MQTTsensord

Python daemon transmitting local sensor updates using MQTT.

MQTT Sensor Daemon

This project works. I plan to add more sensor options.

My motivation came from wanting to easily integrate sensors attached to a raspberry pi to my Home Assistant. The real need came when I started using muplitple APC UPS devices to keep my network running through power outages. I wanted to montior and get notifications of power outages and how much battery reserve was left. Sadly, the APC UPS intergration only supported a single APCUPS. So I deced to create this daemon to generate MQTT updates so I can integrate an arbirary number of UPS devices into Home Assistant.

Sensors

The plan is to make an extensible platform for adding new sensors. Anything the raspberry pi can support. With a fallback command line parsing option.

General Configuration settings

poll_interval is the interval in seconds between reading the sensor

update_interval is the max time between sending data. This will silence MQTT messages if the sensor data has not changed since the last sent message. This controls what the maximum time is between MQTT messages about this sensor. Setting to 0 disables.

Temperature dht11 and dht22

Reads temperature and humidity from dht11 and dht22 sensors from a RaspberryPi's GPIO port.

Configuration examples for both:

{
    "type": "dht22",
    "name": "Environmental",
    "topic": "sensor/environment/office",
    "gpio": 4
},
{
    "type": "dht11",
    "name": "Environmental",
    "topic": "sensor/environment/garage",
    "gpio": 18
}

apcupsd

This sensor runs the apcaccess command to get the UPS status and sends a JSON message via MQTT.

Configuration example:

{
    "type": "apcups",
    "name": "UPS1",
    "topic": "sensor/ups1",
    "poll_interval": 5,
    "update_interval": 900,
    "host": "localhost",
    "port": 3551
},

Here is an example MQTT response:

{
 "TIMELEFT_MINUTES": "1440.0",
 "HOSTNAME": "pihost",
 "BCHARGE_PERCENT": "100.0",
 "STATUS": "ONLINE",
 "UPSNAME": "UPS3"
}

Requires installation and configuration of apcupsd. See Debian apcupsd for instructions on how to install apcupsd and to configure multiple UPSs connected to the same computer.

Reed Switches

Coming Soon

Gas Sensors

Coming Soon

Controllable

LED

Coming Eventually

Motors and Servos

Coming Eventually

Installation

The daemon is started on boot by systemd service.

pip3 install -r requirements.txt
mkdir /home/pi/mqttsensord/
cp mqttsensord.py mqttsensord.json /home/pi/mqttsensord/
sudo cp mqttsensord.service /lib/systemd/system/
sudo chmod 644 /lib/systemd/system/mqttsensord.service
sudo systemctl daemon-reload
sudo systemctl enable mqttsensord.service
sudo systemctl start mqttsensord.service
tail -f /home/pi/mqttsensord/mqttsensor.log

NOTE: You will need to edit /home/pi/mqttsensord/mqttsensord.json with your MQTT server credentials and configure your local sensors.

Future Plans and Features

• More sophisticated scheduling. Allow sensors to be polled at different rates.
• Add MQTT LWT support
• MQTT subscribe to channels to publish to local services

Troubleshooting

First, make sure you have the MQTT server, username, and password correct in the mqttsensord.json config file. Second, make sure the server you're talking to is listing on the correct port, 1883 by default. If you're using port 4883, make sure SSL is configured correctly on both ends. Third, make sure that the MQTT server you're connecting to is recieving the messages. One possible problem is if the reciever is not listening for the given topic. Adding the MQTT wildcard # as a listening topic is one way to get around this. Test connectivity with the mqtt command line tools to send a few test messages.

Home Assistant Integration

I use Home Assistant for tracking MQTT data and creating automations.

Example Home Assistant sensor configuration for a UPS sensors:

sensor:
  - platform: mqtt
    name: "ups3"
    state_topic: "sensor/ups3"
    value_template: "{{ value_json.STATUS }}"
    icon: mdi:car-battery
  - platform: mqtt
    name: "ups3_time_remaining"
    state_topic: "sensor/ups3"
    unit_of_measurement: minutes
    value_template: "{{ value_json.TIMELEFT_MINUTES | int }}"
    icon: mdi:timer
  - platform: mqtt
    name: "ups3_battery_charge"
    state_topic: "sensor/ups3"
    unit_of_measurement: percent
    value_template: "{{ value_json.BCHARGE_PERCENT | int }}"
    icon: mdi:battery
  - platform: mqtt
    name: "ups3_input_voltage"
    state_topic: "sensor/ups3"
    unit_of_measurement: V
    value_template: "{{ value_json.LINEV_VOLTS | int }}"
    icon: mdi:power-socket-us

Here is what it looks like in my Home Assistant dashboard: