Home
✔ 뷰어로 보기
Pi
2016.10.25 11:46

[Arduino] Timer 라이브러리 사용하기

조회 수 14217 댓글 0
?

단축키

Prev이전 문서

Next다음 문서

가 + - Up Down Comment Print
?

단축키

Prev이전 문서

Next다음 문서

가 + - Up Down Comment Print

http://playground.arduino.cc/Code/Timer


Navigation

Information

Description

Similar to SimpleTimer, which I discovered after writing this library, this library also allows control of pins in a similar way to Metro, so I guess its a bit like a fusion of the two.

The library does not interfere with the built-in timers, it just uses 'millis()' in a crude type of scheduler to decide when something needs doing.

Examples

The Arduino 'delay' function is both a blessing and a curse. Its great for showing beginners how to make an LED flash. But as soon as you get more complex and start slowing down your 'loop' function you will run into problems.

A classic example is turning a relay on for 10 minutes. The 'delay'-way looks like this:

  1. int pin = 13;
  2.  
  3.  
  4. void setup()
  5. {
  6.   pinMode(13, OUTPUT);
  7.   digitalWrite(pin, HIGH);
  8.   delay(10 * 60 * 1000);
  9.   digitalWrite(pin, LOW);
  10. }
  11.  
  12.  
  13. void loop()
  14. {
  15. }
[Get Code]

The disadvantage of the delay approach is that nothing else can go on while the 'delay' is happening. You cannot update a display, or check for key presses for example.

My 'Timer' library version looks like this:

  1. #include "Timer.h"
  2.  
  3.  
  4. Timer t;
  5. int pin = 13;
  6.  
  7.  
  8. void setup()
  9. {
  10.   pinMode(pin, OUTPUT);
  11.   t.pulse(pin, 10 * 60 * 1000, HIGH); // 10 minutes  
  12. }
  13.  
  14.  
  15. void loop()
  16. {
  17.   t.update();
  18. }
[Get Code]

The 'pulse' method takes arguments of a pin to change, the period to change it for and its initial state.

The call to t.update() will take a matter of microseconds to run, unless the appropriate period of time has passed.

Lets look at another example that uses two timer events. One to flash an LED and another that reads A0 and displays the result in the Serial Monitor.

  1. #include "Timer.h"
  2.  
  3.  
  4. Timer t;
  5. int pin = 13;
  6.  
  7.  
  8. void setup()
  9. {
  10.   Serial.begin(9600);
  11.   pinMode(pin, OUTPUT);
  12.   t.oscillate(pin, 100, LOW);
  13.   t.every(1000, takeReading);
  14. }
  15.  
  16.  
  17. void loop()
  18. {
  19.   t.update();
  20. }
  21.  
  22.  
  23. void takeReading()
  24. {
  25.   Serial.println(analogRead(0));
  26. }
[Get Code]

The first thing to notice is that we are using a callback function called 'takeReading'. We connect it to the Timer using the 'every' command, which in this case, will call the function every second.

We have also attached another event to the timer using the method 'oscillate'. This will cause the LED to toggle state every 100 milliseconds.

Each of the events has an integer ID associated with it, so that you can stop an event, as we do in this example below, which will write to the serial monitor every 2 seconds, flash the LED and after 5 seconds, stop the LED flashing fast, and flash it 5 times slowly.

  1. #include "Timer.h"
  2.  
  3.  
  4. Timer t;
  5.  
  6.  
  7. int ledEvent;
  8.  
  9.  
  10. void setup()
  11. {
  12.   Serial.begin(9600);
  13.   int tickEvent = t.every(2000, doSomething);
  14.   Serial.print("2 second tick started id=");
  15.   Serial.println(tickEvent);
  16.  
  17.   pinMode(13, OUTPUT);
  18.   ledEvent = t.oscillate(13, 50, HIGH);
  19.   Serial.print("LED event started id=");
  20.   Serial.println(ledEvent);
  21.  
  22.   int afterEvent = t.after(10000, doAfter);
  23.   Serial.print("After event started id=");
  24.   Serial.println(afterEvent);
  25.  
  26. }
  27.  
  28.  
  29. void loop()
  30. {
  31.   t.update();
  32. }
  33.  
  34.  
  35. void doSomething()
  36. {
  37.   Serial.print("2 second tick: millis()=");
  38.   Serial.println(millis());
  39. }
  40.  
  41.  
  42. void doAfter()
  43. {
  44.   Serial.println("stop the led event");
  45.   t.stop(ledEvent);
  46.   t.oscillate(13, 500, HIGH, 5);
  47. }
[Get Code]

You can attach up to 10 events to a timer.

Installation

You can download the library from here:

https://github.com/JChristensen/Timer

As with all libraries, unzip the file into the 'libraries' folder in your Arduino directory, which will be in something like 'My Documents\Arduino' on Windows, 'Documents/Arduino' on Mac etc. If this is the first library you have installed, you will need to create a directory there called 'libraries'.

The library is compatible with both Arduino 1.0 and earlier versions.

Usage

int every(long period, callback)

 Run the 'callback' every 'period' milliseconds.
 Returns the ID of the timer event.

int every(long period, callback, int repeatCount)

 Run the 'callback' every 'period' milliseconds for a total of 'repeatCount' times.
 Returns the ID of the timer event.

int after(long duration, callback)

 Run the 'callback' once after 'period' milliseconds.
 Returns the ID of the timer event.

int oscillate(int pin, long period, int startingValue)

 Toggle the state of the digital output 'pin' every 'period' milliseconds. The pin's starting value is specified in 'startingValue', which should be HIGH or LOW.
 Returns the ID of the timer event.

int oscillate(int pin, long period, int startingValue, int repeatCount)

 Toggle the state of the digital output 'pin' every 'period' milliseconds 'repeatCount' times. The pin's starting value is specified in 'startingValue', which should be HIGH or LOW.
 Returns the ID of the timer event.

int pulse(int pin, long period, int startingValue)

 Toggle the state of the digital output 'pin' just once after 'period' milliseconds. The pin's starting value is specified in 'startingValue', which should be HIGH or LOW.
 Returns the ID of the timer event.

int stop(int id)

 Stop the timer event running.
 Returns the ID of the timer event.

int update()

 Must be called from 'loop'. This will service all the events associated with the timer.

Links

See also my blog entry on using this library: http://srmonk.blogspot.com/2012/01/arduino-timer-library.html

Trackback http://www.dreamy.pe.kr/zbxe/3768817/269/trackback
목록
Up위로 Down아래로 Print인쇄
●? 에디터 선택하기
?

Dreamy의 코드 스크랩

내가 모으고 내가 보는

List of Articles
번호 분류 제목 날짜 조회 수 추천 수
416 Pi SSD1306 OLED Displays with Raspberry Pi 2017.05.10 6849 0
415 LINUX 우분투(Ubuntu) 설치된 패키지 목록 확인하기 2016.03.17 6920 0
414 Android 안드로이드 웨어 디자인 (Android Wear Design) [Korean] 2015.02.25 6921 0
413 Pi SD Memory 카드 SPI 3.3V/5.0V 인터페이스 모듈 Atmega2560 제어 예제 2016.12.27 7014 0
412 Pi 무선랜 wifi 설정 2015.10.01 7018 0
411 Pi 아두이노 (Arduino) 소개 및 유형별 종류, 제품별 특징 2016.11.15 7151 0
410 Python 줄 바꿈 없이 출력하는 방법 2019.03.30 7177 0
409 LINUX Ubuntu TFTP 서버 2019.10.30 7194 0
408 Android 안드로이드 소스에서 shell 명령어 실행하기 2014.12.30 7240 0
407 Pi Arduino Pro Mini PIN 정보 file 2018.03.18 7244 0
406 Pi ftp 설정하기 2015.10.01 7261 0
405 일반 [HTML] 복사해서 사용가능한 5개의 실용적인 List Style 예제 2015.11.03 7265 0
404 Android SQLite 데이타 베이스 다루기 2015.03.03 7394 0
403 Android 실시간으로 폰의 pcap 보기 2016.01.05 7398 0
402 Android git archive 를 사용해서 폴더를 .git 제외하고 tar 나 zip 으로 묶기 1 2019.02.10 7435 0
목록
태그 쓰기
Board Pagination ‹ Prev 1 2 3 4 5 6 7 8 9 10 11 ... 34 Next ›
/ 34

나눔글꼴 설치 안내


이 PC에는 나눔글꼴이 설치되어 있지 않습니다.

이 사이트를 나눔글꼴로 보기 위해서는
나눔글꼴을 설치해야 합니다.

✔ 설치 취소

Designed by sketchbooks.co.kr / sketchbook5 board skin

Sketchbook5, 스케치북5

Sketchbook5, 스케치북5

Sketchbook5, 스케치북5

Sketchbook5, 스케치북5