mqtt-all.py

#!/usr/bin/env python3
"""
Run mqtt broker on localhost: sudo apt-get install mosquitto mosquitto-clients

Example run: python3 mqtt-all.py --broker 192.168.1.164 --topic enviro --username xxx --password xxxx
"""

import argparse
import ssl
import time

import st7735
from bme280 import BME280
from pms5003 import PMS5003, ReadTimeoutError, SerialTimeoutError

from enviroplus import gas

try:
    # Transitional fix for breaking change in LTR559
    from ltr559 import LTR559

    ltr559 = LTR559()
except ImportError:
    import ltr559

import json
from subprocess import PIPE, Popen, check_output

import paho.mqtt.client as mqtt
from fonts.ttf import RobotoMedium as UserFont
from PIL import Image, ImageDraw, ImageFont

try:
    from smbus2 import SMBus
except ImportError:
    from smbus import SMBus


DEFAULT_MQTT_BROKER_IP = "localhost"
DEFAULT_MQTT_BROKER_PORT = 1883
DEFAULT_MQTT_TOPIC = "enviroplus"
DEFAULT_READ_INTERVAL = 5
DEFAULT_TLS_MODE = False
DEFAULT_USERNAME = None
DEFAULT_PASSWORD = None


# mqtt callbacks
def on_connect(client, userdata, flags, rc):
    if rc == 0:
        print("connected OK")
    else:
        print("Bad connection Returned code=", rc)


def on_publish(client, userdata, mid):
    print("mid: " + str(mid))


# Read values from BME280 and return as dict
def read_bme280(bme280):
    # Compensation factor for temperature
    comp_factor = 2.25
    values = {}
    cpu_temp = get_cpu_temperature()
    raw_temp = bme280.get_temperature()  # float
    comp_temp = raw_temp - ((cpu_temp - raw_temp) / comp_factor)
    values["temperature"] = int(comp_temp)
    values["pressure"] = round(
        int(bme280.get_pressure() * 100), -1
    )  # round to nearest 10
    values["humidity"] = int(bme280.get_humidity())
    data = gas.read_all()
    values["oxidised"] = int(data.oxidising / 1000)
    values["reduced"] = int(data.reducing / 1000)
    values["nh3"] = int(data.nh3 / 1000)
    values["lux"] = int(ltr559.get_lux())
    return values


# Read values PMS5003 and return as dict
def read_pms5003(pms5003):
    values = {}
    try:
        pm_values = pms5003.read()  # int
        values["pm1"] = pm_values.pm_ug_per_m3(1)
        values["pm25"] = pm_values.pm_ug_per_m3(2.5)
        values["pm10"] = pm_values.pm_ug_per_m3(10)
    except ReadTimeoutError:
        pms5003.reset()
        pm_values = pms5003.read()
        values["pm1"] = pm_values.pm_ug_per_m3(1)
        values["pm25"] = pm_values.pm_ug_per_m3(2.5)
        values["pm10"] = pm_values.pm_ug_per_m3(10)
    return values


# Get CPU temperature to use for compensation
def get_cpu_temperature():
    process = Popen(
        ["vcgencmd", "measure_temp"], stdout=PIPE, universal_newlines=True
    )
    output, _error = process.communicate()
    return float(output[output.index("=") + 1:output.rindex("'")])


# Get Raspberry Pi serial number to use as ID
def get_serial_number():
    with open("/proc/cpuinfo", "r") as f:
        for line in f:
            if line[0:6] == "Serial":
                return line.split(":")[1].strip()


# Check for Wi-Fi connection
def check_wifi():
    if check_output(["hostname", "-I"]):
        return True
    else:
        return False


# Display Raspberry Pi serial and Wi-Fi status on LCD
def display_status(disp, mqtt_broker):
    # Width and height to calculate text position
    WIDTH = disp.width
    HEIGHT = disp.height
    # Text settings
    font_size = 12
    font = ImageFont.truetype(UserFont, font_size)

    wifi_status = "connected" if check_wifi() else "disconnected"
    text_colour = (255, 255, 255)
    back_colour = (0, 170, 170) if check_wifi() else (85, 15, 15)
    device_serial_number = get_serial_number()
    message = f"{device_serial_number}\nWi-Fi: {wifi_status}\nmqtt-broker: {mqtt_broker}"
    img = Image.new("RGB", (WIDTH, HEIGHT), color=(0, 0, 0))
    draw = ImageDraw.Draw(img)
    x1, y1, x2, y2 = font.getbbox(message)
    size_x = x2 - x1
    size_y = y2 - y1
    x = (WIDTH - size_x) / 2
    y = (HEIGHT / 2) - (size_y / 2)
    draw.rectangle((0, 0, 160, 80), back_colour)
    draw.text((x, y), message, font=font, fill=text_colour)
    disp.display(img)


def main():
    parser = argparse.ArgumentParser(
        description="Publish enviroplus values over mqtt"
    )
    parser.add_argument(
        "--broker",
        default=DEFAULT_MQTT_BROKER_IP,
        type=str,
        help="mqtt broker IP",
    )
    parser.add_argument(
        "--port",
        default=DEFAULT_MQTT_BROKER_PORT,
        type=int,
        help="mqtt broker port",
    )
    parser.add_argument(
        "--topic", default=DEFAULT_MQTT_TOPIC, type=str, help="mqtt topic"
    )
    parser.add_argument(
        "--interval",
        default=DEFAULT_READ_INTERVAL,
        type=int,
        help="the read interval in seconds",
    )
    parser.add_argument(
        "--tls",
        default=DEFAULT_TLS_MODE,
        action="store_true",
        help="enable TLS"
    )
    parser.add_argument(
        "--username",
        default=DEFAULT_USERNAME,
        type=str,
        help="mqtt username"
    )
    parser.add_argument(
        "--password",
        default=DEFAULT_PASSWORD,
        type=str,
        help="mqtt password"
    )
    args = parser.parse_args()

    # Raspberry Pi ID
    device_serial_number = get_serial_number()
    device_id = "raspi-" + device_serial_number

    print(
        f"""mqtt-all.py - Reads Enviro plus data and sends over mqtt.

    broker: {args.broker}
    client_id: {device_id}
    port: {args.port}
    topic: {args.topic}
    tls: {args.tls}
    username: {args.username}
    password: {args.password}

    Press Ctrl+C to exit!

    """
    )

    mqtt_client = mqtt.Client(client_id=device_id)
    if args.username and args.password:
        mqtt_client.username_pw_set(args.username, args.password)
    mqtt_client.on_connect = on_connect
    mqtt_client.on_publish = on_publish

    if args.tls is True:
        mqtt_client.tls_set(tls_version=ssl.PROTOCOL_TLSv1_2)

    if args.username is not None:
        mqtt_client.username_pw_set(args.username, password=args.password)

    mqtt_client.connect(args.broker, port=args.port)

    bus = SMBus(1)

    # Create BME280 instance
    bme280 = BME280(i2c_dev=bus)

    # Create LCD instance
    disp = st7735.ST7735(
        port=0,
        cs=1,
        dc="GPIO9",
        backlight="GPIO12",
        rotation=270,
        spi_speed_hz=10000000
    )

    # Initialize display
    disp.begin()

    # Try to create PMS5003 instance
    HAS_PMS = False
    try:
        pms5003 = PMS5003()
        _ = pms5003.read()
        HAS_PMS = True
        print("PMS5003 sensor is connected")
    except SerialTimeoutError:
        print("No PMS5003 sensor connected")

    # Display Raspberry Pi serial and Wi-Fi status
    print(f"RPi serial: {device_serial_number}")
    wifi_status = "connected" if check_wifi() else "disconnected"
    print(f"Wi-Fi: {wifi_status}\n")
    print(f"MQTT broker IP: {args.broker}")

    # Set an initial update time
    update_time = time.time()

    # Main loop to read data, display, and send over mqtt
    mqtt_client.loop_start()
    while True:
        try:
            values = read_bme280(bme280)
            if HAS_PMS:
                pms_values = read_pms5003(pms5003)
                values.update(pms_values)
            time_since_update = time.time() - update_time
            if time_since_update >= args.interval:
                update_time = time.time()
                values["serial"] = device_serial_number
                print(values)
                mqtt_client.publish(args.topic, json.dumps(values), retain=True)
                display_status(disp, args.broker)
        except Exception as e:
            print(e)


if __name__ == "__main__":
    main()