Sunday, March 6, 2016

130" Screen DIY for Beam Projector Build Log #02 : Ambilight + wire mounting

Hello all my friends.
The first build log is not that much interesting... i guess.
I hope the first build log would help someone to build his own fixed screen.
Anyway, let's start the second build log!

As the log is quite lengthy, I wanna show you the final shots first.
Then, the log will come later.

This shows how the screen is mounted on the wall.
I used wires and anchor.
Leveling with laser was hard stuff.

This shows the LED light from the backside of screen.
Without screen, it is still beautiful.

The LED light plays a role of ambilight.
LED lines actively react with the edge color of the screen.

Red and blue... nice example.

Test with different picture.

More pic

This is the extreme case showing the charm of the ambilight.

Obviously, the LED lines change their colors during a movie play.
This shows the example by the hobbit.

Ok, let's start!
The screen was deformed little bit, though I wrote down it is not in the previous build log.
I rechecked the dimensions, and found it is deformed.
So, I ordered new aluminium profiles to cure the issue.
The new profiles are newly inserted (red circles).

From different view..
Luckly, there is no more deformation issue.

It's time to attach ambilight technology.
The first ambilight tech. was invented by Philips, then many people mimic it by Arduino, Teensy or Raspberry Pi.
Usually, they apply this tech to a small size of monitor.
Nobody tried ambilight on this kind of huge screen.

Anyway, there are bunch of literatures about ambilight in the internet.
My combination is "Teensy 3.2 + OctoWS2811 board + WS2812B LED lines".
Many people try with Arduino, but Teensy 3.2 is best choice if you consider the response speed.
There are many ways to choose LED lines, and many peple use WS2812B.
Therefore, if you choose WS2812B, many people can help you when you are stuck with troubles.
I bought WS2812B with 30LEDs/meter considering power and response rate.
And.. do not worry about a code.
You just need to upload "Adalight" example source code on Teensy, and setting with Ambibox software. Done! Easy!

The best instruction I have found is the following youtube link.
He explains in details, so you can follow him easily.

Ok, the first step is taping the screen size on the floor.

Then, align LED lines following the taping.
In my case, I need 50 LEDs in the horizontal line, and 30 LEDs in the vertical line.
260 LEDs are needed.

Looking at the LED, there are 5v, GND, and data line.
Don't worry about wiring, you can learn about wiring of LEDs refering to the following link.

Prepare some stuffs for wiring.

Haha, I didn't have proper tools, so just connect the raw electric wire without ring terminal.
This power supply will feed 5v DC power to LED lines converting 220v AC power.
100 watt power is more than enough to feed 260 LEDs.

Next, Teensy 3.2 was soldered onto OctoWS2811.
In short, OctoWS2811 communicate with LED by LAN cable (cat.6) via data line on LED.
As my English sucks, you'd better to refer to the following link.
You can learn basics about OctoWS2811 in the website.

As all stuffs are prepared, it's time to attach LEDs on the backside of the screen.

I bought LEDs from aliexpress, and doble-sided tape was already attached on it.
So this work was easy part.

Quickly done!

To consider response time, you should divide long LED lines into several parts.
In my case, I decided to seperate LED lines into 4 lines.
So each line has 260/4=65 LEDs.
Therefore, I must feed LED power to each LED lines. (also data line by LAN cable)

My strategy is shown in the followin pic.
"앞" means.."front" (Korean)
Anyay, power supply feeds four LED lines, and the data lines will be started in the order of the folloing picture.
By this strategy, I can align wires neatly.
BUT the ambibox setting will be terrible as the data feeding order has no rule.....(it took me around more than 2 hours.)

Every corner point has discontinous lines of LEDs.
So i need to solder LEDs on every corner point.

Carefully, I soldered them..
Use paste when soldering, then the soldering will be much easier.

Other coner points..

Finally done!

One LAN cable was cut for data communication between Teensy and LEDs.

For easy connection, the following female (or male) connector was wired.
So this connector can be directly connected to LED.
Very kindly, aliexpress seller provides pre-soldered data connectors on LED lines with seperated power lines.

To prevent voltage drop, I used very thick electric wire for feeding power to LEDs.
In the following pic, the red color is connected to 5v, and the white line is connected to GND of the power supply.

Power wiring is done.

Luckly, the wire can be slotted in the side hole of aluminium profiles.
Very neat!

Shows wiring on the power supply side.

From different view..
The power supply was positioned by T-nut & bolt.

After then the data line connection was done.

Using the prepared female & male connectors, the data lines are easily connected.

After all wiring is done, the Adalight example code is little bit modified to test it.
It runs well w/o any problems.
At first time, the second LED lines were DEAD.
My mentality was almost collapsed, but found that the LAN cable was melt by heatgun.
So, the two lines wer short.
Luckly the problem was easily solved by removing the molten part.

After the test, the wiring was rearranged in a neat form.

Teensy board was attached by double sided tape.

Intersect point...

Shows the power and data line connection.

Lean on the wall.
Messy back side is hidden.

Before mounting the screen, ambilight was tested with Diablo 3.

So the screen was not aligned properly.
Anyway, it works well!!

Now, it is time to mount the screen on the wall.
I chose to use rail wire. (Do not know the proper word in English)

First, I need to insert this kind of part on my wall (it is not concrete)

Like this.

But, some part is concrete....!#$@#$JIQ#$JIQW#RJFUC!@#K
Use this kind of tool (anchor?)

Attach two rails.

In this rail, the anchor with wire will be hanged.

This kind of hook & anchor & wire system.

Hanging the screen.... I was almost dead.

Anyway, I succeed!

One power line and one usb line are getting out from the down side.

If no projector shot, it is still beatiful for the interior design.

At night, it is more gorgeous.

Test with several pics.

Extreme case with colorfule pic.

The projector is positioned on the following stuff.
That is my 2nd DIY beam projector with 1920x1200 resolution.

Time to show off.
As the movie ratio is 16:9, I manually streched the movies to 16:10 ratio to fit my projector.


The Hobbit


Hope you enjoyed my build log.
See you!


  1. Hi,
    can you post the link to buy the materials?

    1. Except Teensy, you can find all stuffs in