VictronGX_Custom_Sensors/dbus-node-red-temp-outside/temp_outside.py

#!/usr/bin/env python
 
# import normal packages
import platform 
import logging
import sys
import os
import sys
if sys.version_info.major == 2:
    import gobject
else:
    from gi.repository import GLib as gobject
import sys
import time
import requests # for http GET
 
# our own packages from victron
sys.path.insert(1, os.path.join(os.path.dirname(__file__), '/opt/victronenergy/dbus-systemcalc-py/ext/velib_python'))
from vedbus import VeDbusService


class NodeRedMeterTemperature:
  def __init__(self, servicename, deviceinstance, paths, productname='External temp sensor', connection='Node RED HTTP JSON service'):
    self._dbusservice = VeDbusService("{}.http_{:02d}".format(servicename, deviceinstance))
    self._paths = paths
 
    logging.debug("%s /DeviceInstance = %d" % (servicename, deviceinstance))
 
    # Create the management objects, as specified in the ccgx dbus-api document
    self._dbusservice.add_path('/Mgmt/ProcessName', __file__)
    self._dbusservice.add_path('/Mgmt/ProcessVersion', 'Python ' + platform.python_version())
    self._dbusservice.add_path('/Mgmt/Connection', connection)
 
    # Create the mandatory objects
    self._dbusservice.add_path('/DeviceInstance', deviceinstance)
    self._dbusservice.add_path('/ProductId', 0xA162) #from dbus spy with wire attached sensor
    self._dbusservice.add_path('/FilterLength', 10)
    self._dbusservice.add_path('/Offset', 0)
    self._dbusservice.add_path('/Scale', 1)
    self._dbusservice.add_path('/ProductName', productname)
    self._dbusservice.add_path('/CustomName', "Temperatur Außen")
    self._dbusservice.add_path('/TemperatureType', 2) # 0=battery; 1=fridge; 2=generic
    self._dbusservice.add_path('/FirmwareVersion', 1.0)
    self._dbusservice.add_path('/HardwareVersion', 0)
    self._dbusservice.add_path('/Connected', 1)
    self._dbusservice.add_path('/Serial', 1337)
    self._dbusservice.add_path('/UpdateIndex', 0)
 
    # add path values to dbus
    for path, settings in self._paths.items():
      self._dbusservice.add_path(
        path, settings['initial'], gettextcallback=settings['textformat'], writeable=True, onchangecallback=self._handlechangedvalue)
 
    # last update
    self._lastUpdate = 0
 
    # add _update function 'timer'
    gobject.timeout_add(2000, self._update) # pause 2000ms before the next request
    
    # add _Status 'timer' to get feedback in log every 5minutes
    gobject.timeout_add(self._getStatusInterval()*60*1000, self._Status)
 
  def _getStatusInterval(self):
    value = 1
    
    if not value: 
        value = 0
    
    return int(value)
  
  def _getNodeRedData(self):
    URL = "http://localhost:1880/temps"
    temperature_r = requests.get(url = URL)
    
    # check for response
    if not temperature_r:
        raise ConnectionError("No response from NodeRed - %s" % (URL))
    
    meter_data = temperature_r.json()     
    
    # check for Json
    if not meter_data:
        raise ValueError("Converting response to JSON failed")
    
    
    return meter_data
 
 
  def _Status(self):
    logging.info("Last _update: %s" % (self._lastUpdate))
    logging.info("Last '/Temperature': %s" % (self._dbusservice['/Temperature']))
    return True
 
  def _update(self):   
    try:
       #get data from NodeRed 3em
       meter_data = self._getNodeRedData()
       
       #send data to DBus
       self._dbusservice['/Temperature'] = meter_data['outside']
       #logging
       logging.debug("Temperature Outside (/Temperature): %s" % (self._dbusservice['/Temperature']))
       logging.debug("---");
       
       # increment UpdateIndex - to show that new data is available
       index = self._dbusservice['/UpdateIndex'] + 1  # increment index
       if index > 255:   # maximum value of the index
         index = 0       # overflow from 255 to 0
       self._dbusservice['/UpdateIndex'] = index

       #update lastupdate vars
       self._lastUpdate = time.time()              
    except Exception as e:
       logging.critical('Error at %s', '_update', exc_info=e)
       
    # return true, otherwise add_timeout will be removed from GObject - see docs http://library.isr.ist.utl.pt/docs/pygtk2reference/gobject-functions.html#function-gobject--timeout-add
    return True
 
  def _handlechangedvalue(self, path, value):
    logging.debug("someone else updated %s to %s" % (path, value))
    return True # accept the change
 


def main():
  #configure logging
  logging.basicConfig(      format='%(asctime)s,%(msecs)d %(name)s %(levelname)s %(message)s',
                            datefmt='%Y-%m-%d %H:%M:%S',
                            level=logging.INFO,
                            handlers=[
                                logging.FileHandler("%s/current.log" % (os.path.dirname(os.path.realpath(__file__)))),
                                logging.StreamHandler()
                            ])
 
  try:
      logging.info("Start");
  
      from dbus.mainloop.glib import DBusGMainLoop
      # Have a mainloop, so we can send/receive asynchronous calls to and from dbus
      DBusGMainLoop(set_as_default=True)
     
      #formatting 
      _celcius = lambda p, v: (str(round(v, 2)) + ' °C')
     
      #start our main-service
      pvac_output = NodeRedMeterTemperature(
        servicename='com.victronenergy.temperature',
        deviceinstance=18,
        paths={
          '/Temperature': {'initial': 0, 'textformat': _celcius},
        })
     
      logging.info('Connected to dbus, and switching over to gobject.MainLoop() (= event based)')
      mainloop = gobject.MainLoop()
      mainloop.run()            
  except Exception as e:
    logging.critical('Error at %s', 'main', exc_info=e)
if __name__ == "__main__":
  main()