Create a **forever** loop that will constantly display the appropriate brightness on the LED display.
```
basic.forever(() => {
})
```
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.
```
basic.forever(() => {
let acceleration = input.acceleration("y")
})
```
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.
```
basic.forever(() => {
let acceleration1 = input.acceleration("y")
acceleration1 = math.abs(acceleration1)
})
```
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.
```
basic.forever(() => {
let acceleration2 = input.acceleration("y")
acceleration2 = math.abs(acceleration2)
acceleration2 = acceleration2 / 4
})
```
Now let's use our acceleration value to set the brightness on the BBC micro:bit.
```
basic.forever(() => {
let acceleration3 = input.acceleration("y")
acceleration3 = math.abs(acceleration3)
acceleration3 = acceleration3 / 4
led.setBrightness(acceleration3)
})
```
Let's show what the brightness of the micro:bit is by turning all the LEDs on!
