# Play Three Tones

In this lesson we will play three consecutive tones. Each tone will have a specific time on and we will put a time between the tones.

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27``` ``````from machine import Pin, PWM from utime import sleep # lower right corner with USB connector on top SPEAKER_PIN = 16 # create a Pulse Width Modulation Object on this pin speaker = PWM(Pin(SPEAKER_PIN)) speaker.duty_u16(1000) speaker.freq(300) # 1 Kilohertz sleep(.5) # wait a 1/4 second speaker.duty_u16(0) sleep(.25) speaker.duty_u16(1000) speaker.freq(800) sleep(.5) speaker.duty_u16(0) sleep(.25) speaker.duty_u16(1000) speaker.freq(400) sleep(.5) # turn off the PWM speaker.duty_u16(0) ``````

## Using Variables

We can also put the time each tone stays on and the space between the tones into variables so it is easier to modify the values in a single place.

 ```1 2 3 4``` ``````# set the time each tone will be on ONTIME = .5 # the time between the tones OFFTIME = .100 ``````

## Three Tones With Variables

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35``` ``````from machine import Pin, PWM from utime import sleep # lower right corner with USB connector on top SPEAKER_PIN = 16 # create a Pulse Width Modulation Object on this pin speaker = PWM(Pin(SPEAKER_PIN)) # the time each tone will be on ON_TIME = .25 # the time between the tones OFF_TIME = .1 # Low tone speaker.duty_u16(1000) speaker.freq(300) sleep(ON_TIME) speaker.duty_u16(0) sleep(OFF_TIME) # High tone speaker.duty_u16(1000) speaker.freq(800) sleep(ON_TIME) speaker.duty_u16(0) sleep(OFF_TIME) # Medium tone speaker.duty_u16(1000) speaker.freq(400) sleep(ON_TIME) # turn off the PWM speaker.duty_u16(0) ``````

## Experiments

1. Change the ON_TIME in the above program. What is the shortest time that you can still hear?
2. Change the order of the Low, High, Medium around. What is the most pleasing to your ears?
3. What order would you suggest for the start of a game and what order would you like for a "Game Over" sound?