In Greek mythology, Copreus (Κοπρεύς) was King Eurystheus' herald. He announced Heracles' Twelve Labors. [wiki]

This library provides a framework to write a device driver for the raspberry pi that are connected to MQTT.

Thus, Copreus takes commands from the king (MQTT) and tells the hero (device) what it labors are. Further, Copreus reports to the king whatever the hero has to tell him.


Copreus is part of the collection of mqtt based microservices pelops. An overview on the microservice architecture and examples can be found at (http://gitlab.com/pelops/pelops).

For Users

Installation Core-Functionality

Prerequisites for the core functionality are:

sudo apt install python3 python3-pip
sudo pip3 install RPi.GPIO pelops

Install via pip:

sudo pip3 install copreus

To update to the latest version add --upgrade as prefix to the pip3 line above.

Install via gitlab (might need additional packages):

git clone git@gitlab.com:pelops/copreus.git
cd copreus
sudo python3 setup.py install

This will install the following shell scripts:

• copreus - alias for copreus_drivermanager
• copreus_drivermanager - driver manager can instantiate several driver
• copreus_adc - analog digital converter via spi
• copreus_bme280 - bosch bme280 sensor via SMBus
• copreus_dac - digital analog converter via spi
• copreus_dht - DHT11/DHT22/AM2302
• copreus_epaperdirect - Waveshare e-Papers 1.54inch/2.13inch/2.9inch via spi -
• copreus_epapersimple - Waveshare e-Papers 1.54inch/2.13inch/2.9inch via spi
• copreus_input - generic gpio input
• copreus_output - generic gpio output
• copreus_rotaryencoder - rotary encoder like ky-040 with software solutions for debouncing and direction detection.
• copreus_rotaryencoder2 - rotary encoder like ky-040 together with schmitttriggers for debouncing and a flipflop for direction detection in hardware.

The script cli arguments are:

• '-c'/'--config' - config file (mandatory)
• '--version' - show the version number and exit

Additional Prerequisites for Drivers

Some drivers like Input and Output don't need additional packages. The others need additional prerequisites to be used (they will be installed without them).

ADC and DAC

sudo pip3 install spidev

bme280

sudo pip3 install smbus2 RPi.bme280

DHT

sudo apt install build-essential python-dev
git clone https://github.com/adafruit/Adafruit_Python_DHT.git
cd Adafruit_Python_DHT
sudo python3 setup.py install

epaperdirect

sudo apt install libopenjp2-7 libtiff5
sudo pip3 install spidev Pillow

epapersimple

sudo apt install libopenjp2-7 libtiff5
sudo pip3 install spidev Pillow

Install Everything at Once

sudo apt install python3 python3-pip build-essential python-dev libopenjp2-7 libtiff5
sudo pip3 install RPi.GPIO paho-mqtt pyyaml spidev Pillow smbus2 RPi.bme280 pelops
git clone https://github.com/adafruit/Adafruit_Python_DHT.git
cd Adafruit_Python_DHT
sudo python3 setup.py install
cd ..
sudo pip3 install copreus

Further ubuntu and python packages may be needed by example and tests. For example, test_epaper.py requires that the ubuntu package fonts-freefont-ttf is installed.

YAML-Config

A yaml file must contain two root blocks:

• mqtt - mqtt-address, mqtt-port, and path to credentials file credentials-file (a file consisting of two entries: mqtt-user, mqtt-password)
• logger - logger configuration. log level and output file.
• driver or drivers. drivers is a list of driver entries with two additional parameters per driver: active and name. a driver entry contains at least (driver implementation might add additional ones): type, name, topic-pub (list of key/value pairs), and topic-sub (list of key/value pairs).

Currently, pyyaml is yaml 1.1 compliant. In pyyaml On/Off and Yes/No are automatically converted to True/False. This is an unwanted behavior and deprecated in yaml 1.2. In copreus this autoconversion is removed. Thus, On/Off and Yes/No are read from the yaml file as strings (see module baseclasses.myconfigtools).

Examples

Config for Driver Input

Can be started with copreus_input -c config.yaml -v. More information in the wiki.

config.yaml:

mqtt:
    mqtt-address: localhost
    mqtt-port: 1883
    credentials-file: ~/credentials.yaml
    log-level: INFO

logger:
    log-level: DEBUG
    log-file: copreus.log  

driver:
    type: input
    pin:  23
    topics-pub:
        button_pressed: /test/button/pressed
        button_state:   /test/button/state
    mqtt-translations:
        button_pressed: PRESSED
        button_state-open: OPEN
        button_state-closed: CLOSED        

credentials.yaml:

mqtt:
    mqtt-user: user
    mqtt-password: password

Config for DriverManager

Can be started with copreus -c config.yaml -v. More information at wiki, wiki, and wiki.

config.yaml:

mqtt:
    mqtt-address: localhost
    mqtt-port: 1883
    credentials-file: ~/credentials.yaml
    log-level: INFO

logger:
    log-level: DEBUG
    log-file: copreus.log
    
drivers:
    - name: button1 
      type: input
      pin:  23
      topics-pub:
          button_pressed: /test/button/pressed
          button_state:   /test/button/state
      mqtt-translations:
          button_pressed: PRESSED
          button_state-open: OPEN
          button_state-closed: CLOSED   
      active: true       
    - name: led1
      type: output
      pin: 21
      initially-closed: false
      physical-closed: low      
      topics-sub:
          closed: /test/closed
      mqtt-translations:
          closed-true: ON
          closed-false: OFF
      active: false          

credentials.yaml:

mqtt:
    mqtt-user: user
    mqtt-password: password

systemd

• add systemd example.

For Developers

Getting Started

The project consists of three main packages:

• baseclasses - ADriver and additional base- and utilityclasses
• drivermanager - DriverManager and DriverFactory
• drivers - all implemented driver

Each driver must be a silbiling of ADriver. A new driver must be added to the DriverFactory, drivers.__init__.py, setup.py and README.md. Further, config example must be placed in /tests.

A good starting point is to look at the two generic driver Ìnput and Output as well as DHT.

Additional Dependencies

Next to the dependencies listed above, you need to install the following:

sudo apt install pandoc
sudo pip3 install pypandoc

Todos

• Add more driver
• SMBus base class
• ...

Misc

The code is written for python3 (and tested with python 3.5 on an Raspberry Pi Zero with Raspbian Stretch).

Merge requests / bug reports are always welcome.