5f7a8e5301
* update yotta defaults for 16kb devices * refactor deprecated blocks * updates for button events * update button events * update refference * update docs * update docs * update button event blocks * update docs * update block id
54 lines
1.4 KiB
Markdown
54 lines
1.4 KiB
Markdown
# Light Level
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Find the light level (how bright or dark it is) where you are.
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The light level ``0`` means darkness and ``255`` means bright light.
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The @boardname@ measures the light around it by using some of the
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LEDs on the [LED screen](/device/screen).
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The first time you use it, this function will say ``0``.
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After that, it will say the real light level.
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This is because the light sensor (the part that can find the light level)
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has to be turned on first.
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```sig
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input.lightLevel();
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```
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Learn more about how light level is detected in this light sensor video:
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https://www.youtube.com/watch?v=TKhCr-dQMBY.
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## Returns
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* a [Number](/types/number) that means a light level from ``0`` (dark) to ``255`` (bright).
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## Example: show light level
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When you press button `B` on the microbit, this
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program shows the light level
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on the [LED screen](/device/screen).
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```blocks
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input.onButtonEvent(Button.B, input.buttonEventClick(), () => {
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let level = input.lightLevel()
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basic.showNumber(level)
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})
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```
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## Example: chart light level
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This program shows the light level with a [bar chart](/reference/led/plot-bar-graph) on the @boardname@ screen.
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If you carry the @boardname@ around to different places with different light levels,
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the bar chart will change.
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```blocks
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basic.forever(() => {
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led.plotBarGraph(input.lightLevel(), 255)
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})
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```
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## See also
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[acceleration](/reference/input/acceleration), [compass-heading](/reference/input/compass-heading)
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