Script to be used in my Raspberry Pi 4 cluster to show information about CPU Load, Ram Load and CPU Temperature.

cluster-leds.py

#!/usr/bin/env python3

"""
=============== DISCLAIMER ===================
The original library (blinkt) belongs to Pimoroni Company.
https://github.com/pimoroni/blinkt.

I just adapted some examples to meet my needs.

=============== END DISCLAIMER ===============


This script is to show the following information (in order)

- RAM Load
- CPU Load
- CPU Temperature

Colours used:
rgb(115, 0, 230) # RAM Load: Electric indigo
rgb(0, 115, 230) # CPU Load: True Blue
rgb(230, 115, 0) # CPU Temperture: Fulvous

"""

import time
import blinkt
from datetime import datetime, timedelta
from subprocess import PIPE, Popen
from sys import exit

try:
    import psutil
except ImportError:
    exit("This script requires the psutil module\nInstall with: pip3 install psutil")

blinkt.set_clear_on_exit()
blinkt.set_brightness(0.1)

def show_graph(v, r, g, b):
    v *= blinkt.NUM_PIXELS
    
    # I use reversed version because of the way I have the leds set (physically)
    for x in reversed(range(blinkt.NUM_PIXELS)):
        if v < 0:
            r, g, b = 0, 0, 0
        else:
            r, g, b = [int(min(v, 1.0) * c) for c in [r, g, b]]

        blinkt.set_pixel(x, r, g, b)
        v -= 1

    blinkt.show()


def get_ram_load():
    return psutil.virtual_memory().percent


def get_cpu_temperature():
    process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE)
    output, _error = process.communicate()
    output = output.decode()

    pos_start = output.index('=') + 1
    pos_end = output.rindex("'")

    temp = float(output[pos_start:pos_end])

    return temp


def show_info(resource, seconds = 5):
    '''
    Shows the desired information about the given resource
    for the given time in seconds (default to five secs).
    
    Parameters:
        resource (str): Resource you want to get the information. cpu_load | cpu_temp | ram_load
        seconds (int): Amount of seconds tu want to see the information shown by the leds. Default = 5 seconds.
    '''
    now = datetime.now()
    later = now + timedelta(seconds=seconds)

    while now < later:
        v = fns_dispatcher[resource]() / 100.0
        show_graph(v, *colours[resource])

        time.sleep(0.01)
        now = datetime.now()


colours = {
    'cpu_load': [0, 115, 230],
    'cpu_temp': [230, 115, 0],
    'ram_load': [115, 0, 230]
}

fns_dispatcher = {
    'cpu_load': psutil.cpu_percent,
    'cpu_temp': get_cpu_temperature,
    'ram_load': get_ram_load
}

while True:
    show_info('ram_load')
    show_info('cpu_load')
    show_info('cpu_temp')