The time that has elapsed since an instant. Instant: A specific instant in time (“time-point”) read from a clock.ĭuration: The difference of two instants. Timer: An entity that counts toward an expiration. Wrapping Clock: A clock that when at its maximum value, the next count is the minimum In this context as long as it fulfills the other requirements. DefinitionsĬlock: Any entity that periodically counts (ie an external or peripheral hardware In addition, a wide range of rate-type types are available including Hertz,īitsPerSecond, KibibytesPerSecond, Baud, etc.Ī Duration type can be converted to a Rate type and vica-versa. Part directly which in this case is the number of milliseconds represented by the Duration.Ĭonversion arithmetic is only performed when explicitly converting between time units (eg. Milliseconds, a call to the Duration::integer() method simply returns the integer Structure is that it avoids unnecessary arithmetic. Durations and Rates areįixed-point values as in they are comprised of integer and scaling factor values. The approach taken is similar to the C++ chrono library. Requesting theĭifference between two Instants gives a Duration which can have different precision and/or The Clock has the same precision and width (inner type) as the Clock. Time-keeping entity from which you read the current instant in time, or is it that instant inĪs an alternative, the current instant in time is read from a Clock. This way is a violation of the separation of concerns principle. 4.45K subscribers Subscribe 3.8K views 2 years ago Arduino Nextion Real-Time Clock In this video, I go over the Arduino using the Millis () command as a Real-Time Clock. There is generally no concept of a “Clock”. In the Rust ecosystem, it appears to be idiomatic to call a now() associated function from an It also adds a lot of functionally that would seldom be useful in an embedded context.įor instance it has a comprehensive date/time formatting, timezone, and calendar support. It suffers from some of the same drawbacksĪs the core::Duration type (namely the storage format) and the Instant struct dependency on Support a subset of features in no_std contexts). The time crate is a remarkable library but isn’t geared for embedded systems (although it does This is much slower than this project’s implementation of what is analogous to a tagged union.Any read (with the exception of seconds and nanoseconds) requires arithmetic to convert to the.This is huge overkill and adds needless complexity beyond what is required (or desired) for.The storage is u64 seconds and u32 nanoseconds.Drawbacks of the standard library types Duration Embedded systems generallyĭon’t know (nor do they care) what the real time is, but rather how much time has passed since Instance, on an OS, the time is measured against an arbitrary epoch. The handling of time on embedded systems is generally much different than that of OSs. to_rate() // 5 Hz assert_eq!( frequency, Ok( 5_u32.

into() // 200 ms let frequency: Result = millis. microseconds() // 200_000 μs let millis: Milliseconds = micros.

Real time clock with milliseconds