Two new libraries today: DS3231 and MCP4725
DS3231:
The DS3231 is another extremely accurate RTC according to Dallas/Maxim. This is also the RTC used on the ChronoDot.
It is much more accurate than the DS130x RTCs, and it does not require an external crystal/oscillator.
MCP4725:
The MCP4725 is a low-power, high accuracy, single channel, buffered voltage output 12-bit Digital-to-Analog Convertor (DAC) with non-volatile memory (EEPROM). Its on-board precision output amplifier allows it to achieve rail-to-rail analog output.
Both libraries are available for both Arduino and chipKit.
DS3231:
The DS3231 is another extremely accurate RTC according to Dallas/Maxim. This is also the RTC used on the ChronoDot.
It is much more accurate than the DS130x RTCs, and it does not require an external crystal/oscillator.
MCP4725:
The MCP4725 is a low-power, high accuracy, single channel, buffered voltage output 12-bit Digital-to-Analog Convertor (DAC) with non-volatile memory (EEPROM). Its on-board precision output amplifier allows it to achieve rail-to-rail analog output.
Both libraries are available for both Arduino and chipKit.