Python script that allows monitoring sensors value changes over time. Help to detect sensors on macOS. Requires colorama python package and Stats that contains SMC tool.

watch-smc.py

#!/usr/bin/env python3

# Usage:
# (while true; do /Applications/Stats.app/Contents/Resources/smc list -t; sleep 1; done) | python3 watch-smc.py

from colorama import Fore, Back, Style
import time
import fileinput
import re

keys = {}
orig = {}
recent = {}
names = {}

pwr_re = re.compile(r'\[([A-Za-z0-9 ]{4})\]\s+([0-9.]+)')
start = time.time()

def name_fmt(key):
    return names.get(key, "")

def delta_fmt(delta, color_thresh, bright_thresh, prefix):
    abs_delta = abs(delta)
    color = ""
    if abs_delta > color_thresh:
        color = Fore.RED if delta > 0.0 else Fore.GREEN
        color += Style.BRIGHT if abs_delta > 10.0 else ""
    return color + f"{prefix}{delta:+8.3f}" + Style.RESET_ALL

for line in fileinput.input():
    line = line.strip()

    # Empty line, which corresponds to the second line for an "smc list" read.
    # Used to identify the start of a new sensor read cycle.
    if not line:
        print(f"{time.time() - start:7.3f}")
        continue

    if line[0] != '[':
        continue

    m = pwr_re.match(line)
    if not m:
        continue
    key, value = m.groups()
    value = float(value)

    if key not in keys:
        # First read, store values.
        keys[key] = value
        orig[key] = value
        continue

    # Delta since start of run.
    basedelta = value - orig[key]

    # Delta since last read.
    delta = value - keys[key]

    # Store new value.
    keys[key] = value

    abs_delta = abs(delta)
    abs_basedelta = abs(basedelta)
    color = Style.RESET_ALL

    if abs_basedelta > 7.0:
        recent[key] = 1

    if abs_delta > 3.0:
        recent[key] = 2
        print(f"{key}: {value:7.3f}   {delta_fmt(delta, 3.0, 10.0, 'L')} {delta_fmt(basedelta, 3.0, 10.0, 'B')} {name_fmt(key)}" + Style.RESET_ALL)
    elif key in recent:
        if recent[key] > 0:
            recent[key] -= 1
            print(f"{key}: {value:7.3f}   {delta_fmt(delta, 3.0, 10.0, 'L')} {delta_fmt(basedelta, 3.0, 10.0, 'B')} {name_fmt(key)}" + Style.RESET_ALL)
        else:
            del recent[key]