76 lines
2.2 KiB
Markdown
76 lines
2.2 KiB
Markdown
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# glowing pendulum activity
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construct a pendulum that glows using acceleration. #docs
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### ~avatar avatar
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Welcome! This guided activity will teach how to construct a pendulum that glows using acceleration. Let's get started!
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### ~
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To create a new script, go to the [Create Code](/microbit/create-code) page and tap *New Project* under **Touch Develop**.
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Create a **forever** loop that will constantly display the appropriate brightness on the LED display.
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```
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basic.forever(() => {
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})
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```
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Now let's measure the acceleration on the `y` axis and store that value in a variable. The `input->acceleration("y")` function will provide the value.
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```
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basic.forever(() => {
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let acceleration = input.acceleration("y")
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})
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```
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Since the micro:bit will be swinging back and forth, the acceleration will only be positive half of the time. Thus, to always get a positive value, we want to take the absolute value of the acceleration.
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```
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basic.forever(() => {
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let acceleration1 = input.acceleration("y")
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acceleration1 = math.abs(acceleration1)
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})
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```
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The function `input->acceleration("y")` returns a number between 0 and 1024. We want to use this value for the brightness of the micro:bit, but the `led->set brightness()` only accepts a value between 0 and 256. Thus, we need to divide the acceleration by 4 to ensure we will be in the appropriate range.
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```
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basic.forever(() => {
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let acceleration2 = input.acceleration("y")
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acceleration2 = math.abs(acceleration2)
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acceleration2 = acceleration2 / 4
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})
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```
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Now let's use our acceleration value to set the brightness on the BBC micro:bit.
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```
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basic.forever(() => {
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let acceleration3 = input.acceleration("y")
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acceleration3 = math.abs(acceleration3)
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acceleration3 = acceleration3 / 4
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led.setBrightness(acceleration3)
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})
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```
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Let's show what the brightness of the micro:bit is by turning all the LEDs on!
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```
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basic.forever(() => {
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let acceleration4 = input.acceleration("y")
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acceleration4 = math.abs(acceleration4)
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acceleration4 = acceleration4 / 4
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led.setBrightness(acceleration4)
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led.plotAll()
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})
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```
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### ~avatar avatar
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Excellent, you're ready to continue with the [challenges](/microbit/lessons/glowing-pendulum/challenges)!
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### ~
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