Steve and others,

I'm still having a problem getting my display brightness set correctly.  I want to use the dimBus with the AviCurve.  I want the display to be 100% bright when the dimBus is at 0V, but then as I increase it, I want it to go to the minimum and then ramp back up to 100% at the max dimBus voltage.  The following photo shows what I want to accomplish:

I have set the min dimBus voltage to 0, and the max dimBus voltage to 12.9.  I set the dimBus minimum to 1 and the dimBus maximum to 100.  When I turn the dimBus all the way to the max (12.9V in this case -- on the ground, engine running at idle), I only get 21.3 on the display.  I want 100%.  How would I set this up?  What exactly is the equation?  I have played with the slope value, and in this case have it set to the maximum of 100.  Either I'm doing something wrong, or there is a bug in the system.  The maximum is set to 100, but I'm only getting 21.3.  What gives?  See this picture for the settings.  When this picture was taken, the dimBus was just adjusted to the maximum setting which was 12.9V at the time.  This picture was very, very dim and hard to read.  I had to enhance the brightness and contrast prior to posting to be able to read the values.

Steve, can you please look into this?  Or at least explain why I can't get 100% brightness?

This is my second IFD-540 (my upper right knob was bent when I got the unit back from the factory with mods, so I now have a factory exchange unit.).  Both units behaved the same with respect to the brightness issue, so I don't think this is a one-off issue.  It's probably operator error, so please tell me where I'm going wrong....

Paul B.

This really feels like a bug in the system, but not one other user has chimed in with a similar experience, so perhaps it is operator error.  If I can provide any further information I will.  Just let me know.

<deleted>

When above the min dimbus voltage, I would expect the equation to look something like:

Display level = (dimBus voltage)/(dimBus max voltage) * (dimbus Maximum)

Of course, there is the dimBus slope in there, too.  I have that set to 100.

I just need someone at Avidyne to show the equation so I know how to set the parameters.  Or perhaps to fix the equation if there is a problem with it?

I didn't see your post before I posted mine.  It wasn't in response to yours.

I suppose if the transition is set to 1 or 2, that when I dial my dimBus voltage down to zero, the brightness will revert to the photocell?  I guess that would work, but I would still need the proportional to be able to be dialed up to 100%.  I will try that and report back.

Have you gotten yours working yet?  I think I'll want AviCurve instead of proportional because proportional requires me to have the radio lights on full blast all the time to have the 540 lighting turned on.  I only turn on the radio backlighting when it's dark out.

Until I remember to spend some quality time in the dark with it to see if I can figure out the magic settings, I currently have all the automatic settings overridden and am dialing in the dimmer manually via the "user setting" option, which is somewhat annoying.

* Orest

I encourage you to share the settings that are working for you.

Regards,

Bob

I feel a little better now that others have chimed in...

Avidyne -- What's going on with this?  Why can't we get full brightness?

 

Are those lights binary on/off without dimming capability?  That would seem odd in this application, but I'm trying to understand the design concept.

Steve/Simpson, 

Has anyone at Avidyne had a chance to look at this?  It's been 6 weeks since I posted, and over a month since Steve said he might need a week for a response.  (I don't count responses from Orest as official Avidyne responses ;) )

I realize there is a push for 10.1, but that shouldn't shut down technical help for actual users right now.

pburger

I just spoke with tech support about your settings and what you are looking to accomplished. They recommend adjusting your dimBus Transition % from 10 to 50. There is a proposed software change that will effect the AviCurve but I don't have the exact details on that.

-Simpson

I changed the dimBus transition to 50, but that had no effect on my original issue, which is that the display will not go to full brightness when on the dimBus, and turned all the way to the max voltage.  It only goes to 21.3%. 

AviSimpson, do you know if the proposed changes are part of 10.1?  This has been an issue for a long time and should be an easy fix.  I don't recall seeing any argument from Avidyne about why the current design has merit other than work around suggestions so I'd like to think this one isn't under debate.

The jump to bright as the dimmer is turned down is to allow the unit to be full bright when the lighting is turned off.  The transition can be adjusted.  If your lighting works differently, you can use the proportional setting instead of the AviCurve.  The missing area issue is that using the AviCurve, the unit can't get bright enough during the day.  This makes you rely on the sensor and transition settings, which is not ideal.

Now that 10.1.0.0 is out, when can we expect a "comprehensive answer" to my original question?

We agree that the dimming controls when not set to “User Control” are hard to use/understand.  It took us quite a while ourselves to understand it as we developed it.

The reason all the parameters exist and the complicated relationship between them exists is that our premise when designing the lighting controls was that there were 140,000 installed 530s and 430s and that installers (and owners) have been using them for many years and would be familiar with it. Rather than inventing a whole new scheme, we chose to use the one that we thought the dealer and owner market have been using and learned.

Had we designed our own, there would have been no way we would have picked this.  Nevertheless, it’s what we chose and what we now have.

We did add the 2^nd curve (the “AviCurve”) at my insistence since if I really were using the cockpit dimming rheostat(s) control to set cockpit dimming, a typical behavior would be to set it full off in daytime flying.  In that case, I wouldn’t want my bezel and display to be fully dimmed, hence that jump up to full daytime brightness when the dimming rheostat is very low.

As a review, here is an excerpt from the 540/440 Installation Manual for dimming controls below.  I’ve highlighted an important section that talks about the transition point and a recommended technique to use to avoid one operational gotcha that some folks have noted when they have the “Mx Input” field = Photocell:

+++++++++++   IFD540/440 Installation Manual snippet  +++++++++++++++++++++++++

If the 'proportional' curve went to photocell on 0V (or near) the system would be a lot more usable than it currently is.

AviCurve needs to respond as the majority of other avionics systems do or it won't be used, i.e. full volts - full bright.

Any broad guess as to when a lighting update would come out of the pipeline so we can update customers?

Steve,