blinky-py/blinky.py

#!/usr/bin/python3

from pixels import TermLEDs
import board
import neopixel
import json
import os
import time

import pyinotify, threading
import paho.mqtt.subscribe as subscribe

from pattern import Pattern


lock_reload = threading.Lock()
cond_reload = threading.Condition(lock_reload)
reload = False
config = None


# Monitor config from file

config_file = "blinky.json"

def file_thread(file):
    class EventHandler(pyinotify.ProcessEvent):
        def process_IN_CLOSE_WRITE(self, event):
            global reload, config
            with lock_reload:
                print("Triggering file reload")
                config = None
                reload = True
                cond_reload.notify_all()

    wm = pyinotify.WatchManager()
    notifier = pyinotify.Notifier(wm, EventHandler())
    wdd = wm.add_watch(file, pyinotify.IN_CLOSE_WRITE)

    notifier.loop()

threading.Thread(target=file_thread, args=[config_file]).start()


# Monitor config from MQTT

class mqtt:
    topic = "blinky/config"
    hostname = "mqtt.jrhoffa.com"
    auth = {'username':"blinky", 'password':"rainbow"}
    tls = {'ca_certs':"/etc/ssl/certs/ca-certificates.crt"}

def mqtt_thread():
    def on_message(client, userdata, message):
        global reload, config
        with lock_reload:
            print("Triggering MQTT reload")
            try:
                config = json.loads(message.payload)
                reload = True
                cond_reload.notify_all()
            except:
                print("Invalid MQTT config")

    subscribe.callback(on_message, mqtt.topic, hostname=mqtt.hostname, auth=mqtt.auth, port=8883, tls=mqtt.tls)

threading.Thread(target=mqtt_thread).start()


### Entry Point ##

framerate = 30

length = None
patterns = None
pixels = None

with lock_reload:
    while True:
        print("Loading config")
        reload = False

        try:
            config = config or json.load(open(config_file))

            new_length = config['length']

            if length != new_length:
                print("New string config")
                length = new_length
                pixels = neopixel.NeoPixel(board.D18, length, pixel_order=neopixel.RGB, auto_write=False)
                #pixels = TermLEDs(length)

            patterns = [(pattern['length'], Pattern.from_dict(pattern)) for pattern in config['patterns']]

        except Exception as e:
            print("Failed to load config:", e)

        if not pixels or not patterns:
            print("Waiting for valid config")
            while not reload:
                cond_reload.wait()
        else:
            target = time.time()
            while not reload:
                lock_reload.release()

                # Generate and show new light pattern
                pixels[:] = [x for y in (pattern.step(length) for (length, pattern) in patterns) for x in y]
                pixels.show()

                # Go ahead and sleep, maintaining maximum framerate
                target += (1 / framerate)
                now = time.time()
                if target > now:
                    time.sleep(target - now)

                lock_reload.acquire()