Add Temperature Offset option in dietpi-config

[MPPzzz]

Proposing a new feature

In the recent dietpi-config update, we can now manually select the CPU temperature source. This is a great addition!

However, for some SBCs like the Orange Pi Zero (Allwinner H2+/H3), the thermal sensor reporting is notoriously inaccurate due to hardware/kernel calibration issues (e.g., showing 10-12°C when the actual temp is around 40°C).

Currently, the only way to fix this is by running a background script to read the raw value, add an offset, and write it to a temporary file (e.g., in /dev/shm/), then pointing dietpi-config to that file.

Proposed Solution

It would be much cleaner if dietpi-config (or the underlying monitoring script) included an "Offset" field.

• Users could input a value (e.g., +30 or -5) in Celsius.
• DietPi would then apply this offset to the value read from the selected sensor before displaying it in the banner, htop, or other DietPi tools.

Context

• Device: Orange Pi Zero LTS (Allwinner H2+)
• Kernel: 6.12.58-current-sunxi
• Problem: Raw value from /sys/class/thermal/thermal_zone0/temp is consistently ~30,000 m°C lower than reality.

[MichaIng]

This sounds more like something to fix in the kernel. A negative offset has quite some critical implications, like thermal throttling and emergency shutdowns happen too late 🤔. Also, how do you know the offset? Even with a good thermometer held directly onto the chip, it will show a too low one, and exact offset will be some rough guess at best.

[MPPzzz]

Thanks for the quick response and the detailed explanation!

I completely agree that this is a kernel/calibration issue inherent to the sunxi (Allwinner H2+/H3) chips and that changing the raw value could interfere with critical thermal safety mechanisms.

The main motivation for this request is purely for monitoring/UI purposes. Seeing "11°C" on the DietPi banner or htop while the ambient temperature is 30°C makes the built-in monitoring tools feel "broken" for many sunxi users.

Regarding the offset accuracy, you are right; it is a "rough guess." Most users in the Armbian/sunxi community have found that an offset of +20°C to +30°C brings the readings into a realistic range compared to other similar SBCs.

Proposed middle ground:
Could we have a "Display-only Offset" that only affects the DietPi-Banner and internal scripts, without touching any kernel parameters or system-wide thermal files? This would fix the UI inconsistency while keeping the kernel's safety features intact (even if they are currently based on inaccurate raw data).

If this is still too risky or outside the scope of DietPi, I understand! I'll stick to my custom background script workaround.

[MichaIng]

I made a feature request from this. Wouldn't be hard to implement. My main concern is the added number of command calls and disk reads to our CPU temperature function, after we increased it just last release, for an issue which really shouldn't exist for other than just visual reasons. And at least I didn't observe this issue on my Allwinner H3 NanoPi M1, while we do not officially support the Orange Pi Zero.

[MPPzzz]

Understood, and thanks for the insight! I completely respect the decision to prioritize performance and keep the temperature function lean, especially since this is a visual inconsistency on a non-officially supported board.

It's interesting that your NanoPi M1 doesn't show this—it really highlights how "hit or miss" the factory calibration on these Orange Pi Zero units can be.

Since it's already tagged as a feature request, I'm happy to leave it there for whenever it makes sense to implement (perhaps as an optional, low-priority toggle). In the meantime, I'll continue using my manual workaround to keep things tidy on my end.

Thanks again for maintaining such a great project!