MQTT IO

Exposes general purpose inputs and outputs (GPIO), hardware sensors and serial devices to an MQTT server. Ideal for single-board computers such as the Raspberry Pi.

Visit the documentation for more detailed information.

Supported Hardware

Hardware support is provided by specific GPIO, Sensor and Stream modules. It's easy to add support for new hardware and the list is growing fast.

GPIO Modules

• Beaglebone GPIO (beaglebone)
• Linux Kernel 4.8+ libgpiod (gpiod)
• GPIO Zero (gpiozero)
• MCP23017 IO expander (mcp23017)
• Orange Pi GPIO (orangepi)
• PCF8574 IO expander (pcf8574)
• PCF8575 IO expander (pcf8575)
• PiFace Digital IO 2 (piface2)
• Raspberry Pi GPIO (raspberrypi)

Sensors

• ADS1x15 analog to digital converters (ads1x15)
• AHT20 temperature and humidity sensor (aht20)
• BH1750 light level sensor (bh1750)
• BME280 temperature, humidity and pressure sensor (bme280)
• BME680 temperature, humidity and pressure sensor (bme680)
• DHT11/DHT22/AM2302 temperature and humidity sensors (dht22)
• DS18S20/DS1822/DS18B20/DS1825/DS28EA00/MAX31850K temperature sensors (ds18b)
• HCSR04 ultrasonic range sensor (connected to the Raspberry Pi on-board GPIO) (hcsr04)
• INA219 DC current sensor (ina219)
• LM75 temperature sensor (lm75)
• MCP3008 analog to digital converter (mcp3008)
• ADXl345 3-axis accelerometer up to ±16g (adxl345)

Streams

• Serial port (serial)
• PN532 NFC/RFID reader (pn532)

Installation

Requires Python 3.6+

pip3 install mqtt-io

Execution

python3 -m mqtt_io config.yml

Configuration Example

Configuration is written in a YAML file which is passed as an argument to the server on startup.

See the full configuration documentation for details.

The following example will configure the software to do the following:

• Publish MQTT messages on the home/input/doorbell topic when the doorbell is pushed and released.
• Subscribe to the MQTT topic home/output/port_light/set and change the output when messages are received on it.
• Periodically read the value of the LM75 sensor and publish it on the MQTT topic home/sensor/porch_temperature.
• Publish any data received on the /dev/ttyUSB0 serial port to the MQTT topic home/serial/alarm_system.
• Subscribe to the MQTT topic home/serial/alarm_system/send and send any data received on that topic to the serial port.

mqtt:
  host: localhost
  topic_prefix: home

# GPIO
gpio_modules:
  # Use the Raspberry Pi built-in GPIO
  - name: rpi
    module: raspberrypi

digital_inputs:
  # Pin 0 is an input connected to a doorbell button
  - name: doorbell
    module: rpi
    pin: 0

digital_outputs:
  # Pin 1 is an output connected to a light
  - name: porch_light
    module: rpi
    pin: 1

# Sensors
sensor_modules:
  # An LM75 sensor attached to the I2C bus
  - name: lm75_sensor
    module: lm75
    i2c_bus_num: 1
    chip_addr: 0x48
  # An INA219 sensor attached to the I2C bus
  - name: ina219_sensor
    module: ina219
    i2c_bus_num: 1
    chip_addr: 0x43


sensor_inputs:
  # lm75 - The configuration of the specific sensor value to use (LM75 only has temperature)
  - name: porch_temperature
    module: lm75_sensor
  # ina219 - The configuration of the specific sensor value to use (4 options for the ina219 sensor)
  - name: power
    type: power
    module: ina219_sensor
  - name: bus_voltage
    type: bus_voltage
    module: ina219_sensor
  - name: current
    type: current
    module: ina219_sensor
  - name: shunt_voltage
    type: shunt_voltage
    module: ina219_sensor

# Streams
stream_modules:
  # A serial port to communicate with the house alarm system
  - name: alarm_system
    module: serial
    device: /dev/ttyUSB0
    baud: 9600