noTone() to stop sound in Arduino - Step-by-Step Execution

Concept Flow - noTone() to stop sound

Start

↓

Call tone(pin, freq)

↓

Sound plays on pin

↓

Call noTone(pin)

↓

Sound stops on pin

↓

End

The program starts, plays a tone on a pin, then stops the sound by calling noTone on the same pin.

Execution Sample

Arduino

tone(8, 1000);  // Play 1000Hz tone on pin 8
delay(1000);      // Wait 1 second
noTone(8);        // Stop sound on pin 8

This code plays a 1000Hz sound on pin 8 for 1 second, then stops the sound.

Execution Table

Step	Action	Pin	Frequency	Sound State	Output
1	Call tone()	8	1000	Playing	Tone starts on pin 8 at 1000Hz
2	delay(1000)	-	-	Playing	Sound continues for 1 second
3	Call noTone()	8	-	Stopped	Sound stops on pin 8
4	End	-	-	Stopped	No sound playing

💡 Sound stops after noTone() is called on pin 8

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
pin 8 sound state	Stopped	Playing	Playing	Stopped	Stopped

Key Moments - 2 Insights

Why does the sound stop after calling noTone(8)?

Because noTone(8) tells the Arduino to stop generating the sound on pin 8, as shown in step 3 of the execution_table.

What happens if noTone() is not called after tone()?

The sound will keep playing indefinitely on the pin, as seen between steps 1 and 2 where the sound state remains 'Playing'.

Visual Quiz - 3 Questions

Look at the execution_table, what is the sound state on pin 8 after step 2?

A Playing

B Stopped

C Paused

D Undefined

💡 Hint

Check the 'Sound State' column for step 2 in the execution_table.

At which step does the sound stop playing on pin 8?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look for when 'Sound State' changes to 'Stopped' in the execution_table.

If we remove noTone(8), what would happen to the sound state after step 3?

A It would become Stopped

B It would remain Playing

C It would pause

D It would cause an error

💡 Hint

Refer to key_moments about what happens if noTone() is not called.

Concept Snapshot

tone(pin, frequency) starts sound on a pin
noTone(pin) stops sound on that pin
Use noTone() to end a tone early
Without noTone(), sound plays indefinitely
Works on Arduino digital pins

Full Transcript

This example shows how to use noTone() to stop a sound started by tone() on an Arduino pin. First, tone(8, 1000) starts a 1000Hz sound on pin 8. The program waits 1 second with delay(1000), during which the sound plays. Then noTone(8) is called to stop the sound on pin 8. The execution table tracks each step: starting the tone, waiting, stopping the tone, and ending. The variable tracker shows the sound state on pin 8 changing from stopped to playing, then back to stopped. Key moments clarify that noTone() is necessary to stop the sound, otherwise it plays forever. The quiz tests understanding of when the sound stops and what happens if noTone() is omitted. The snapshot summarizes the key points: tone() starts sound, noTone() stops it, and noTone() is needed to end the sound early.