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Simpler language; added another (simpler) example.

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Ron Hale-Evans 2016-05-23 13:41:01 -07:00
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docs/reference/input/light-level.md
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# Light Level # Light Level
Gets the light level from ``0`` (dark) to ``255`` (bright). The light is measured by using various LEDs from the screen. Find the light level where you are.
The light level ``0`` means darkness and ``255`` means bright light.
The BBC micro:bit measures the light around it by using some of the
LEDs on the [LED screen](/device/screen).
This function will return ``0`` on the first call to this method, a light reading will be available after the display has activated the light sensor for the first time. The first time you use it, this function will say ``0``.
After that, it will say the real light level.
This is because the light sensor (the part that can find the light level)
has to be turned on first.
```sig ```sig
input.lightLevel(); input.lightLevel();
@ -10,11 +16,26 @@ input.lightLevel();
### Returns ### Returns
* [Number](/reference/types/number) - light level from ``0`` (dark) to ``255`` (bright). * a [Number](/reference/types/number) that means a light level from ``0`` (dark) to ``255`` (bright).
### Example: show light level
When you press button `B` on the microbit, this
program shows the light level
on the [LED screen](/device/screen).
```blocks
input.onButtonPressed(Button.B, () => {
let level = input.lightLevel()
basic.showNumber(level)
})
```
### Example: chart light level ### Example: chart light level
Use `plot bar chart` to visual the influence of various light source on the light level. This program shows the light level with a [bar chart](/reference/led/plot-bar-graph) on the micro:bit screen.
If you carry the micro:bit around to different places with different light levels,
the bar chart will change.
```blocks ```blocks
basic.forever(() => { basic.forever(() => {