RPM Status LEDs

Purpose

The RPM Status LEDs module provides visual RPM feedback using the per-fan RGB LEDs on Rev 3.x boards. Each LED sweeps through a full HSV hue rotation from red (0 RPM) through orange, yellow, and chartreuse to green (full RPM), giving at-a-glance fan health status without checking Home Assistant.

When to Use

Use this module when you want a quick visual indicator of whether your fans are running and at what relative speed. It pairs with any temperature module — the temperature module controls the fan speed, and the LEDs show you the result.

See the modules overview for a comparison of all available modules.

Configuration

Variable	Default	Description
`full_rpm`	`"2500"`	RPM value that maps to fully green LED
`brightness`	`"0.5"`	LED brightness 0.0–1.0
`update_interval`	`"1s"`	LED update frequency
`fan1_led_enabled`	`"true"`	Enable Fan 1 LED
`fan2_led_enabled`	`"true"`	Enable Fan 2 LED
`fan3_led_enabled`	`"true"`	Enable Fan 3 LED
`fan4_led_enabled`	`"true"`	Enable Fan 4 LED

How It Works

The module reads the RPM sensor for each enabled fan at the configured update_interval (default: every second) and maps the value to a red-to-green HSV hue rotation:

0 RPM — fully red (hue 0°)
25% of full_rpm — orange (hue 30°)
50% of full_rpm — yellow (hue 60°)
75% of full_rpm — chartreuse (hue 90°)
full_rpm or above — fully green (hue 120°)

Because the HSV rotation always keeps at least one RGB channel at full output, the LED stays vivid at every point in the range — unlike a linear red/green crossfade which dims to half brightness at midpoint.

LED brightness is configurable via the brightness variable. The module writes directly to the fan1_led through fan4_led partition light entities defined in the Rev 3.x hardware packages. Individual LEDs can be disabled via the fanX_led_enabled variables, leaving those LEDs free for other uses.

Home Assistant Entities

This module creates no additional Home Assistant entities. It writes directly to the existing LED partition light entities (fan1_led through fan4_led) that are already exposed by the Rev 3.x hardware package.

YAML Examples

Basic Usage

packages:
  rpm_status_leds:
    url: https://github.com/zeroflow/wifi-fancontroller
    ref: main
    files:
      - path: modules/rpm_status_leds.yaml
        vars:
          full_rpm: "2500"

Dimmed LEDs with Unused Channels Disabled

packages:
  rpm_status_leds:
    url: https://github.com/zeroflow/wifi-fancontroller
    ref: main
    files:
      - path: modules/rpm_status_leds.yaml
        vars:
          full_rpm: "2500"
          brightness: "0.2"
          fan3_led_enabled: "false"
          fan4_led_enabled: "false"

Slower Update Rate

Reduce the update frequency to save resources if rapid LED changes aren’t needed:

packages:
  rpm_status_leds:
    url: https://github.com/zeroflow/wifi-fancontroller
    ref: main
    files:
      - path: modules/rpm_status_leds.yaml
        vars:
          update_interval: "5s"

Quieter Fans

For fans with a lower maximum RPM, set full_rpm to match so the color gradient scales correctly:

packages:
  rpm_status_leds:
    url: https://github.com/zeroflow/wifi-fancontroller
    ref: main
    files:
      - path: modules/rpm_status_leds.yaml
        vars:
          full_rpm: "1500"

Tuning Tips

Set full_rpm to your fans’ actual maximum RPM for accurate color representation. Check the fan datasheet or observe the maximum RPM reading in Home Assistant with fans set to 100% speed.
If LEDs always show green, your full_rpm value is set too low — the fans are exceeding it. Increase full_rpm to match the actual top speed.
If LEDs always show red or orange, your full_rpm may be set too high, or the fans are running slowly. Check that the fans are receiving adequate power and that the PWM signal is set above 0%.
Reduce brightness in dark environments to avoid glare. Values around 0.1-0.2 work well for enclosed spaces.