Measurement simulator demo in Python

.gitignore

@@ -1,3 +1,4 @@
 
 .project
 .pydevproject
+*.pyc

devicecreation/IoTDeviceCreation.py

@@ -17,9 +17,10 @@
 from requests.auth import HTTPBasicAuth
 import json
 
-host = 'https://humblescience.us.cumulocity.com'
-username = 'testuser@softwareag.com'
-password = 'test123!'
+
+host = 'https://TENANT.cumulocity.com'
+username = 'testuser'
+password = 'password'
 
 auth = HTTPBasicAuth(username, password)
 session = requests.Session()
@@ -55,11 +56,16 @@
 
 # Check whether device is already registered.
 def isDeviceRegistered(deviceIdPath, deviceId):
- url = host + deviceIdPath + deviceId
+ return getInternalDeviceId(deviceIdPath, deviceId) != None
+
+def getInternalDeviceId(deviceId):
+ url = host + '/identity/externalIds/c8y_Serial/' + deviceId
  response = session.get(url)
- #print ('Response -> ' + str(response.json()))
- print ('Response -> ' + str(response.status_code))
- return response.status_code == 200
+ #print ('Response -> ' + str(response.status_code))
+ if response.status_code == 200:
+ jsonResponse = response.json()
+ return jsonResponse['managedObject']['id']
+ return None
 
 # Create the device from template
 def createDevice(deviceName, deviceType, deviceId):
@@ -70,10 +76,10 @@ def createDevice(deviceName, deviceType, deviceId):
  deviceDescriptionJson['c8y_Hardware']['serialNumber'] = deviceId
  print (json.dumps(deviceDescriptionJson, indent = 4))
  response = session.post(url, json=deviceDescriptionJson)
- print ('Response -> ' + str(response.status_code))
+ #print ('Response -> ' + str(response.status_code))
  if (response.status_code == 201):
  newDeviceDetails = response.json()
- print ("New device created [id=%s]" % newDeviceDetails['id'])
+ #print ("New device created [id=%s]" % newDeviceDetails['id'])
  return newDeviceDetails;
  return None 
  # print ('Response -> ' + json.dumps(response.json(), indent = 4))
@@ -90,28 +96,28 @@ def registerDevice(deviceId, newDeviceDetails):
  }""")
  associateDescriptionJson['externalId'] = deviceId 
  response = session.post(url, json=associateDescriptionJson)
- print ('Response -> ' + str(response.status_code))
- print(response.text)
+ # print ('Response -> ' + str(response.status_code))
+ #print(response.text)
  if (response.status_code == 201):
  newDeviceAssoc = response.json()
- print ("New device [id=%s] associated with external id ['c8y_serial'=%s]" % (newDeviceAssoc['managedObject']['id'], newDeviceAssoc['externalId']))
+ print ("New device [id=%s] associated with external id ['c8y_Serial'=%s]" % (newDeviceAssoc['managedObject']['id'], newDeviceAssoc['externalId']))
  # print ('Response -> ' + json.dumps(response.json(), indent = 4))
 
 
-
-def checkAndRegisterDevice(deviceName, deviceType, deviceId):
- if isDeviceRegistered('/identity/externalIds/c8y_Serial/', deviceId): 
- print('Device [id=%s] already registered.' % deviceId) 
+def checkAndRegisterDevice(deviceName, deviceType, externalId):
+ internalDeviceId = getInternalDeviceId(externalId)
+ if internalDeviceId != None: 
+ print('Managed object [external id=%s] already registered with internal id=%s.' % (externalId, internalDeviceId))
+ return internalDeviceId
  else:
- print('Device [id=%s] not registered, registering as new device ...' % deviceId)
- newDeviceDetails = createDevice(deviceName, deviceType, deviceId)
+ print('Managed object [id=%s] not registered, registering as new device ...' % externalId)
+ newDeviceDetails = createDevice(deviceName, deviceType, externalId)
  if (newDeviceDetails != None):
- registerDevice(deviceId, newDeviceDetails) 
+ registerDevice(externalId, newDeviceDetails)
+ return newDeviceDetails['id'] 
  else:
- print("Error creating new device! [id=%s]"%deviceId)
-
-
-
+ print("Error creating new device! [id=%s]", externalId)
+ return None
 
 if __name__ == "__main__":
  checkAndRegisterDevice('MyDevice', 'MyDeviceType', 'my-device-1')

measurement_generation/IoTDeviceSimulator.py

@@ -0,0 +1,104 @@
+'''
+This script aims to showcase how to generate measurements for Cumulocity devices. 
+In this example, we demonstrate necessary steps to generate simulated sensor readings through Cumulocity's REST API. 
+This example automatically creates devices that host the generated readings.
+
+Please refer to the documentation for further details on the API:
+https://cumulocity.com/guides/reference/rest-implementation/
+
+Created on Dec 10, 2019
+
+@author: JHUM
+'''
+
+import requests
+from requests.auth import HTTPBasicAuth
+import json
+import datetime
+import random
+from threading import Thread
+from time import sleep
+
+# Get the session information from the IoTDeviceCreation module
+import sys
+sys.path.append('../devicecreation') 
+from IoTDeviceCreation import checkAndRegisterDevice, host, session
+
+SENSOR_READING_TIME_DELAY = 10.0
+INITIAL_SENSOR_VALUE = 100.0
+POSITIVE_CHANGE_PROBABILITY = 0.5
+
+class DeviceDescription:
+
+ c8y_id = "" # this will be given when we create and register device
+
+ def __init__(self, name, type, measurementType, measurementName, measurementUnit):
+ self.name = name
+ self.type = type
+ self.measurementType = measurementType
+ self.measurementName = measurementName
+ self.measurementUnit = measurementUnit
+
+
+sensorDevices = [ DeviceDescription("TempSensor-1", "TemperatureSensor", "c8y_Temperature", "T", "C"), 
+ DeviceDescription("PressureSensor-1", "PressureSensor", "c8y_Pressure", "P", "Pa") ]
+
+
+def createDevice(name, id, measurementName):
+ return
+
+def createMeasurement(deviceDescription, value):
+ measurementData = {}
+ measurementData['source'] = { "id" : deviceDescription.c8y_id }
+ measurementData['time'] = formatTimestamp(datetime.datetime.utcnow())
+ measurementData['type'] = deviceDescription.measurementType
+ measurementData[deviceDescription.measurementType] = { deviceDescription.measurementName : { "value": value, "unit" : deviceDescription.measurementUnit } }
+ #print (json.dumps(measurementData, indent = 4))
+ status = submitMeasurement(measurementData)
+ print("Measurement submitted for deviceId='%s' value='%s' ... result -> %s"%(deviceDescription.c8y_id, value, status))
+
+def sensorLifecycle(deviceDescription):
+ value = INITIAL_SENSOR_VALUE*random.random()
+ while True:
+ delta = (INITIAL_SENSOR_VALUE * 0.10)*random.random()
+ sleep(SENSOR_READING_TIME_DELAY)
+
+ if POSITIVE_CHANGE_PROBABILITY > random.random():
+ value += delta
+ else:
+ value -= delta 
+ createMeasurement(deviceDescription, value)
+
+def generateSimulatedMeasurements():
+
+ for deviceDescription in sensorDevices:
+ if deviceDescription.c8y_id == None:
+ print("Ignoring device with no managed object -> " + deviceDescription.name)
+ continue
+
+ thread = Thread(target=sensorLifecycle, args=(deviceDescription, ))
+ thread.start()
+ print ("Lifecycle for sensor '%s' with id='%s' started."% (deviceDescription.name, deviceDescription.c8y_id))
+
+
+def formatTimestamp(timestamp):
+ return timestamp.isoformat(timespec='milliseconds')
+
+
+def submitMeasurement(measurementJson):
+ session.headers.update({
+ 'Content-Type': 'application/json',
+ 'Accept': 'application/vnd.com.nsn.cumulocity.measurement+json'
+ })
+ url = host + '/measurement/measurements'
+ response = session.post(url, json=measurementJson)
+ #print(str(response.text))
+ return response.status_code
+
+
+if __name__ == "__main__":
+ for deviceDescription in sensorDevices:
+ deviceDescription.c8y_id = checkAndRegisterDevice(deviceDescription.name, deviceDescription.type, deviceDescription.name)
+
+ generateSimulatedMeasurements()
+

measurement_generation/readme.md

@@ -0,0 +1,39 @@
+# IoT Device Simulator
+
+This script aims to showcase how to generate measurements for Cumulocity devices.
+In this example, we demonstrate necessary steps to generate simulated sensor readings through
+Cumulocity's REST API. This example automatically creates devices that host the generated readings.
+
+If you haven't done so, please review the previous example [devicecreation](../devicecreation/readme.md) to understand how the devices in this demo script are generated.
+
+Please refer to the [online documentation](https://cumulocity.com/guides/reference/rest-implementation) for further details on the API.
+
+
+## Setup
+
+Pre-requisites:
+- Python (tested on Python 3.6+)
+- 'json' and 'requests' packages installed (e.g. pip install xxx)
+- Cumulocity tenant with Basic Authentication enabled and your user role allows for creation of new managed objects.
+- devicecreation/IoTDeviceCreation.py script to automatically create sample devices in your tenant.
+
+Open the IoTDeviceCreation.py script, and modify the host, name, and password.
+
+## Running
+
+- Run the python script though your console, ensuring the Python environment and required packages are available in the path.
+
+```
+ >> python ./IoTDeviceSimulator.py
+```
+
+This will create two new devices: one temperature sensor device and one pressure sensor device. Note that if the devices already exist, they won't be created again. Navigate to the 'Device Management' section of your tenant and open 'All Devices'. You should see the new device created and registered.
+
+![trigger](./c8y-screenshot-3.png) 
+
+You should also see a menu section for your devices called 'measurements'. Select this to show the current measurements being generated for each of the devices.
+
+![trigger](./c8y-screenshot-4.png) 
+
+
+