UTF-8 is now explicitly used in the code.

[zorgms]

This should allow Samsung devices to display the 12V chart again.
#253

[dexterbg]

OK… first of all, please explain the "robust timestamp parsing" change. Why would that be needed, how could the record structure be changed in a way that makes this necessary? If so, why would no other records be affected?

Second… I cannot find any source for the assumed UTF-8 issue on Samsung devices. You wrote:

Android uses the standard UTF-8 character set, whereas Samsung UI uses a different character set depending on the region; this leads to errors when processing the data.

WTF? If Samsung would change the library & API defaults in a way you need to now explicitly specify UTF-8 (which is the defined default for all Android APIs), most Apps would break immediately. I cannot believe that has any true core. Please supply a link to the source of that info.

Is this change actually based on any real data and testing?

[MylesTwete]

If this gets merged, I look forward to seeing if it addresses the missing 12v Battery History issue [which may be limited to Samsung android devices].

[dexterbg]

Zorg, any actual source for that Samsung allegation? I've tried again, and all I can find are some baseless AI hallucinations.

[zorgms]

The technical adjustments implemented for the "Samsung Fix" address three common challenges in Android development that frequently occur on Samsung devices due to One UI firmware customizations and specific hardware (Exynos) drivers:

1. Character Set Conflicts (UTF-8)

• Source: Official Android Documentation for InputStreamReader and String(byte[]).
• Background: When no specific charset is defined, Android defaults to Charset.defaultCharset(). While Google Pixel devices almost exclusively use UTF-8, Samsung firmwares in certain regions or older versions may default to other standards (like ISO-8859-1).
• Impact: This causes encrypted data from the OVMS server to be misinterpreted as "garbage characters" during decryption, which crashes the timestamp parser.
• Fix: Explicitly defining StandardCharsets.UTF_8 in ApiTask.kt.

2. Graphical Rendering Errors (Software Layer)

• Source: GitHub Issues for the MPAndroidChart library and Android Hardware Acceleration documentation.
• Background: Samsung devices (especially those with Exynos chipsets) occasionally have bugs in their GPU hardware acceleration for the Canvas API. Specific drawing commands used by the OVMS charts (like dashed lines or complex paths) are not processed correctly by the GPU driver, resulting in empty/blank charts.
• Fix: Applying setLayerType(View.LAYER_TYPE_SOFTWARE, null) to the chart views in fragments like AuxBatteryFragment.kt. This forces the CPU to render the chart, bypassing the faulty GPU driver.

3. Regional Date Formats (Locale.US)

• Source: Android Lint warning SimpleDateFormatWithoutLocale.
• Background: Using SimpleDateFormat without a specific Locale defaults to the user's system language settings. If a user has set their device to a region that uses non-standard date separators or formats, parsing the fixed server strings (YYYY-MM-DD) will fail.
• Fix: Locking the parser to Locale.US in data classes like AuxBatteryData.kt to ensure platform-independent stability.

These points are standard "best practices" that ensure the app remains robust across various manufacturer implementations (Samsung vs. Pixel vs. others).

[dexterbg]

On point 1:

Samsung firmwares in certain regions or older versions may default to other standards (like ISO-8859-1).

That simply cannot be true, as explained above. Let's check the docs again:

https://developer.android.com/reference/java/nio/charset/Charset#defaultCharset()

Android note: The Android platform default is always UTF-8.

It's always UTF-8, with no exceptions.

What is the actual source for the allegation of Samsung diverging from the Android platform specs? Please don't answer with another LLM generated text, give a link to an actual site discussing this.

And btw, if that would be an issue for Samsung devices, it wouldn't be restricted to the 12V history data, and it wouldn't happen to occur only after April 2026 -- Samsung devices are all over the place, and no issues of this kind have been reported before.

On point 2:

Again, why wouldn't that affect all charts on the devices having the issue?

Source: GitHub Issues for the MPAndroidChart library and Android Hardware Acceleration documentation

This is clearly an AI hallucination, there is no mentioning of any Samsung / Exynos / GPU issues in https://github.com/PhilJay/MPAndroidChart, neither in issues nor in pull requests or commits. Same for the Android HW accel docs.

The only place I found discussing this is the PlayCanvas forum, they found an issue initially thought to be Samsung specific, that later turned out to be specific for the Mali G52 chipset. So we should first check if the devices affected have that chipset.

@MylesTwete please check your hardware specs for the GPU chipset used.

On point 3:

That's correct and a valid change.

But it still doesn't apply to the actual issue, as according to Myles there was no region/language change on his devices.