Backlight control via logic

Hi,

I would like to achieve the following, applicable to the Colour Touch or Spectrum (with Logic):

I have set up the unit so that the backlight goes off once the room gets dark. That is fine.

When a specific GA goes on, a specific page is displayed. Also that works fine.

However, as the backlight is off at night, the page isn't visible.
I have serched through the Logic Manual and the forum, but could not find a way in which I could get the backlight to switch on from within a logic module (the same one that also brings up the page).
Is this possible at all?

My apologies if this has been dealt with previously.

 

You can solve this easily on the Spectrum as it has the proximity detection feature. You can configure it so that when you wave your hand in front of the unit it will wake up the display.

Another approach is to not use a lowest level of off, but use a level that just has the display glowing. For a Spectrum, I find that the lowest level that makes the screen glow is 6 steps above minimum. To set this, go to the Backlight tab of the Project details form in PICED. Select the vertical Min slider and set the slider position to the minimum, i.e. 0. Then, click the up arrow 6 times. The value underneath the slider should say "Min 2". This is the lowest setting where the screen is actually on.

I have this set-up personally and have the screen showing a clock at night time with a black page with white text. It glows very dim and is low enough not to be noticeable. When I wave my hand in front of the screen, it brightens up.

 

To switch the backlight to its "bright" setting, use this logic code:

Code:

ExecuteSpecialFunction("Backlight Bright", 0);

 

Thank you Gents for your replies.

Newman, that is good advice, I forgot about the proximity settings. If there was no code to get it sorted, then that would be a good alternative.
As regards a minimum visible level, we had that, but as we are out in the country, even that is a bit too much, hence it's set to OFF. A client of mine has a similar problem with his DLTs in the Bedroom.
Funny how a tiny bit of light is too much when its dark and your eyes are used to it, and how a lot of light during the day is sometimes not enough.

Darren, I did try that code, but I didn't come across the ",0" in the documentation. May I ask what this is in aid off? Could one increase the light level by using a larger number?
I'll try this, and if it works, that will be great, as in this application I really would like the screen to come on automatically.

Thank you both again for your help!

 

A good trick is to make your page background black, with white writing. That makes it emit a lot less light.

In this case the ",0" does nothing. The ExecuteSpecialFunction procedure requires two parameters, but the second one is only used in some cases.

 

Thank you Darren,

Works like a charm!