DS1337 RTC library RTC 55 bytes nvram
Diff: ds1337.cpp
- Revision:
- 0:366fa629ac27
- Child:
- 1:8a0e272ed8e6
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ds1337.cpp Sat Oct 24 20:15:44 2015 +0000 @@ -0,0 +1,71 @@ +#include "ds1337.h" + +#define TIME_LENGTH 8 //Length of buffer needed for time/date + +DS1337::DS1337(PinName sda, PinName scl) : _i2c(sda, scl) +{ + _i2c.frequency(DS1337_I2C_FCY); +} + +void DS1337::time2str(Time * t, char * str) +{ + sprintf(str, "%02d/%02d/%04d-%02d:%02d:%02d",t->tm_mon, t->tm_mday,(t->tm_year+1900), t->tm_hour,t->tm_min,t->tm_sec); +} + +bool DS1337::now(Time * now) +{ + buffer[0] = 0x00; // memory address + + if (_i2c.write(DS1337_ADDR, &buffer[0], 1) != 0) + { + sprintf(err, "RTC command write Failed"); + return false; + } + + if (_i2c.read(DS1337_ADDR, buffer, DS1337_BUFFER_SIZE) != 0) + { + sprintf(err, "RTC buffer read Failed"); + return false; + } + + if (buffer[0] & 0x80) + { + sprintf(err, "Clock Stopped"); + return false; + } + + if (buffer[2] & 0x40) + { + sprintf(err, "12hour not supported"); + return false; + } + + now->tm_sec = bcdToDecimal(buffer[0] & 0x7F); + now->tm_min = bcdToDecimal(buffer[1] & 0x7F); + now->tm_hour = bcdToDecimal(buffer[2] & 0x3F); + now->tm_mday = bcdToDecimal(buffer[4] & 0x3F); + now->tm_mon = bcdToDecimal(buffer[5] & 0x1F); + now->tm_year = bcdToDecimal(buffer[6] & 0xFF); + + return true; +} + +bool DS1337::set_time(Time * now) +{ + buffer[0] = 0x00; // memory address + buffer[1] = decimalToBcd(now->tm_sec) & 0x7F; + buffer[2] = decimalToBcd(now->tm_min) & 0x7F; + buffer[3] = decimalToBcd(now->tm_hour) & 0x3F; // 24-hour format + buffer[4] = now->tm_wday & 0x07; + buffer[5] = decimalToBcd(now->tm_mday) & 0x3F; + buffer[6] = decimalToBcd(now->tm_mon) & 0x1F; + buffer[7] = decimalToBcd(now->tm_year) & 0xFF; + + if (_i2c.write(DS1337_ADDR, buffer, TIME_LENGTH) != 0) + { + sprintf(err, "RTC command write Failed"); + return false; + } + + return true; +}