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docs/reference/js/lessons/night-light/challenges.md

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+# night light challenges
+
+Coding challenges for the night light tutorial. #docs
+
+## Before we get started
+
+Complete the following guided tutorial:
+
+* [tutorial](/microbit/lessons/night-light/tutorial)
+
+At the end of the tutorial, click `keep editing`. Your code should look like this:
+
+```
+led.setBrightness(255)
+led.plotAll()
+input.onButtonPressed("A", () => {
+    led.setBrightness(64)
+})
+```
+
+### Challenge 1
+
+### @video td/videos/night-light-2
+
+What if we want to turn off all the LEDs? Let's do this by setting the brightness to `0` when button `B` is pressed. Add an event handler with `input->on button pressed(B)` add `led->set brightness(0)` to turn off the LEDs.
+
+```
+led.setBrightness(255)
+led.plotAll()
+input.onButtonPressed("A", () => {
+    led.setBrightness(64)
+})
+input.onButtonPressed("B", () => {
+    led.setBrightness(0) // ***
+}) // ***
+```
+
+**Challenge 3**
+
+Add an event handler with `input->on screen up` to change the LED brightness back to a `255`.
+
+* `Run main` your script to see the LEDs change brightness.