fanD

Daemon for fan controlling like fancontrol

Allows using multiple temperature sources for controlling one fan. It's useful for water cooling systems when cpu and gpu connected in one path

Allows using complex algorithms for compute fan speed (by using JavaScript)

Build and run

cargo build --release
sudo ./target/release/fand

Usage

Usage: fand [OPTIONS]

Options:
  -c, --config <PATH>  [default: /etc/fand/config.toml]
  -h, --help           Print help

Configuration

Configuration read from /etc/fand/config.toml by default

For working needs at least one source.XXX section and at least one fan value

---

main section

Base properties:

• interval update interval in seconds (2 by default)

example:

[main]
interval = 5

---

source file

Reading temperature from file

Properties:

• path path to file for reading. required for file type
• factor multiplier for values from file (0.001 by default)

example:

[source.myCpu]
type = "file"
path = "/sys/devices/platform/nct6775.656/hwmon/hwmon1/temp13_input"

# values in `nct6775` driver written in 'millicelcius' and must be multiplied by 0.001
factor = 0.001

---

source nvidia

Get temperature from nvidia devices. libnvidia-ml.so must be exists in the system

Properties:

• name select card by name. optional
• uuid select card by uuid. optional

You can found name and uuid for all your cards at starting fand with correctly configured nvidia source section

log example:

[2024-02-11T15:05:18Z INFO  fand::source::nvidia] Found NvidiaDevice { name: "NVIDIA GeForce RTX 5000", uuid: "GPU-23eda959-34a7-4abf-8e19-9c0beded366e" }

example:

[source.myGpu]
type = "nvidia"
name = "NVIDIA GeForce RTX 5000"
uuid = "GPU-23eda959-34a7-4abf-8e19-9c0beded366e"

---

fan pwm

Write fan power to file in text format (values in range 0..=255)

Properties:

• path path to pwm file. required for pwm type
• value js code for computing result. required for pwm type

value must return double in range 0.0..=1.0 where 0.0 is power off and 1.0 is full speed

example:

[[fan]]
type = "pwm"
path = "/sys/devices/platform/nct6775.656/hwmon/hwmon2/pwm2"
value = '''
    var calc;
    if (!calc) calc = (minTemp, temp, maxTemp) => Math.min(1, (Math.max(temp, minTemp) - minTemp) / (maxTemp - minTemp) );
    Math.max(1, calc(30, myCpu, 80), calc(30, myGpu, 40)) // result of last line will be used as power
'''