class Alarm:
gas_threshold = 1000
smoke_threshold = 2000
temperature_threshold = 55
def __init__(self):
self.fire_detected = False
self.buzzer = Buzzer()
self.adc = MCP3008()
async def connect_azure(self):
conn_str = "HostName=Smartfire.azure-devices.net;DeviceId=smartfire-1;SharedAccessKey=sFQIzn79jON2ZBpL3iiBHScmIBXMXf57bA5PFM69ie8="
self.device_client = IoTHubDeviceClient.create_from_connection_string(
conn_str)
await self.device_client.connect()
async def start(self):
await self.connect_azure()
await self.start_alarm()
async def start_alarm(self):
while True:
humidity, temperature = self.get_dht11_data()
mq3_data = self.get_mq3_data()
mq9_data = self.get_mq9_data()
await self.save_measurements(temperature, humidity, mq3_data,
mq9_data)
sleep(4)
if ((mq3_data > Alarm.gas_threshold
or mq9_data > Alarm.smoke_threshold
or temperature > Alarm.temperature_threshold)
and not self.fire_detected):
self.fire_detected = True
self.buzzer.start()
else:
self.fire_detected = False
self.buzzer.stop()
async def save_measurements(self, temperature, humidity, mq3_data,
mq9_data):
print("saving saving measurements")
gas_percentage = self.convert_percentage(mq3_data, 350, 1000)
co_percentage = self.convert_percentage(mq3_data, 990, 5000)
data = {
'device_id': 1,
'event': "measurement",
'temperature': float(temperature),
'gas_percentage': gas_percentage,
'co_percentage': co_percentage,
'is_fire': 1 if self.fire_detected else 0,
'humidity': float(humidity)
}
json_body = json.dumps(data)
await self.device_client.send_message(json_body)
twin = await self.device_client.get_twin()
self.handle_twin(twin)
await self.device_client.disconnect()
def handle_twin(self, twin):
if (not self.fire_detected):
if ('desired' in twin):
desired = twin['desired']
if ('is_fire' in desired):
if desired['is_fire'] == 1:
self.buzzer.start()
elif desired['is_fire'] == 0:
self.buzzer.stop()
def convert_percentage(self, number, min, max):
percentage = round(((number - min) / (max - min)) * 100, 2)
if percentage > 100:
percentage = 100
elif percentage < 0:
percentage = 0
return float(percentage)
def get_dht11_data(self):
return Adafruit_DHT.read_retry(11, 4)
def get_mq3_data(self):
return self.adc.read(0)
def get_mq9_data(self):
return self.adc.read(1)
