Display extended 7", minor problem involving button LED's

Posted by: Narkotic

Display extended 7", minor problem involving button LED's - 19/11/2005 02:10

I'm working on a project for my car, it's in it's final stages of completion. I contacted "coolblue" on here, he created the aluminum housings for our players years ago. I was interested in the 7" display extender PCB that he had made, he had enough parts left in his cellar to make me one.

Click here for a picture

Now I know all the precautions about extending the display, etc etc. The extender works GREAT, minus one issue. When I enable my button LED's (eutronix light kit), it gets pissy. The lights flicker, the display goes dim and bright and the player isn't very responsive. As soon as I disable the lights, everything seems fine.

Could this be a current issue? Anyone care to chime in and explain technically what could be going on here?

Much appreciated
Posted by: Shonky

Re: Display extended 7", minor problem involving button LED's - 19/11/2005 06:16

Possibly the power supply is a bit borderline and extending the cable results in a slight voltage drop on one of the supply lines.

Having said that though, I would have thought the empeg guys would have designed in enough overhead that 7 extra inches of display cable wouldn't have made much difference. Turning on the LEDs will be adding some extra load. Again I would think there'd be enough overhead designed in.

Another possibility is external RF is somehow affecting things but your description implies power supply issues. Alternately, the power supply issues together with the extended cable cause it to be more sensitive to RF.

I'd be looking at the supply lines on a CRO/DSO myself but you probably don't have that sort of equipment available to you.
Posted by: mlord

Re: Display extended 7", minor problem involving button LED's - 19/11/2005 12:05

Is it any better when the buttons are dimmed in Hijack?

I would try running an extra ground wire directly to the display board. Just take some 'gator clips and try it first.

Cheers
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 19/11/2005 19:53

Yeah, regardless of the dim level in hijack it does it.

Where do you sugest I ground to on the face? I was thinking of doing the same.
Posted by: mlord

Re: Display extended 7", minor problem involving button LED's - 20/11/2005 12:55

Quote:
Yeah, regardless of the dim level in hijack it does it.

Where do you sugest I ground to on the face? I was thinking of doing the same.


I don't have a unit handy to examine right now, but the base of the rotary encoder (the knob thingie) should have a grounded collar, just where the twistable knob shaft joins the solid parts.
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 20/11/2005 17:45

Interesting.. I set it to max and they work fine. It's only when I have them dimmed. I hooked a volt meter to the leads, the voltage fluxuates up and down irratically (when dimmed)... any ideas?
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 21/11/2005 02:32

How about this?
Posted by: mlord

Re: Display extended 7", minor problem involving button LED's - 21/11/2005 13:53

Bad link. Sort of. Click on Page 1 2 All to see the content.
Posted by: mlord

Re: Display extended 7", minor problem involving button LED's - 21/11/2005 13:56

Maybe needs the "dimmer capacitor" trick to reduce noise on the signaling line?
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 21/11/2005 16:22

The reason I used that link was to take you to the page about the cap 10nf fix. I will try to source one of these and throw it on there.
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 22/11/2005 02:24

Well I put the cap on, it seems to have fixed the dimming issue of the display, however I still need to leave the buttons lit at maximum level.

how do you control the LED's through the software?
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 22/11/2005 15:32

Update: Everything seems to stay fine as long as I leave everything at 100% (dimmer/button LED's). Even if I change the dimmer to a lower setting it freaks out and goes back to where it was. Shouldn't be a problem, i'll just leave it at 100% for now.. But it would be nice to figure out why it does this.

Keep in mind this is only w/ the display extender. I tried grounding the display, no luck. Could it be some sort of signal latency? I wouldn't think so considering the dimmer chip is on the display board itself, and the extension is only about 7".
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 23/11/2005 03:09

UGH I spoke too soon, it still happens although not as much. Does ANYONE have any ideas??
Posted by: tfabris

Re: Display extended 7", minor problem involving button LED's - 23/11/2005 16:12

My only idea, and I've been holding off saying anything until now, is that the extender device has some kind of a fault (or design limitation) that prevents the button LEDs from working properly.
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 23/11/2005 16:25

I'm seeking something a little more technical than that... like noise on the line, timer latency issues... it's not just the buttons, i'ts the display dimming when the button led's are enabled. It seems that they are drawing alot of current and it causes the display dimmer module to fault.
Posted by: maczrool

Re: Display extended 7", minor problem involving button LED's - 23/11/2005 18:55

Perhaps you should look at the signals with a scope both with and without your extender. Look at them both with and without the LEDs on.

Stu
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 23/11/2005 20:23

good idea... now to find a buddy w/ an o-scope..
Posted by: mlord

Re: Display extended 7", minor problem involving button LED's - 23/11/2005 21:23

The original dimmer-cap thread describes the (most likely) problem rather well.

Yes, there's a timing issue -- it's right on the edge with most players, and extending the cable could be enough to trip it up.

Cheers.
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 24/11/2005 01:51

Now let me ask you this mark... is there a way to have the player set the display brightness to 100% after it is all booted up and playing music? Sort of like how it brings the visual back in the car?

Just to "make sure" that it is at 100%.
Posted by: Shonky

Re: Display extended 7", minor problem involving button LED's - 24/11/2005 02:23

Quote:
Now let me ask you this mark... is there a way to have the player set the display brightness to 100% after it is all booted up and playing music? Sort of like how it brings the visual back in the car?

Just to "make sure" that it is at 100%.


Just go to the dimmer menu. Keep turning it up. It will go bright and dim, but it's pretty obvious what is 100%.
Posted by: Narkotic

Re: Display extended 7", minor problem involving button LED's - 24/11/2005 04:28

Thats a hassle... i'd like to have an option in hijack or something where it will do it automatically each time it boots up after the visual is selected. Something like "set dimmer and buttons to 100% after bootup"
Posted by: mlord

Re: Display extended 7", minor problem involving button LED's - 28/11/2005 01:12

Try a larger (value) capacitor for the "dimmer fix"
(?)