A - Starting Lights

Sparkles are very useful - they are LEDs, just like the red/green LED from before, but much cleverer!

They have small chips inside them, which allow you to control many LEDs using just one output. If you look really closely you might be able to see them.

They are also three LEDs in one - there is a red, green and blue LED in every sparkle.

We can control these three internal LEDs separately, and mix them together to create any colour!

This is the same way pixels in your computer screen work - have a look at the chart to see all the possible colours we can make.

Build up your robot like the picture.

Plug the sparkle module into P0.

For now, let's test the sparkles by building the simple program in the picture - hopefully they all turn red when you program your robot!

Don't stare at the sparkle board for too long - it's very bright!

Let's go through this program and see how it works.

import neopixel - this loads some extra code that allows us to use the sparkles. You need this in any program you want to use them in!

pixels=neopixel.NeoPixel(pin0,9) - this sets up pixels to refer to a set of sparkles, connected to pin0, with 9 sparkles in total.

pixels[i]=(255,0,0) - with the for loop changing i from 0 to 8, this line sets each sparkle to red. pixels[0] sets the first sparkle, pixels[1] sets the second one and so on.

The three numbers in this line set the amount of red, green and blue respectively - so 255,0,0 sets red at full, and green and blue completely off.

pixels.show() - this updates the sparkles, and you need this line every time you change any of the sparkle colours.

Try changing the amounts of red, green and blue, and see what colours you can make.

Remember, we can also control each sparkle individually if we take out the for loop.

We can use pixels[pixelNumber]=(red,green,blue) to set the colours of individual sparkles - have a look at the sparkle board to see which sparkle is which number.

In programming numbers start from 0, not 1 - so for nine sparkles, the first is 0, the second is 1 and the last is sparkle 8.

Use three lines of code to set three sparkles to a different colour.

Don't forget to put a pixels.show() line at the end, or you won't see anything happen.

It can be difficult to know what to set the red, green and blue to to get a specific colour!

Try this online colour picking tool - you can pick any colour you like, and it will give you the red, green and blue values you need.

Let's make a set of starting lights for a race across the planet surface.

Check out the F1 starting lights in the video - can you put together a program using sparkle and wait blocks to make your own?

The lights should turn red 3 at a time, then all go green at the same time.