edit of `pi_temp_mon.py` which uses a single serial channel to communicate with an arduino running the `serial_colors.ino` sketch i previously published

pi_arduino_tempmon.py

import click
import serial
import time
import subprocess
import re

@click.command()
@click.option('--brightness', default=50, prompt='Enter brightness', 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)
@click.option('--serial_port', default='/dev/ttyS0', prompt='Enter serial port', type=str)
def main(brightness, temp_floor, temp_ceiling, serial_port):
    ser = serial.Serial(serial_port, 9600)

    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 = (255, 0, 0)  # Red
            else:
                ratio = (temp - temp_floor) / (temp_ceiling - temp_floor)
                color = (int(ratio * 255), int((1 - ratio) * 255), 0)

            color = tuple(max(0, min(int(c * brightness / 100), 255)) for c in color)

            ser.write(bytearray(color))

            time.sleep(1)
    except KeyboardInterrupt:
        pass
    finally:
        ser.close()

if __name__ == '__main__':
    main()