Embedded Programming with Modern C++ Cookbook

How it works...

We are implementing an application that talks directly to the hardware RTC connected to the system. There is a difference between the system clock and the RTC. The system clock is active and maintained only when the system is running. When the system is powered off or goes into sleep mode, the system clock becomes invalid. The RTC is active even when the system is off. It maintains the actual time that is used to configure the system clock when the system is up. Moreover, it can be programmed to wake up the system at a specific time when in sleep mode.

We encapsulate all communication with the RTC driver into a class called Rtc. All data exchange with the driver goes through the /dev/rtc special device file. In the Rtc class ...