From d6fa78ae5f5b1fb9e0b590bfe35b4a02c16de935 Mon Sep 17 00:00:00 2001
From: BlackMark <me@blackmark.me>
Date: Wed, 1 Apr 2020 05:07:30 +0200
Subject: [PATCH] Change temperature curve to cubic

---
 fantemp/controller.cpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/fantemp/controller.cpp b/fantemp/controller.cpp
index 5f3c931..06977d8 100644
--- a/fantemp/controller.cpp
+++ b/fantemp/controller.cpp
@@ -24,7 +24,14 @@ void Controller::callback()
 
 uint8_t Controller::mapTemperature(double temperature)
 {
-	double fanSpeed = (10 * temperature - 200) / 3;
+	[[maybe_unused]] constexpr auto linearCurve = [](double x) { return (10 * x - 200) / 3; };
+	constexpr auto cubicCurve = [](double x) {
+		if (x < 20)
+			return 0.0;
+		return 0.002246 * x * x * x - 0.09 * x * x + 0.91 * x;
+	};
+
+	double fanSpeed = cubicCurve(temperature);
 	return clamp<uint8_t>(fanSpeed, 0, 100);
 }