mcu-uuid-common

Description

Microcontroller common utilities library

Purpose

The primary purpose of this library is to maintain a common 64-bit uptime in milliseconds with overflow handling, as long as the loop function is called regularly. Thread-safe on the ESP32 but cannot be used from an interrupt context.

Contents

Usage

#include <uuid/common.h>

Call uuid::loop() regularly and then call uuid::get_uptime_ms() when the uptime is required.

Example

#include <Arduino.h>
#include <uuid/common.h>

class Uptime: public Printable {
public:
	Uptime(uint64_t timestamp_ms = uuid::get_uptime_ms())
			: timestamp_ms_(timestamp_ms) {

	}

	size_t printTo(Print &print) const override {
		unsigned long days;
		unsigned int hours, minutes, seconds, milliseconds;
		uint64_t timestamp_ms = timestamp_ms_;

		days = timestamp_ms / 86400000UL;
		timestamp_ms %= 86400000UL;

		hours = timestamp_ms / 3600000UL;
		timestamp_ms %= 3600000UL;

		minutes = timestamp_ms / 60000UL;
		timestamp_ms %= 60000UL;

		seconds = timestamp_ms / 1000UL;
		timestamp_ms %= 1000UL;

		milliseconds = timestamp_ms;

		size_t len = print.print(F("Uptime: "));
		len += print.print(days);
		len += print.print('+');

		char time[2 + 1 /* hours */
				  + 2 + 1 /* minutes */
				  + 2 + 1 /* seconds */
				  + 3 /* milliseconds */
				  + 1] = { 0 };
		int ret = snprintf_P(time, sizeof(time), PSTR("%02u:%02u:%02u.%03u"),
				hours, minutes, seconds, milliseconds);
		if (ret > 0) {
			len += print.print(time);
		}
		return len;
	}

private:
	uint64_t timestamp_ms_;
};

void setup() {
	Serial.begin(115200);
}

void loop() {
	uuid::loop();

	Serial.println(Uptime());

	delay(1000);
}

Output

Uptime: 0+00:00:00.000
Uptime: 0+00:00:01.000
Uptime: 0+00:00:02.000
Uptime: 0+00:00:03.000
Uptime: 0+00:00:04.000
Uptime: 0+00:00:05.000
Uptime: 0+00:00:06.000
Uptime: 0+00:00:07.000
Uptime: 0+00:00:08.000
Uptime: 0+00:00:09.000
Uptime: 0+00:00:10.000

Resources

Change log

Unreleased

1.2.0 – 2022-10-24

Be thread-safe where possible.

Changed

• Use a mutex where possible to provide thread-safety on non-ESP32 platforms.

1.1.2 – 2022-10-23

Provide thread-safe status.

Added

• Indicate whether this version of the library is thread-safe or not (UUID_COMMON_THREAD_SAFE and uuid::thread_safe).

1.1.1 – 2022-08-03

Use native 64-bit uptime on the ESP32.

Changed

• Use ESP32 function to get the uptime as a 64-bit value.

1.1.0 – 2019-09-15

Printable to string functions.

Added

• Functions to output a Printable to a std::string.

Changed

• Put each function in a separate file to improve linker behaviour.

1.0.2 – 2019-08-16

Fix example.

Fixed

• Example now prints the time part of the uptime instead of ignoring it.

1.0.1 – 2019-08-15

Update example and add tests.

Added

• Test builds of the example.

• Unit tests of the uptime overflow handling.

Changed

• Exclude the test directory from exports of the library source code.

Fixed

• Remove use of Serial.printf() from the example (which does not exist in the standard Arduino library).

1.0.0 – 2019-08-11

First stable release.

Added

• Function void uuid::loop() that should be called regularly.

• Function uint64_t uuid::get_uptime_ms() to get the current uptime as a 64-bit milliseconds value.

• Function std::string uuid::read_flash_string(const __FlashStringHelper *flash_str) to convert flash strings to std::string.

• Type uuid::flash_string_vector for a std::vector of flash strings.