FanControl.AcerPredatorPH315

A FanControl plugin that adds native fan control for the Acer Predator Helios 300 (PH315-53) by talking to the Embedded Controller through PawnIO.

The register map was transcribed from Arghadip Deb's NBFC config ("Acer Predator PH315-53.xml") and cross-checked against LokeshP13/only-laptop-fans.

⚠️ Writing the wrong byte to the wrong EC register can brick fans or melt your laptop. Use at your own risk. Before attaching a curve, manually validate Set(0) and Set(100) on a cool system.

What it exposes

Sensor	Kind	EC reg (dec / hex)
CPU fan speed	IPluginSensor	19 / 0x13 (word, raw 0–6122)
GPU fan speed	IPluginSensor	21 / 0x15 (word, raw 0–6122)
CPU fan control 0–100	IPluginControlSensor2	55 / 0x37
GPU fan control 0–100	IPluginControlSensor2	58 / 0x3A

The "fan speed" reading is the raw EC word, which NBFC calibrates against MaxSpeedValueRead = 6122. It is not a true tachometer reading — treat it as a 0..6122 scalar that tracks the real fan well enough to drive a graph (idle ≈ 0, full tilt ≈ 5000–6000). FanControl labels it as RPM in the UI regardless.

PairedFanSensorId on the two control sensors lets FanControl auto-bind each slider to the matching speed readout.

Init / reset writes

Initialize() flips the EC into manual-fan mode and silences CoolBoost. Close() restores the BIOS-managed values.

Purpose	Reg	On-init value	Reset value
CPU manual mode	34	12	4
GPU manual mode	33	48	16
CoolBoost off	16	0	1

Install

1. Install FanControl V238 or newer. This version ships PawnIO and registers its kernel driver. Verify C:\Program Files\PawnIO\PawnIOLib.dll exists.
2. In FanControl, open Settings → Plugins and install FanControl.AcerPredatorPH315.dll from there.
3. Restart FanControl. Two new fan speed sensors and two control sliders should appear under Acer Predator PH315-53.

If the plugin fails to initialize, FanControl swallows the exception. See Diagnostics for where to look.

Build

1. Copy FanControl.Plugins.dll from your FanControl install dir into ./lib/.
2. Download LpcACPIEC.bin from namazso/PawnIO.Modules releases and drop it into ./modules/.
3. dotnet build FanControl.AcerPredatorPH315.sln -c Release

The project multi-targets netstandard2.0 and net10.0-windows:

• bin/Release/netstandard2.0/FanControl.AcerPredatorPH315.dll — loads into either the .NET 8 or _net_10_0 FanControl installer.
• bin/Release/net10.0-windows/FanControl.AcerPredatorPH315.dll — only the _net_10_0 installer.

If you don't care about portability, the net10.0-windows DLL matches a current FanControl install.

The solution contains the multi-targeted plugin project and a separate AcerProbe console utility. There is no wrapper build project; a normal solution build produces both plugin target-framework outputs directly.

Probe utility

Probe/FanControl.AcerPredatorPH315.Probe.csproj builds AcerProbe, a standalone administrator console tool for exploring the Acer gaming WMI surface without loading the FanControl plugin. It does not use PawnIO or touch the EC directly.

Example:

dotnet run --project Probe/FanControl.AcerPredatorPH315.Probe.csproj -- enum

Known issues

• Fan speed reads occasionally fail. The ACPI driver and this plugin both arbitrate for the EC; when ACPI wins, the read times out. The sensor holds its last good value instead of dropping to zero so the graph stays smooth.
• Fans don't return to BIOS auto on a hard crash. Close() writes the reset values, but a FanControl crash skips that. The EC's own thermal trip still protects the CPU; if you see a stuck low duty after a crash, reboot.

Diagnostics

FanControl silently catches plugin Initialize() exceptions and surfaces them only as "Acer Predator PH315-53 could not initialize or has no sensors". The plugin therefore writes its own log next to the DLL:

<plugin folder>\FanControl.AcerPredatorPH315.log

Check that file first whenever the plugin behaves oddly.

Layout

FanControl.AcerPredatorPH315.sln      # plugin + probe solution
FanControl.AcerPredatorPH315.csproj   # multi-target plugin project
AcerPredatorPlugin.cs                 # IPlugin2 entrypoint
Diagnostics/PluginLog.cs              # file logger (FanControl swallows init exceptions)
Ec/AcerEc.cs                          # EC handshake over 0x62/0x66
Ec/PredatorRegisters.cs               # register map (NBFC xml + only-laptop-fans)
PawnIO/PawnIONative.cs                # P/Invoke -> PawnIOLib.dll
PawnIO/PawnIOLibLoader.cs             # locates PawnIOLib.dll outside PATH and LoadLibrary's it
PawnIO/PawnIOSession.cs               # RAII handle + module loader
Sensors/PredatorFanSpeedSensor.cs     # IPluginSensor (read)
Sensors/PredatorFanControlSensor.cs   # IPluginControlSensor2 (write, paired)
Probe/                                # standalone WMI probe utility
modules/LpcACPIEC.bin                 # embedded PawnIO module (you supply)
lib/FanControl.Plugins.dll            # plugin SDK (you supply)

Author

Built by Samuel Johansson (@phaax) — Phaax Games.

Credits

• Rem0o/FanControl.Releases — the host application and plugin SDK.
• namazso/PawnIO and namazso/PawnIO.Modules — the signed kernel driver and LpcACPIEC module that make EC access possible without a custom driver.
• Arghadip Deb's NBFC config for the PH315-53 register map.
• LokeshP13/only-laptop-fans — independent Python implementation used to cross-check register semantics.