Doorbell client/server

doorbell.py

#!/usr/bin/python3.5

import socket, notify2, time, requests, json, datetime, hashlib, struct

notify2.init("Doorbell")

def notify(summary, text):
    n = notify2.Notification(summary, text)
    n.set_timeout(60)
    n.set_urgency(2)
    n.show()

def receive(hmac):
    data, addr = client.recvfrom(1024)

    if len(data) < 45: return
    magic = data[:2]
    hash = data[3:35]
    full_body = data[36:]
    seq_id = struct.unpack(">Q", full_body[:8])[0]
    body = full_body[9:]

    comp_hash = hashlib.sha256(hmac.encode("utf8") + full_body).digest()
    if comp_hash == hash:
        return seq_id, body.decode("utf8")


client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP) # UDP
client.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
client.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

client.bind(("", 37700))
last_triggered = datetime.datetime(2015,1,1, 1,1,1)
last_seq = 0

while True:
    intensity = 0
    try:
        seq, body = receive("Jeger")
        if last_seq < seq:
            last_seq = seq
            intensity = json.loads(body)["value"]
    except Exception as e:
        print(e)
        pass # todo: not any of this
    if intensity > 100 and (datetime.datetime.now()-last_triggered).seconds > 15:
        print(intensity)
        notify("bell", "The doorbell's ringing, Evelyn.")
        last_triggered = datetime.datetime.now()

heimdallr.py

#!/usr/bin/env python3

import json, time, hashlib, struct, datetime
from socket import *

import board
import busio
import adafruit_veml7700

i2c = busio.I2C(board.SCL, board.SDA)
veml7700 = adafruit_veml7700.VEML7700(i2c)

cs = socket(AF_INET, SOCK_DGRAM)
cs.setsockopt(SOL_SOCKET, SO_REUSEPORT, 1)
cs.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)

def send_message(message, hmac):
        # sequence + message
        message_body   = struct.pack(">Q", int(datetime.datetime.now().timestamp())) + b"\n" + message.encode("utf8")
        # hmac + full message
        message_digest = hashlib.sha256(hmac.encode("utf8") + message_body).digest()
        composed_message = b"DN\n" + message_digest + b"\n" + message_body
        cs.sendto(composed_message, ('<broadcast>', 37700))

while True:
	time.sleep(0.1)
	light = veml7700.lux
	j_ver = json.dumps({"value": light})
	if light>1:
		print(light)
	if light>100:
		send_message(j_ver, "Jeger")