DIY 130 Inch Edgeless Screen With Ambilight by Teensy 3.2+WS2801

by bumhee34

50K54426

Intro: DIY 130 Inch Edgeless Screen With Ambilight by Teensy 3.2+WS2801

Many people have made "ambilight" with Arduino, Teensy, Raspberry Pi, and so on.

I have never seen someone who applied ambilight to a big screen like 130 inch.

Moving to new house, I made 130 inch edgeless (bezeless) screen with ambilight function.

This work could be done thanks to many people who share their knowledge.

I hope this may be helpful to someone who wanna make their own screens or ambilight.

The original post is in my blog : http://bumhee34.blogspot.kr/2016/03/130-screen-diy-for-beam-projector-build.html

STEP 1: What to Prepare?

Screen

  • Screen material : I chose "blackout cloth" from Carl's place. This material needs tension to be streched out.
  • Screen frame : aluminium profile. I ordered 3030 profiles from local store. You need 90 degree joint parts for corners.
  • PU tube : This will be used to fix screen to the frame. I will show you how to do this in few steps. This idea is from https://youtu.be/AxbLfiwBAiw.

Ambilight

  • WS2812B LED strips : this is addressable RGB led to emulate ambilight. I bought it from aliexpress.
  • Teensy 3.2 and Octo2811 board : This can control LEDs. Many use Arduino to run ambilight, but if you should drive many LEDs, Teensy 3.2 is best in terms of performance.
  • Power supply (5v output) : choose a proper power supply. Depends on the total length of the LED strips. In my case, I should drive 260 LEDs, and 100 watt is more than enough to drive them. WS2812B LED consumed around 0.3 watt per LED.

STEP 2: Make Skeleton Frame

Using the joint parts (let me know the English terminology) and "T"-shaped nuts & bolts, you can easily build up the skeleton frame.

No painful work at all.

You may make it with woods and stapler, but wood usually changes its size depending on humidity and heavier than profiles.

I recommend to use aluminium profile.

STEP 3: Stretch and Fix the Screen Using PU Tube

Lay the screen over the frame.

Following the steps from Car's place, "insert" the part of PU tube onto the side hole of aluminium profiles.

In my 3030 profiles, PU tube of outer diameter 10 mm fits to the hole.

This is painful step as PU tube is very rigid.

Use pliers to make the PU part flat, and insert it into the hole.

Then, the tube will fit to the hole and hold the screen tight.

Don't forget to stretch out the screen material all the time.

After this painful time, you will get a gorgeouse flat screen, though I made a big mistake on the corner :(

STEP 4: Test and Having a Rest

This part is not necessary, but I believe many people will be tired at this moment.

So lean the screen on the wall, test and check.

I found noticeble deformation of the frame at this step.

I need to cure the deformation.

Can you see the curve? I had no intension to make a curved screen.

So on the back side, I added two more frames to flatten the screen, and luckly it solved the issue.

STEP 5: Draw the LED Layout, and Attach It!

On the back side of screen, LED strips will be attached.

Depending on your screen size, the number of LEDs are different.

In my case, I need 260 LEDs. After layout work, you can simply attach the LEDs as there is double-sided tape on the LEDs. (It may be different from sellers)

To consider voltage drop and data signal transfer rate, I decided to divide LEDs into four groups.

So, one group has 65 LEDs (260/4). If many LEDs are in one group, you may see delayed reaction of ambilight or flickering.

If you use OctoWS2811, you can divide upto 8 groups. Less LEDs in one group is better, though the wiring will be painful.

To simplify wiring, data lines and power lines are fed into 1 & 3 groups and 2 & 4 groups respectively.

Be careful, ambibox doesnot provide any setting for a "not ordered" LEDs. (I found during test.. too late!)

It only provides scheme for clockwise, or counter clockwise LED lines.

Anyway, the wiring part is user-dependent.

STEP 6: Wiring

The LED data line (and GND) are connected to OctoWS2811 via LAN cable (cat. 6).

LAN cable has 4 groups of lines, and each line consists of two twisted lines.

Each group has colored line and white line, the colored line is connected to "data in" of LEDs, and the white line is coneected to "GND".

You can refer to the pjrc website for wiring.

In my case, I will drive four groups of LEDs, so I only need one LAN cable.

If you drive more than four groups of LEDs, than you need two LAN cables.

OctoWS2811 has two ports, so total 8 groups of LEDs can be controlled by Teensy 3.2 board.

Basically, you can emulate same thing without OctoWS2811, but it will be very painful work.

Using female (or male) connector, you can connect LEDs and LAN cables easily. (My LED has male connectors at the both end sides of the LED strip).

Next, you need to feed 5v power to LEDs.

Once AC electric lines are connected to power supply, DC 5v line is connected to 5v of LED, and GND line is connected to GND of LED. ( AND do not underestimate the wire sizes needed to deliver power to your LEDs.)

Though the data line has starting and end points, power line has no such a rule (parallel not serial).

So, you can connect the power lines at the starting point of LEDs or the end point of LEDs.

I chose the starting point to simplify wiring (neat wiring? sorry for my English)

Therefore, the data line by LAN cable, and the power line from power supply start at the same point.

Once the wiring is done, I rearranged lines to be neat.

I used double sided tape to place Teensy board and nuts & bolts to place power supply.

STEP 7: Mount Screen

I decided to use rail wires to hang the screen.

Place the guide profile on the wall, and hook the screen using the wires.

Luckly, the wire hook fits to the aluminium profile side hole (near LED strips).

STEP 8: Upload "Adalight", Set by "Ambibox" and ENJOY



Basically, I followed this instruction : https://youtu.be/oCoPgSwmoQc

You can refer to "Software installation" in the instruction.

After all setting is done, you can enjoy it!

My projector is also made by me. It has 1920x1200 resolution. If interested, u can see the build log here!

26 Comments

jmigoliva 6 years ago

Hello, your post inspire me to do the same project.
I have a question, is it normal for the leds not to work correctly if they are not connected to the tens?
Thanks.
José Miguel

vrwired 7 years ago

First off... great job. I am thinking about going this route with a 55" tv. May not need the Octo for performance, but hey, It can't hurt right?

QUESTION:

How did you deal with the unordered LEDs? You never say. You say Ambibox does not support unordered LED's... did you change the layout/wiring so that it was ordered? Once again, GREAT JOB! Please post how you dealt with the unordered LED's. Thanks

rundmcarlson 8 years ago

You should really think about putting a bit of diffusion on the LED strips so that you don't have this super bright edge with huge fadeoff like you currently have. If the strips were covered in a diffuse layer, the wall would have a softer gradient, which would more realistically mimic the blurring effect of depth of vision. It looks like the edges are even brighter than the initial projection, which seems like it would take away from the experience.

bumhee34 8 years ago

Yes, diffuser would make this more fancy. Anyway, I can control ambilight brightness via Ambibox, and the pictures and videos were taken with enough brightness to show how ambilight works.

Another option is to change the projector into more bright one. As my projector is DIY, the brightness is really poor.

At this moment, I am satisfied with my current setting. (I've changed the brightness for real usage)

Obviously, I will update if I use a kind of diffuser.

rundmcarlson 8 years ago

Either way, good job and I hope you enjoy it. I am planning on doing one for my living room TV once my house is put back together (I just moved) and this gives me another option. I always like to see how different people set up their projects so I can kind of mash them up into what looks like the most effective solution for me. So thanks for the information!

DonD10 8 years ago

This was my exact take-away. I don't own one, but I got the impression Ambilight was intended to be somewhat subtle. Really, really neat project, but one small tweak could make all the difference (I'm wanting to do one that also integrates sconces in the room, but I'm still early in the design). I'll be watching this to see if this get updated!

colby.westerfield 8 years ago

I'm unsure on how you are inputting the video signal into the teensy.

In many of these projects its a low resolution capture card or being restricted to kodi. I'm do this immediately if i could get a hdmi input to work.

Can you elaborate on how the video gets in?

bumhee34 8 years ago

teensy is directly connected to PC. And Ambibox sends the signal from PC to teensy.

colby.westerfield 8 years ago

Dang! I was afraid of that. I hope someone is working on a hdmi capture arduino or some such. That would make it for me.

kocurmatus 8 years ago

Great job, bumhee34!

However I'm not sure you have mentioned how video signal is sent to Teensy/Octo. What type of connection is used as video input? How the LEDs know what picture you have on your screen? Thanks

bumhee34 8 years ago

Hi.

It would be better to read this link : https://learn.adafruit.com/adalight-diy-ambient-tv...

In short, Teensy (or Arduino or whatever) is not connected to any video cable, but it is connected to a computer by an USB port.

Not sure about this part, but I guess Ambibox sends "captured color signals" on the edges of computer screen (in my case, projector. projector is connected to my computer). Then, Teensy emulates the ambilight function based on the captured color signals.

Basically, Teensy communicates with a computer via USB cable, not video cable.

With my setting, it is impossible to emulate the ambilight with an arbitrary video input like xbox, play station, or blu-ray player. To emulate the ambilight for any kind of video inputs (hdmi), you need more steps to send video signals to Teensy or Arduino. In this case, you may need Raspberry PI as far as I know. However, this is not my area, sorry.

Someone may help you!

Glawford 8 years ago

Great job!!!

By the way the "joint parts" you have here are a "cast corner bracket".

Again great job!

bumhee34 8 years ago

Thx for your correction! I will update it later.

windoz 8 years ago

Very cool, but I don't feel so smart looking at most of the Instructables on the site!

windoz 8 years ago

Very cool, but I don't feel so smart looking at most of the Instructables on the site!

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