a silly little raspberry pi rgb led temperature monitor script. not optimized at all, will rewrite in c as soon as i care enough.

pi_temp_mon.py

import click, RPi.GPIO as GPIO, time, subprocess, re

@click.command()
@click.option('--brightness', default=50, prompt='Enter brightness', type=int)
@click.option('--r_pin', default=32, prompt='Enter R pin', type=int)
@click.option('--g_pin', default=33, prompt='Enter G pin', type=int)
@click.option('--b_pin', default=12, prompt='Enter B pin', type=int)
@click.option('--temp_floor', default=40.0, prompt='Enter temperature floor', type=float)
@click.option('--temp_ceiling', default=80.0, prompt='Enter temperature ceiling', type=float)
def main(brightness, r_pin, g_pin, b_pin, temp_floor, temp_ceiling):
    GPIO.setmode(GPIO.BOARD)
    GPIO.setwarnings(False)
    pins = [r_pin, g_pin, b_pin]
    GPIO.setup(pins, GPIO.OUT)
    rp, gp, bp = (GPIO.PWM(pin, 100) for pin in pins)
    [pwm.start(0) for pwm in (rp, gp, bp)]

    try:
        while True:
            temp = float(re.search(r'temp=([\d\.]+)', subprocess.run(['vcgencmd', 'measure_temp'], capture_output=True).stdout.decode()).group(1))
            if temp > temp_ceiling:
                color = (100, 0, 0)
            else:
                ratio = (temp - temp_floor) / (temp_ceiling - temp_floor)
                color = (ratio * 100, (1 - ratio) * 100, 0)
            [pwm.ChangeDutyCycle(max(0, min(c * brightness / 100, 100))) for pwm, c in zip((rp, gp, bp), color)]
            time.sleep(1)
    except KeyboardInterrupt: pass
    finally:
        [pwm.stop() for pwm in (rp, gp, bp)]
        GPIO.cleanup()

if __name__ == '__main__':
    main()