storedCRC != calcdCRC) return false; |
loopsva | 0:30a7faf58768 | 375 | return true; |
loopsva | 0:30a7faf58768 | 376 | } |
loopsva | 0:30a7faf58768 | 377 | |
loopsva | 0:30a7faf58768 | 378 | //--------------------------------------------------------------------------------------------------------------------------------------// |
loopsva | 0:30a7faf58768 | 379 | // This function calculates and saves CRC data to the end of RTC's RAM. |
loopsva | 0:30a7faf58768 | 380 | // CRC calculated address range is 0x14 - 0xfd. CRC data is placed in 0xfe and 0xff |
loopsva | 0:30a7faf58768 | 381 | |
loopsva | 0:30a7faf58768 | 382 | void ds3232m::addCRC16() { |
loopsva | 0:30a7faf58768 | 383 | LoadRTCRam(); |
loopsva | 0:30a7faf58768 | 384 | uint16_t resultCRC = calculateCRC16(RTCbuffer, DS3232RAMBOTTOM, (DS3232RAMCRC16 - DS3232RAMBOTTOM)); //0x14 is offset from 0 in buffer, 230 is length // |
loopsva | 0:30a7faf58768 | 385 | _i2c_->start(); |
loopsva | 0:30a7faf58768 | 386 | _i2c_->write(RTCI2CADDRESS); |
loopsva | 0:30a7faf58768 | 387 | _i2c_->write(DS3232RAMCRC16); |
loopsva | 0:30a7faf58768 | 388 | _i2c_->write(resultCRC >> 8); |
loopsva | 0:30a7faf58768 | 389 | _i2c_->write(resultCRC & 0xff); |
loopsva | 0:30a7faf58768 | 390 | _i2c_->stop(); |
loopsva | 0:30a7faf58768 | 391 | } |