PiMoroni Fan Shim on LibreElec (including the LEDs)

fanshim.py

#!/usr/bin/env python
#
# place command below in /storage/.config/autostart.sh
#   nohup /storage/fanshim.py &
#
# By Maxime Vincent (maxime [dot] vince [at] gmail [dot] com)
#
# Based on:
# http://www.philrandal.co.uk/blog/archives/2019/07/entry_214.html 
# https://forum-raspberrypi.de/forum/thread/43568-fan-shim-steuern/
# and:
# https://github.com/pimoroni/fanshim-python/blob/master/examples/automatic.py
#
import atexit
import colorsys
import argparse
import time
import sys
import subprocess

sys.path.append('/storage/.kodi/addons/virtual.rpi-tools/lib')
import RPi.GPIO as GPIO

FAN = 18
DAT = 15
CLK = 14
PIXELS_PER_LIGHT = 4
DEFAULT_BRIGHTNESS = 3
MAX_BRIGHTNESS = 3

pixels = [[0, 0, 0, DEFAULT_BRIGHTNESS]] * PIXELS_PER_LIGHT
fan_enabled = False

parser = argparse.ArgumentParser()
parser.add_argument('--off-threshold', type=float, default=55.0, help='Temperature threshold in degrees C to enable fan')
parser.add_argument('--on-threshold', type=float, default=65.0, help='Temperature threshold in degrees C to disable fan')
parser.add_argument('--delay', type=float, default=2.0, help='Delay, in seconds, between temperature readings')
parser.add_argument('--verbose', action='store_true', default=False, help='Output temp and fan status messages')
parser.add_argument('--noled', action='store_true', default=False, help='Disable LED control')
parser.add_argument('--brightness', type=float, default=255.0, help='LED brightness, from 0 to 255')

args = parser.parse_args()

def init():
    # For FAN
    GPIO.setwarnings(False)
    GPIO.setmode(GPIO.BCM)
    GPIO.setup(FAN, GPIO.OUT)
    # For LED
    GPIO.setup(DAT, GPIO.OUT)
    GPIO.setup(CLK, GPIO.OUT)
    atexit.register(_exit)
    set_light(0, 0, 0)
    return()

def set_pixel(x, r, g, b, brightness=None):
    """Set the RGB value, and optionally brightness, of a single pixel.

    If you don't supply a brightness value, the last value will be kept.

    :param x: The horizontal position of the pixel: 0 to 7
    :param r: Amount of red: 0 to 255
    :param g: Amount of green: 0 to 255
    :param b: Amount of blue: 0 to 255
    :param brightness: Brightness: 0.0 to 1.0 (default around 0.2)

    """
    if brightness is None:
        brightness = pixels[x][3]
    else:
        brightness = int(float(MAX_BRIGHTNESS) * brightness) & 0b11111

    pixels[x] = [int(r) & 0xff, int(g) & 0xff, int(b) & 0xff, brightness]


def set_light(r, g, b):
    """Set the RGB colour of an individual light in your Plasma chain.

    This will set all four LEDs on the Plasma light to the same colour.

    :param r: Amount of red: 0 to 255
    :param g: Amount of green: 0 to 255
    :param b: Amount of blue: 0 to 255

    """
    for x in range(4):
        set_pixel(x, r, g, b)

    """Output the buffer """
    _sof()

    for pixel in pixels:
        r, g, b, brightness = pixel
        _write_byte(0b11100000 | brightness)
        _write_byte(b)
        _write_byte(g)
        _write_byte(r)

    _eof()


# Emit exactly enough clock pulses to latch the small dark die APA102s which are weird
# for some reason it takes 36 clocks, the other IC takes just 4 (number of pixels/2)
def _eof():
    GPIO.output(DAT, 0)
    for x in range(36):
        GPIO.output(CLK, 1)
        time.sleep(0.0000005)
        GPIO.output(CLK, 0)
        time.sleep(0.0000005)

def _sof():
    GPIO.output(DAT, 0)
    for x in range(32):
        GPIO.output(CLK, 1)
        time.sleep(0.0000005)
        GPIO.output(CLK, 0)
        time.sleep(0.0000005)

def _write_byte(byte):
    for x in range(8):
        GPIO.output(DAT, byte & 0b10000000)
        GPIO.output(CLK, 1)
        time.sleep(0.0000005)
        byte <<= 1
        GPIO.output(CLK, 0)
        time.sleep(0.0000005)

def _exit():
    set_light(0, 0, 0)
    GPIO.cleanup()

def set_fan(status):
    global fan_enabled
    changed = False
    if status != fan_enabled:
        changed = True
	GPIO.output(FAN, status)
    fan_enabled = status
    return changed
    
def watch_temp():
    global fan_enabled
    cpu_temp = get_cpu_temp()
    if fan_enabled == False and cpu_temp >= args.on_threshold:
	print("Enabling fan!")
        set_fan(True)
    if fan_enabled == True and cpu_temp <= args.off_threshold:
	print("Disabling fan!")
        set_fan(False)
    return();

def get_cpu_temp():
    return float(subprocess.check_output(['vcgencmd', 'measure_temp'])[5:-3])

def get_cpu_freq():
    return float(subprocess.check_output(['vcgencmd', 'measure_clock', 'arm'])[14:-1])/1000000

def update_led_temperature(temp):
    temp -= args.off_threshold
    temp /= float(args.on_threshold - args.off_threshold)
    temp = max(0, min(1, temp))
    temp = 1.0 - temp
    temp *= 120.0
    temp /= 360.0
    r, g, b = [int(c * 255.0) for c in colorsys.hsv_to_rgb(temp, 1.0, args.brightness / 255.0)]
    set_light(r, g, b)

try:
    init() 
    while True:
        t = get_cpu_temp()
        f = get_cpu_freq()

        if args.verbose:
            print("Current: {:05.02f} Target: {:05.02f} Freq {: 5.02f} On: {}".format(t, args.off_threshold, f, fan_enabled))

        watch_temp()

        if not args.noled:
            update_led_temperature(t)

        time.sleep(args.delay)

except KeyboardInterrupt:
    pass