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Screen Dimming
#1
Just noticed my screen doesn't dim.  I've tried manually dimming it as well as played with auto dim with no luck.

Any suggestions?
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#2
Oops sorry about that, I meant to post something on that.

A couple weeks ago I also realized my displays weren't dimming, it turns out there's a small resistor on the back of the display that has to be moved.

Find the area in the image below. It says "Backlight Control" and has 3 rows of resistors.

The top row (R14) says "PWM_MD070SD" and has the resistor.

The next row (R12) says "LED_A" this is where the resistor above needs to go.

Put the soldering iron on one side of the resistor for about 2 seconds, then quickly go to the other side and push it off the pads. It might stick to the soldering iron so flick it so the resistor falls off, just don't lose it. Then solder it to "LED_A" and it'll work. Sorry about this, of course any new ones going out now have been switched over.

Anyone else who has a display from me and it doesn't dim this is what needs to be done.
[Image: display_backlight.jpg]
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#3
Worked, thanks Rob!

Is there a way to set it up so the screen goes to sleep or will it always be on?
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#4
Glad to hear. I'm working on the update so I'll make changes so it dims completely, good idea.
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#5
slide show would be nice when it dims got tons of room on my SD card can we maybe have a extra folder on it for my-pics or some thing then have an option to dim down and stay there or go to slide show and just pictures out of that folder.
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#6
Rob, would it be possible to possibly lock the screen and require a pass code to access or make changes? Maybe even use a combination of the icons along the bottom. For example if I press settings nothing happens but if I press power, settings then power again the screen is enabled and back to normal. A four digit pass code would also work.

The reason I ask is that I have a 3 year old who loves to touch and play with things, this way she can't change any settings on the controller.

Just a thought.
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#7
I know you want that slideshow rott, it'll come. :)

Another good idea, different, maybe I'll have to see how much space is left when its all said and done, I'll know in a week or two if I can.
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#8
I was thinking if you did have a slide show and people wanted the screen to fade out you have the software shipped with a black .jpg or .raw or what ever it would take if the blak.raw file was the only one there then it would fade to black or just go to black sense it is the only pic it would just stay black but then as you add pics it would start to change to the others don't know if that way is any better
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#9
I think its better to dim the display if someone wants it black as it'll use less power and maybe last longer.
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#10
so what if you have it on there all ready do I need that diode you sent to me hooked up some where or does the software just autotmagicly do it??
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#11
The dimming code works but you do need that photocell resistor added to the top of the display board at the top of the screen. You'll probably want to extend the sensor so it sees the outside of the housing for the display, that's why I didn't solder it. Polarity doesn't matter.

[Image: photocell.jpg]
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#12
ok wasn't sure if I need that or not

exactly where does it go? the display board is the one with the LCD connected to it wright?
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#13
Yeah the display board has the LCD attached. You need to solder it to R12 on the board, its right above the due at the top of the board.
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#14
I have a resistor for LED A (manual dimming)
You hear a "squeak" of Arduino DUE
Any suggestions?
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#15
Hi Irass, that's where the resistor should be, it should dim.

Not sure what you mean by hearing a squeak? I've never heard anything from an arduino.
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#16
squeal excitation of induction coils
can be heard loudly dimming 18
quieter 10
PWM frequency can be heard?
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#17
How old is your Due? If its working it shouldn't matter.
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#18
he is hearing the buzz sound from pwm people some times hear from LED driver when dimming lights it is like a high pitch whistle sound I have never heard it but others do
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#19
I connected the POWER LED PWM driver, or squeal with driver
(Induction, may increase the frequency limit of hearing)
driver parameters:
- Operating frequency 250kHz.
- The input PWM can control the brightness of the LEDs
from 100% to almost "0" at a frequency of 1 kHz or
even higher
or squealing with you?
which have LED drivers?

sorry for my bad English.
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#20
Irass can you post pictures of what you are doing
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