Timers

Question 1

1. The millis() function returns the number of milliseconds since the Arduino board began running the current program.
   
   • True / False

Answer 1

True

Question 2

2. The micros() function returns the number of milliseconds since the Arduino board began running the current program.
   
   • True / False

Answer 2

False.
Answer: millis()

Question 3

3. The every() function in the timer library runs the callback function once after a specified duration.
   
   • True / False

Answer 3

False.
Answer: after()

Question 4

4. The update() function in the timer library must be called from the setup() function.
   
   • True / False

Answer 4

False
Answer: Must be called from the loop() function

Question 5

5. The oscillate() function in the timer library toggles the state of a digital output pin every specified period of time.
   
   • True / False

Answer 5

True

Question 6

6. The pulse() function in the timer library toggles the state of a digital output pin just once after a specified duration.
   
   • True / False

Answer 6

True

Question 7

7. The stop() function in the timer library stops timer events currently running.
   
   • True / False

Answer 7

True

Question 8

8. The repeatCount argument in the every() function specifies the number of times the callback function should be repeated.
   
   • True / False

Answer 8

True

Question 9

9. The after() function in the timer library runs the callback function every specified period of time.
   
   • True / False

Answer 9

False
Answer: Once after a specified duration, not repeatedly at a specified period of time

Question 10

10. The millis() function overflows after approximately 70 minutes.
    
    • True / False

Answer 10

False
Answer: Overflows after approximately 50 days

Question 11

1. What does the millis() function return?
   • a) The number of microseconds since the Arduino board began running the current program.
   • b) The number of milliseconds since the Arduino board began running the current program.
   • c) The number of milliseconds since the Arduino board was manufactured.
   • d) The number of microseconds since the Arduino board was manufactured.

Answer 11

b) The number of milliseconds since the Arduino board began running the current program.

Question 12

3. Which function is used to run a callback function every specified period of time?
   • a) every(long period, callback)
   • b) after(long duration, callback)
   • c) oscillate(int pin, long period, int startingValue)
   • d) pulse(int pin, long period, int startingValue)

Answer 12

a) every(long period, callback)

Question 12

2. How long does it take for the millis() function to overflow?
   • a) Approximately 50 minutes
   • b) Approximately 50 hours
   • c) Approximately 50 days
   • d) Approximately 50 weeks

Answer 12

c) Approximately 50 days

Question 13

4. What is the purpose of the pulse() function?
   • a) To toggle the state of a digital output pin every specified period of time.
   • b) To stop a timer event running.
   • c) To update all the events associated with the timer.
   • d) To toggle the state of a digital output pin just once after a specified duration.

Answer 13

d) To toggle the state of a digital output pin just once after a specified duration.

Question 14

5. How do you specify the number of times a callback function should be repeated in the every() function?
   • a) By passing an additional argument for the repeat count.
   • b) By using the repeatCount keyword.
   • c) By calling the repeat() function inside the callback.
   • d) By setting a global variable.

Answer 14

a) By passing an additional argument for the repeat count.

Question 15

6. Which function should be called from the loop function to service all the events associated with the timer?
   • a) every()
   • b) after()
   • c) stop()
   • d) update()

Answer 15

d) update()

Question 16

7. How long does it take for the micros() function to overflow?
   
   • a) Approximately 70 seconds
   • b) Approximately 70 minutes
   • c) Approximately 70 hours
   • d) Approximately 70 days

Answer 16

b) Approximately 70 minutes

Question 17

8. Which function is used to toggle the state of a digital output pin every specified period of time?
   • a) every()
   • b) after()
   • c) oscillate()
   • d) pulse()

Answer 17

c) oscillate()

Question 18

9. What does the oscillate() function do?
   • a) Runs the callback once after a specified duration.
   • b) Toggles the state of a digital output pin every specified period of time.
   • c) Stops a timer event running.
   • d) Updates all the events associated with the timer.

Answer 18

b) Toggles the state of a digital output pin every specified period of time.

Question 19

10. Which library is used for timer functions?
    • a) Timer.h
    • b) TimerLib.h
    • c) Timer.h library
    • d) timer.h

Answer 19

a) Timer.h

Question 20

1. What function returns the number of milliseconds since the Arduino board began running the current program?

Answer 20

millis()

Question 21

2. Name one function from the timer library used to run a callback function every specified period of time.

Answer 21

• every()
• after()
• oscillate()
• pulse()

Question 22

3. What is the purpose of the oscillate() function in the timer library?

Answer 22

Toggles the state of a digital output pin every specified period of time.

Question 23

4. How is the number of times a callback function should be repeated specified in the every() function?

Answer 23

By passing an additional argument for the repeat count.

Question 24

5. What function should be called from the `loop` function to service all the events associated with the timer?

Answer 24

update()

Question 25

6. How long does it take for the `micros()` function to overflow?

Answer 25

Approximately 70 minutes

Question 26

7. Briefly describe the purpose of the `pulse()` function in the timer library.

Answer 26

Toggles the state of a digital output pin just once after a specified duration.

Question 27

8. What is the function of the `stop()` function in the timer library?

Answer 27

Stops a timer event running

Question 28

9. What function is used to toggle the state of a digital output pin just once after a specified duration?

Answer 28

pulse()

Question 29

10. Which Arduino library provides timer functions for managing timed events in a sketch?

Answer 29

Timer.h