fan.py

#!/usr/bin/env python3
import sys
from types import ModuleType

from i2c_pkg import i2c as i2c_module
from i2c_pkg.emc2301_pkg import emc2301


class RaspiCM4IOBoardFanSensor(emc2301.EMC2301):
    def __init__(self,
                 address: int = 0x2f,
                 busnum: int = 10,
                 i2c: ModuleType = i2c_module,
                 **kwargs):
        super().__init__(address=address,
                         busnum=busnum,
                         i2c=i2c,
                         **kwargs)

    def fan_speed(self) -> int:
        return self.speed()[0]

    def set_fan_speed_percentage(self, percentage: int):
        """Percentage should be 0 - 100"""
        converted_value = int(percentage / 100 * 255)
        self.write_register(register='FAN_SETTING', value=converted_value)


def print_help():
    print(f'Supported commands:')
    print(f'{sys.argv[0]} set (speed in percentage)')
    print(f'{sys.argv[0]} get')


if __name__ == '__main__':
    if len(sys.argv) <= 1:
        print_help()
        sys.exit(1)

    fan = RaspiCM4IOBoardFanSensor()
    if sys.argv[1] == 'set':
        print(f'Setting fan speed to {sys.argv[2]}%')
        try:
            fan.set_fan_speed_percentage(int(sys.argv[2]))
        except ValueError:
            print(f'Incorrect speed percentage value: {sys.argv[2]}')
            sys.exit(1)
        sys.exit(0)

    if sys.argv[1] == 'get':
        print(f'Current fan speed: {fan.fan_speed()} RPM')
        sys.exit(0)

    print(f'Unknown command.')
    print_help()
    sys.exit(1)