Home
✔ 뷰어로 보기
Pi
2016.10.25 11:46

[Arduino] Timer 라이브러리 사용하기

조회 수 14590 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/3768817/6f8/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
311 Android gdb commands 2015.03.11 8114 0
310 Android Android GDB Debugging secret 2015.03.11 0 0
309 Android SQLite database를 csv로 저장하기, 읽어오기 2015.03.04 12078 0
308 Android SQLite 데이타 베이스 다루기 2015.03.03 7648 0
307 Android Android DB 생성 및 관리 ( Cursor , Query ) 2015.03.03 24297 0
306 Android 안드로이드에서 Database를 다뤄보자 2015.03.03 17691 0
305 Android 안드로이드 웨어 디자인 (Android Wear Design) [Korean] 2015.02.25 7278 0
304 Android Android studio vmoptions 메모리 설정 2015.02.22 11619 0
303 업무 Dump 받은 파티션을 mount해서 보는 방법 secret 2015.02.12 0 0
302 일반 네트워크 특정 IP 작업그룹/컴퓨터명 정보 조회 1 2015.02.10 10454 0
301 JAVA JAVA String 클래스 메소드 정리 1 2015.02.05 85715 0
300 LINUX 도우 gvim에서 사용하고 있는 _vimrc 파일 2015.01.26 8757 0
299 LINUX 리눅스의 기본 명령어들 2015.01.20 7175 0
298 LINUX bash 의 명령어 History 2015.01.20 7730 0
297 Android EME(Encrypted Media Extensions) 설명 자료 2015.01.19 11020 0
목록
태그 쓰기
Board Pagination ‹ Prev 1 ... 9 10 11 12 13 14 15 16 17 18 ... 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