Locus Map Gold is too dark

[JackRussel]

I have now received the update to Android 13.
Unfortunately, nothing has changed.

The brightness and the speed of the dimming did not improve.

I must therefore continue to do without LM4 and hope for long support of LM3 by Menion.

[Wole]

I use the Oppo Find X2 pro as a bike sat nav because LM4 doesn't run properly on most Samsung devices.

Now my Oppo receives the ColorOS 12.1 software with the information that overheating protection has now been installed. According to the description, apart from a few apps, all the rest should be shut down when a certain temperature is exceeded.

Then it seems that the other manufacturers of smartphones are gradually following Samsung's example, so that it can be foreseen when LM 4 is no longer useful.

I will not import the update for the time being and have asked Oppo at what temperature the function will take effect.

[Wole]

I have now received the following answer to my request from Oppo about installing the overheating protection:

"When the temperature of the device reaches around 40 degrees Celsius, appropriate temperature control measures and strategies are taken. This is mainly to protect the battery to prevent damage to the device and battery.

If you receive a corresponding warning message or the device switches itself off, it is advisable to let the phone cool down before continuing to use it."

The Oppo reached temperatures of max. 44 degrees outdoors in summer. This means that the use as a navigation system for LM4 is so severely restricted that I will not import the update in order to be able to continue using LM4. This information for other users to decide how to deal with this issue.

[svartbjorn]

I do not have this dimming issue with LM4 on my Samsung S22 Ultra running Android 13.

[Wole]

Since the post was reopened in the German forum, here is my answer in case it should interest one or the other:

"It shouldn't be the problem of a navigation app. I had already rummaged through all sorts of German and English-speaking forums. At least with Samsung, the problem also affects other apps, such as e-mail apps, etc.

If it only affects the navigation apps, the question always arises, why only LM4, why not LM3 as well? So I agree with JackRussel that Menion is accessing some function in LM4 that is causing the problem.

Thank God I was able to deactivate the function on my S 21 Ultra in good time via Alliance Shield. All firmware updates have not changed this, thank goodness, so I can currently navigate with the device and LM4 without blacking out.

What surprises me, however, is that these problems are not still being reported here or in the English-speaking forum. It shouldn't just be the Samsung devices that are affected, right. I also use an Oppo Find X 2 pro as a navigation device. A firmware update with the great improvement "automatically switches off the display if it overheats" has been offered here for months.

When I asked when the protection would take effect, I received the following message from Oppo "When the temperature of the device reaches around 40 degrees Celsius, appropriate temperature control measures and strategies will be taken."

Before that, there was the following message without temperature information: "If the device is exposed to high ambient temperatures and performance-intensive applications are run, the device may heat up more."

It follows for me that when dimming, the firmware distinguishes between "power-intensive and non-power-intensive applications." So it may be that LM3 is not performance intensive and LM4 is performance intensive, whatever the difference.

Of course I haven't updated the firmware, so I can currently run LM4 on both devices without any problems.

But how it will work with new devices later, when the devices are getting old, remains the exciting question.

Finally, the question: Has anyone ever tried to factory reset a device with current firmware on which Alliance Shield can no longer disable temperature protection and then before updating the firmware to the current state, the protection turn off? Because as I said, once deactivated, the protection apparently remains deactivated even with the latest software. "

[Menion]

Thanks @Wole for the additional info.

I'm still unable to find any reason for this behavior, sorry. The core of both apps is still identical. We also tried even a basic clean app install and the result is the same. Also, it does not happen on any devices we currently have.

Complicated and still unsolvable issue 

[Menion]

Hi guys,
this topic is heavily discussed in German topic and I would like to do something with it, of course. But still not sure what. Because my Pixel 5 is close to the end of its developers lifetime (no more updates after Android 14, but the device will of course serve a few more years in our team), the best should be to purchase a device that will have this problem as well, so I will be able to test and play with it.

What devices suffer by this? Samsung devices, but any other? Has anyone experienced with the new S23?

[Wole]

Hello Menion, did you find the problem in the meantime?

[Menion]

Sorry Wole, no. No one in our team has any idea regards this problem.

[Wole]

Hello,
I'm coming back to the old post.

As my cell phone is getting old, I'm currently considering buying a used Samsung S 24 Ultra.

Did anyone use this cell phone on their bike last summer? Does the dimming problem also occur with this Samsung?

[Wolfgang]

Hi,
I have Locus Map 4.33.0 since a few days and I have the same problem with dark display. I never had this with Locus Map Classic, which I used since 2012. In sunlight the display dimmed in about 1 minute.
In Locus 3 everything is OK. I use S24 FE. It`s very hard to follow the right track.
Greetings
Wolfgang

[Menion]

Hi guys,
I've let AI analyse source codes of old Locus Classic and new Locus Map, search over the web and do some bigger analysis ... here is the result ...


What's happening

Samsung devices include a hidden system service called SDHMS (Samsung Device Health Manager Service, package com.sec.android.sdhms). Among other things, it has a "Brightness Limit" feature that reduces display brightness at a hardware level — below the Android brightness API. This is why the brightness slider stays at maximum (255) while the screen visibly dims to roughly 200 nits (~30% reduction). The normal brightness API has no idea this is happening.

This is the same mechanism that users previously fixed using Alliance Shield X — those "two hidden switches" were the SDHMS settings "Brightness Limit Off" and "CP TM Off".


Why LM4 but not Classic?

Samsung also runs a service called GOS (Game Optimizing Service) that downloads a list of app package names from Samsung's servers and applies throttling to them. In March 2022, it was publicly revealed that GOS throttles over 10,000 apps — not just games, but also Instagram, Netflix, Google Keep, and even Samsung's own apps like Samsung Pay. The throttling was proven to work by package name: a Korean researcher showed that renaming an app's package to match a throttled app immediately triggered the restrictions.

Both LM4 and Classic share the same core rendering code. The only significant difference is the package name: menion.android.locus (LM4) vs menion.android.locus.pro (Classic). If Samsung's server-side list includes LM4's package but not Classic's, that alone would explain the entire issue — same code, same device, different behavior.

This also explains why:

• Google Maps is also affected — it's likely on the same list
• TwoNav/OZI are fine — smaller apps, not on the list
• Some Samsung devices are immune — different firmware versions carry different lists/thresholds
• Android/One UI updates sometimes help — Samsung recalibrates thresholds with updates
• Non-Samsung devices are never affected — no SDHMS/GOS

How to verify (for affected Samsung users)

If anyone with the problem is willing to test, here are two approaches:

Option A — Check if SDHMS brightness limit is the cause:

• Install Shizuku (https://shizuku.rikka.app/) — requires enabling USB Debugging via ADB
• Install System UI Tuner from Play Store
• Through lock screen shortcuts, access the SDHMS thermal settings
• Toggle off "Brightness Limit Off" and "CP TM Off"
• Test LM4 in direct sunlight

If brightness holds steady, we've confirmed the cause.

Option B — Check if GOS has LM4 on its list:

Connect your Samsung device to a PC with ADB and run:
adb shell dumpsys package com.samsung.android.game.gos
Look for any reference to menion.android.locus in the output.


What can be done from the app side?

Unfortunately, there is no Android API that lets an app opt out of Samsung's SDHMS brightness throttling. The throttling happens at a layer below what apps can control. Possible paths forward:

• Contact Samsung developer support to request removal of the package from any throttle list
• Expose a diagnostic in LM4 that reads PowerManager.getThermalHeadroom() (Android 11+) so users can see if Samsung is reporting thermal pressure
• Document the workaround for affected users (Shizuku + System UI Tuner method described above)

If anyone can run the tests above and share results, it would help confirm whether this is indeed the SDHMS/GOS mechanism at work.

[michaelbechtold]

What a nightmare ...

Did you use Claude Sonnet/Opus 4.6? Or which other AI?

[Menion]

Yes, Claude Opus 4.6 analysed this.

---

I also wanted to confirm to myself that there is nothing wrong with the code we did.

At least, I'm still after five years, unable to find a difference, and AI "confirm it".