Hardware Setup

Hardware

For implementation, you will need four main components:

1. Controllable LED RGB strip,
2. Power supply,
3. Microcomputer Arduino,
4. Android Ambilight Application.

First a small amount of explanation.

WS2811 is a three-channel channel controller / driver (chip) for RGB LEDs with one-wire control (addressing to an arbitrary LED). The WS2812B is an RGB LED in the SMD 5050 case, in which the WS2811 controller is already integrated.

Suitable for the project LED strip for simplicity is called – WS2811 or WS2812B.

WS2812B strip is a LED strip on which the LEDs WS2812B are sequentially placed. The LED strip works with a voltage of 5 V. There are LED stripes with different density of LEDs. Usually it is: 144, 90, 74, 60, 30 for one meter. There are different degrees of protection. Most often it is: IP20-30 (protection from solid particles), IP65 (protection against dust and water jets), IP67 (dust protection and protection for partial or short-term immersion in water to a depth of 1 m). The substrate is black and white.

Here is an example of such a LED strip:

ws2812b

WS2811 strip is a LED strip on which the WS2811 controller and some kind of RGB LED are sequentially located. There are options designed for a voltage of 5 V and 12 V. Density and protection are similar to the previous version.

Here is an example of such a LED strip:

ws2811

Which LED strip should I choose, WS2812B or WS2811?

An important factor is the power of the LED strip, which I’ll talk about a little later.

If you have a power supply that is suitable for power (often at home from old or damaged equipment, power supplies remain), then choose a LED strip based on the power supply voltage, i.e. 5V – WS2812B, 12V – WS2811. In this case, you will simply save money.

From myself I can give a recommendation. If the total number of LEDs in the system is not more than 120, then WS2812B. If more than 120, then WS2811 with a working voltage of 12 V. Why so, you will understand when it comes to connecting the LED strip to the power supply.

What level of LED strip protection should I choose?

For the most suitable IP65, as on one side it is covered with “silicone” (epoxy), and on the other there is a self-adhesive surface of 3M. This LED strip is conveniently mounted on a TV or monitor and can be conveniently wiped from dust.

What density of light-emitting diodes to choose?

For the project, LED stripes with a density of 30 to 60 LEDs per meter (of course, you can and 144, no one forbids). The higher the density, the greater the Ambilight resolution (the number of zones) and the greater the maximum total brightness. But it should be taken into account that the more LEDs in the project, the more complicated the power scheme will be, and a more powerful power supply will be needed. The maximum number of LEDs in the project is 300.

Which power supply to choose for a LED strip?

The power supply is selected for power and voltage. For WS2812B – voltage 5 V. For WS2811 – 5 or 12 V. The maximum power consumption of one WS2812B LED 0.3 watts. For WS2811 in most cases the same. Those. the power supply should not be less than N * 0.3 W, where N is the number of LEDs in the project.

For example, you have a TV 42 “and you stopped on a LED strip WS2812B with 30 LEDs per meter, you need 3 meters of LED strip (all 4 sides of the screen) .You need a power supply with a voltage of 5 V and a maximum power of 5 V / 6 A. If there are less diodes on the lower horizontal of the screen than on the top, it is only about 60 LEDs – power from 5 V / 4 A.

Example of a power supply for a LED strip:

power supply

Which microcontroller to choose?

Managing Ambilight is an Arduino microcomputer. Arduino Nano on Aliexpress costs about $ 2.5 apiece.

Example of microcontroller:

arduino

Project costs for a conventional 42 “TV:

12 $ – 3 meters WS2812B (30 LEDs per meter)
4 $ – power supply 5 V / 4 A
$ 2.5 – Arduino Nano
$ 3 – Android Ambilight Application program


Total:  ~ $ 21.5


Buy the whole set at once, you can from our partner:


Hardware implementation

The most important thing is to properly organize the feed of the LED strip. The LED strip is long, the voltage drops with a large current consumption, especially when using 5 V tape. Most of the problems that arise in those who make themselves Ambilight, are associated specifically with nutrition. I use the rule – you need to make a separate power supply for every 10 W of maximum power consumed at 5 V and 25 W of power consumption at 12 V. The length of the power supply (from the power supply to the LED strip itself) should be minimal (without reserve), especially at 5 AT.

The general connection scheme is as follows (Arduino is powered from USB, and the LED strip from the PSU):

connection scheme

To the LED strip from both ends power is supplied – two parallel connections. For example, if we made the backlight on all 4 sides, and the LED strip would have 60 LEDs per meter (that is, the maximum power 54W), then we would make such a power supply:

power connection

To Arduino from the LED strip there are two contacts. 1 – GND, which must be connected to the corresponding contact on Arduino. And 2 – DATA, which must be connected to the sixth digital contact on Arduino through a 470 Ohm resistor. If you do not have a resistor, in most cases everything will work fine without it, but it is better that it should be. The resistor can be bought for a couple of cents in any radio store. The Arduino microcomputer itself can be placed in any convenient housing, many use for this purpose a container from “Kinder Surprise”. Arduino should be placed as close as possible to the LED strip, so that the connection from DATA to Arduino has a minimum length.

Soldering the wires to the LED strip is easy. The main rule – the time of contact with the soldering iron should be minimal!

How to bend the tape at right angles?

There are two options. 1 – the LED strip should be cut and connected with short wires (placing it all in a shrink tube). 2 – You can buy special angled connectors for three contacts for LED stripes:

angled connectors

The software part

This is the simplest.

Download and install Arduino IDE. We load the last available version of the FastLED library, unpack it and put the FastLED folder from the archive into the folder with the Arduino IDE libraries (C:Program Files (x86)Arduinolibraries). Start Arduino IDE and close it. The folder Arduino will be created in the Documents folder. In it we create a folder AAA and copy there sketch – AAA.ino.

Connect the Arduino microcomputer to USB. The driver (serial interface CH340) will be installed automatically. If this does not happen, then in the folder Arduino IDE there is a folder Drivers with everything you need.

Run Arduino IDE and open the file AAA.ino.

aaa-1en

We change (if necessary) the data transfer rate:

aaa-2en

We change the number of LEDs. The number should be equal to the number of LEDs in your LED strip:

aaa-4en

Tools> Board> Arduino nano
Tools> Port> Select the COM port (there will be the desired option)

Press the button “Upload”:

aaa-3en

The program will inform you when the download is complete (this is literally a couple of seconds).

Done. It is necessary to disconnect Arduino from USB and reconnect. The LED strip will turn on in succession in red, green and blue – Arduino is activated and ready to go.

Now you can connect the Arduino to the TV-box and start setting up the program.