Czech mirror in IKEA LILLÅNGEN

Mitchfarino

How are you controlling the backlight?

Could you share how this is done, please?

TomasZmuda

Of course, first I tried to control backlight by raspberry gpio. PIR send signal to raspberry, and by some python script open NPN bipolar tranzistor which turns backlight on.
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But there was a problem with hight current, and any other problems.

In the invertor the are 4 cables: ground, brightness 3,1-3,5V, backlight 5V, power 12V.

Fortunately the backlight si possible to control via any voltage (not any, but 3V-12V is ok). The PIR has output 5V, so I connected the output from PIR directly to LVDS converter. Be carefull, you have to hook up the groud in raspberry and in LVDS!

sero

Hi Tomas,

your mirror looks great!

I´m planning to do the same (and I even looked at the same Ikea mirror :) ) and was wondering how you solved tha backlight handling exactly.

You talked about an invertor in one of your posts. My controller has an invertor, too. Can you tell me if your solution would work here aswell?
This is the board with the controller: http://www.ebay.de/itm/TV-HDMI-VGA-AV-USB-AUDIO-control-board-for-15-6-B156HAN01-2-1920x1080-IPS-LCD-/361128251020

Thanks :)

TomasZmuda

Hi Sero,

your inventor has 6 cables, so one of this should be backlight controller. I can’t help you more, you have to measure it by voltmeter or oscilloscope.

Tomas

sero

Thanks Tomas,

unfortunately I don’t have a voltmeter or an oscilloscope at hand. I hope I’ll figure it out somehow :/

Sebastian

KirAsh4

Without the proper tools or instruments, you have to be really careful that you don’t short out the inverter or cause other damage.

sero

I found the description of the board and pins:
http://www.vslcd.com/Specification/T.VST29.03.pdf

“CN2” describes the pinout for the invertor.
Pin 3 is backlight on/off and pin 4 is for the adjustment of the brightness.

TomasZmuda

Perfect, you could only unplug this cable and the LCD shound be without background. It’s simple test. :) Next plug this cable to PIR output and as i wrote in first post, don’t remember hook up ground between LVDS and Raspberry.

MrH

I just posted a question about PIR connection to a similar board. Feel free to help me out guys :)

https://forum.magicmirror.builders/topic/503/pir-sensor-to-cut-backlight-power

@TomasZmuda if you look at my option 2. do I need to ground inverter and Pi?

thanks!

sero

@TomasZmuda
I tested unplugging pin 3 and you are right: the display / backlight ist switched off 👍
I also got me a voltmeter and checked the currents :) seems to be identical to your setup. So next, I’ll connect a PIR, check the current and connect it as you described.

Thanks!