> For the complete documentation index, see [llms.txt](https://sharinghub-eng.kittenbot.hk/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sharinghub-eng.kittenbot.hk/functional_module/rgb/ledmatrix/neopixel2.md).

# RGB LED Screen and Matrices

This tutorial is about RGB LED Screen and Matrices, understanding matrices allow us to create more complicated patterns.

### Wiring

RGB LED Screen is used with the Robotbit, please refer to the following figures.

#### 1. Connect the screen to the adapter.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/matrixtoadapter.jpg)

#### 2. Connect the adapter to Robotbit。

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/adaptertorobotbit.png)

#### 3. For prolonged use, connect a USB power.

As power is delivered via USB, you don’t have to use the 5V pin on the adapter.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/usb1.jpg)

#### 4. Demonstration of wiring

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/usbpower.jpg)

### RGB LED Screen and Matrices

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/Matris.png)

A matrix can be understood as a table with X and Y axes. So a table with 10 columns and 10 rows can be understood as a 10x10 matrix.

For example, a resolution of 1920x1080 is a matrix of 1920x108.

In other words, the 8x32 or 16x16 screens are also matrices.

### Makecode Coding tutorial

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/mcbanner2.png)

#### Load the NeoPixel extension.

We can initialize the screen as a 16x16 matrix. Pixels can be selected by using coordinates.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/code82.png)

[Sample Code Download](https://bit.ly/LEDMatrixT3_01Hex)

[Sample Code Link](https://makecode.microbit.org/_WWiYHp7F50Cg)

Lighting up the first pixel in the first 2 rows.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/code43.png)

[Sample Code Download](https://bit.ly/LEDMatrixT3_02Hex)

[Sample Code Link](https://makecode.microbit.org/_T02XMz8ooihy)

We can see that the pixel that lights up is different in the 2 rows despite having the same X value.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/ww.jpg)

This is because the screen is wired in a zig zag pattern, so the direction of X changes on each row(Refer to the following figure).

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/asd.png)

In our code, the direction of X is from right to left on the first row(Y=0).

But on the second row(Y=1), the direction of X is left to right.

Therefore, when Y is and odd number, we have to reverse the position of X.

```
Computers count from 0.
```

Reversing is simple, we just have to minus X from the width of the matrix.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/code52.png)

[Sample Code Download](https://bit.ly/LEDMatrixT3_03Hex)

[Sample Code Link](https://makecode.microbit.org/_bjMWtxVJpffc)

```
Although the matrix width is 16, but computers count from 0. So we have to minus 1.(16-1=15)）
The RGB module from Powerbrick does not need this modification.
```

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/www.jpg)

As a result, we need to modify X when displaying patterns.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/code72.png)

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/triangle.jpg)

[Sample Code Download](https://bit.ly/LEDMatrixT3_04Hex)

[Sample Code Link](https://makecode.microbit.org/_5Fiag7F001ec)

### Matrix Rotation

The following code shows the effect on the X and Y axis when rotating the matrix.

Rotating the matrix may sometimes be helpful.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/code18.png)

```
There are 3 kinds of rotation.
```

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/rotate.gif)

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/rotate32.gif)

[Sample Code Download](https://bit.ly/LEDMatrixT3_05Hex)

[Sample Code Link](https://makecode.microbit.org/_E95HhRdT5gPX)

Refer to this figure for the relation between the axes and rotation.

![](https://kittenbothk-eng.readthedocs.io/en/latest/_images/image8554.png)

### Extension Version and Updates

There may be updates to extensions periodically, please refer to the following link to update/downgrade your extension.

[Makecode Extension Update](https://kittenbothk-eng.readthedocs.io/en/latest/Makecode/makecode_extensionUpdate.html)

### FAQ

Q: Why is red the only colour lit up when I try to use different colours?

A: There is not enough power.

Solution: Reduce brightness or turn on the power on the Robotbit, or connect to a USB power.

### Precautions

* Do not connect a power supply with a voltage higher than 5V.
* Connect to a USB power supply when for prolonged use.
* Lower the brighness when a lot of LEDs are lit.
* This product is suitable for users aged over 14, children aged 8-14 need to be under the supervision of an adult when using this product.
* Please refer to Kittenbot’s official guidelines before using, wiring must follow the guidelines, do not use a high power servo or motor when using this product.
* To avoid short circuiting, do not put this product on conductive surfaces such as metal.
* To avoid short circuiting, do not put this product in water.
* Do not touch the exposed wires with bare hands.