From 2552b274b173a774a2bcf53162adf3443a9aa334 Mon Sep 17 00:00:00 2001 From: Andrew Scheller Date: Tue, 17 Jun 2025 14:23:59 +0100 Subject: [PATCH] Add note about adjusting Pi5 fan speeds --- .../asciidoc/computers/raspberry-pi/frequency-management.adoc | 2 ++ 1 file changed, 2 insertions(+) diff --git a/documentation/asciidoc/computers/raspberry-pi/frequency-management.adoc b/documentation/asciidoc/computers/raspberry-pi/frequency-management.adoc index cb57b7099e..d8baf8c40a 100644 --- a/documentation/asciidoc/computers/raspberry-pi/frequency-management.adoc +++ b/documentation/asciidoc/computers/raspberry-pi/frequency-management.adoc @@ -84,6 +84,8 @@ As the temperature of the Raspberry Pi 5 increases, the fan reacts in the follow Temperature decreases use the same mapping with a 5°C **hysteresis**; fan speed decreases when the temperature drops to 5°C below each of the above thresholds. +NOTE: The temperature, hysteresis and speed figures given above can be adjusted by using the various `fan_tempN`, `fan_tempN_hyst` and `fan_tempN_speed` dtoverlay settings (where `N` is 0, 1, 2 or 3). See https://github.com/raspberrypi/linux/blob/rpi-6.12.y/arch/arm/boot/dts/overlays/README[the overlays README] for full details. For example, adding `dtparam=fan_temp0=55000` to `/boot/firmware/config.txt` will cause the fan to remain off until the Raspberry Pi 5's temperature reaches 55°C. + At boot the fan is turned on, and the tachometer input is checked to see if the fan is spinning. If it is, then the `cooling_fan` device tree overlay is enabled. This overlay is in `bcm2712-rpi-5-b.dtb` by default, but with `status=disabled`. ==== Raspberry Pi 5 fan connector pinout