Red backlights do not turn off

[jhansche]

The backlight behind the knobs and physical buttons on NR5261 (Carpad III for VW) never turns off. The display turns off after you turn off ignition, remove the key, open the driver side door, and then ~3-5 seconds delay. But the backlight behind the two knobs and 5 physical buttons (on both left and right side of the display) remain on, even 12+ hours after turning off the car.

So far this hasn't been an issue, presumably because the lights are low-power LEDs. But when the car is off and the headunit is off (or in standby), the LEDs should also be off.

I haven't started debugging anything yet, to see if the lights can turn off using a /proc or /sys dev node.

It's worth pointing out that I installed xdAuto (self-built) using the update.zip image on the SD card - not using the rkbatchtool (no windows machine, and no USB A-to-A cable). I don't think that would have had an impact, but I suppose it's possible.

Also note that this same problem was happening even with the stock image from Newsmy. I was hoping that xdAuto had fixed it, but does not appear to be the case.

[jamesgol]

I don't have a NR5261 (or anything hooked to Canbus, which presumably yours is). I'm certain that messing with anything in /proc or /sys will have no effect. I suspect the right place for this to be handled is in the MCU code, but since we don't have access to that you would have to find an alternative.

Probably need to send a command over serial on standby (possibly mcu_pickColor 0x83 0x0A) to change the color/brightness.

If you use the MCU settings and try to change the color are you able to make them turn off?

[jhansche]

I haven't tried the MCU Settings to change the color yet - I will report back when I have a chance to try that.

Unfortunately I don't have a workbench setup for this unit, so all the work I've been doing has involved lugging a laptop and my phone out to the car D:

[jhansche]

@jamesgol thanks for the tip. I got a chance to play around with different parts of the Backlight Keys section of the MCU app, and you're right: the brightness of the keys backlight is actually controlled by the value of the blue channel in the keys RGB setting. The red and green channels are completely ignored, but the blue channel will change the key backlight's intensity (0=completely off, 255=full brightness)

So the next thing I'll look into doing is catching the event when the screen turns off, and also request the MCU turn off the backlight by setting that blue channel to 0.

What's the best way to do this on a per-device basis? I'm assuming that other devices (whether NU or NR models, as well as various models within each generation) probably work slightly differently with this setting. I.e., how does your device react to the Backlight Keys values?

[jamesgol]

I had been asking Newsmy for the MCU to send over some kind of hardware ID string but nothing ever came of it. The next best thing was going to have a configuration settting in the MCU app to set what type of device it was so different features could be enabled/disabled based on that type. Never had time to implement that.

[jhansche]

Gotcha - makes sense. If you want to give a rough outline of what you were thinking, I can work on implementing that.

We may need to strike a balance between having a simple "choose your device model number" (which can know everything there is to know about each model and what can/can't be supported), vs "choose which behavior you want to enable for feature_xyz" (which requires that the user knows what features his model can/can't support, but gives more flexibility to allow the user to choose, and removes the need for us to maintain a huge list of model-to-feature mappings.

It would be nice if the only differences among all the models is in NU vs NR.

[jamesgol]

My thoughts were having a select box with the various model types and at the bottom of the list would be custom/advanced. Underneath would be a series of checkboxes for the various capabilities that would be display only unless custom/advanced was selected.

It's been a while since I've worked on the devices so I don't recall all the differences that would matter. One of them for sure was only having a slider for brightness on devices that didn't have the multicolor backlights.

[jhansche]

I've added the first iteration of configurable "Capabilities" and presets. So far nothing makes use of those presets, but we should be able to update the Backlight Keys fragment to use it, and add more capability differences between the two.

A future iteration would ideally be able to detect the capabilities, but I don't know yet if that's even possible.

[rtrev2442]

I realize that this thread is nearly a year old, but did anything ever come of this issue? I just installed an NR5261 myself, and I'm experiencing the same issue with the backlights staying on when the unit enters standby.

[jhansche]

@rtrev2442 from our email discussion, it sounds like you found a resolution. I haven't tried your suggestion yet, and I don't remember how mine was connected -- whether I attached the illumi wire or not. From our email discussion:

I'm not sure which VW model you are using this radio in, but regardless of that, your NR5261 should've been supplied with the quad lock harness to provide a plug and play installation. On my wiring harness, there were a few wires that are split in the middle with a bullet connector. Two of them were attached already when I pulled the harness out of the box; one labeled "Acc" (red), the other labeled "Illumi" (orange). All that needed to be done in my case was to break the connection on the "Illumi" wire. I borrowed the below image from a google search to illustrate the connectors, in this picture, the two aforementioned connectors are disconnected.

This works presumably because the trigger for the radio illumination on our Volkswagens is handled via CanBus. As long as all of your other CanBus functions are operating properly on your unit, it should be able to handle the illumination as well.

This makes sense to me, and I'll follow up when I have a chance to check if mine is connected or not. If it is, I'll disconnect it and test again. If that's the fix, this can be closed.

[rtrev2442]

@jhansche Thank you for adding this here. I have seen this issue pop up across some other forums, and I hope that my findings will benefit you and those others that are experiencing the same issue.