Home/Documentation/RTC Interface

This interface extends the Sensor interface and is used to define the functions that all RTC sensors must implement. This specifically includes accurate time readings. The RTC class is responsible for parsing the module's data into local variables. The State class then reads these variables to get the data.

Note: The getDataString() and getStaticDataString() functions are expected to return heap-allocated char*s. This is because the State class is responsible for freeing the memory after the data is used. getCsvHeader() is expected to return a char[] as a string literal (i.e. Don't delete[] it).

Rather than list out all the functions here, I will refer you to the header file for the RTC class. This prevents outdated documentation. The functions are documented in the header file.

Some important ideas to note:

• The RTC interface overrides the getType() and getTypeString() functions itself rather than leaving it to the fully derived implementation. This just makes it a bit easier to use.
• The RTC class has a dependency on Adafruit's imumaths library for vector math and storage. This is used to store time variables as vectors of doubles. The library is included in the project, so you shouldn't need to worry about it.
• The RTC class also has a dependency on the RTClib library for interfacing with the RTC module. As this class is unused, the library may or may not be currently included in the project.

• Sensor.h - The Sensor interface.
• imumaths - The Adafruit library used for vector math and storage.
• State.h - The State estimation system.

A Real-Time Clock (RTC) is a computer clock that keeps track of the current time. It is used to provide accurate time readings to the flight computer. Our current RTC is the DS3231, which is a highly accurate RTC module that can provide time readings accurate to within a few seconds per year. The RTC is used to provide an accurate time reference for the flight computer, which is important for logging data and for time-sensitive operations.

We have decided not to use an RTC at this time because we do not need time data that is so incredibly precise. The Teensy's internal RTC is plenty accurate for the purposes of our flight computer.