Thingworx and EMS

Hi Wang, reading data from the sensor won't be that complicated it would require you to use the library for that sensor which if you don't have it already you will have to search/Google it and using that library you'll gather the data and push it to ThingWorx. For e.g. i used the REST API together with Python to deliver the payload but you can do the same with EMS, below code collected and pushed the data every 5 seconds from the sensor and then to the ThingWorx.

#!/usr/bin/python
import sys
import time
import json
import logging
import requests
import Adafruit_DHT
# enabling the logging
try:
    import http.client as http_client
except ImportError:
    #Python2
    import httplib as http_client
http_client.HTTPConnection.debuglevel=1
# defining the sensor type and the pin on which the data needs to be collected
sensor = 11
pin = 4
var = 1
#Webserver URL in TW
Webhost = "http://tw713:8080/Thingworx/Things/TempAndHumThing/Properties/*"
App_Key = "<appKey>" 
while var == 1:
 hum, temp = Adafruit_DHT.read_retry(sensor, pin)
 print('Temp={0:0.1f} *C  Hum={1:0.1f}%'.format(temp, hum))
 #ThingName = "TempAndHumThing"
 headers = {'Content-Type': 'application/json', 'appKey': App_Key}
 payload = {'temp': temp, 'hum': hum}
 response = requests.put(Webhost, headers=headers,json=payload, verify=True)
  
 time.sleep(5) # sleep for 5 seconds

There's another great reference/guide you could use from one of the community Blog post Using the C SDK to Deliver Data to ThingWorx from a Raspberry PI

Hope this would help.

Hi Wang,

Using the Sense HAT is not limited or specific to Thingworx, basically once you have your Pi and Sense HAT hooked and configured you could use the Sense HAT from anywhere using the existing APIs to read/write to/from it. The Thingworx tutorial on getting the basic information from the Raspberry Pi (i.e. CPU freq&temp) which you've already mentioned as having done successfully can be expanded to read Sense HAT specific sensor information. The key idea is that you can call from your Pi LUA script, i.e. a PiTemplate.lua script to read basic Pi information, other Python scripts that read sensor data from the Sense HAT and then supply thier results back to set Thingworx thing properties values. You can also send from Thingworx strings to be displayed on the Sense HAT LED matrix by defining a remote service on the Pi thing and call it with the string to be displayed. The most common operation however would be to read the Sense HAT's sensor data such as  position, humidity and pressure. I have used these resources to learn about reading the Sense HAT sensor data:

https://www.raspberrypi.org/learning/getting-started-with-the-sense-hat/

there is also a specific Astro Pi related page you can refer to:

https://astro-pi.org/get-involved/program-the-sense-hat/python/

There is of course a fully fledged API documentation page available for the Sense HAT:

https://pythonhosted.org/sense-hat/

What I found most useful were the examples from the getting started with the sense hat. I started from the existing LUA example.lua template and built a Pi specific one to include services and properties to read Sense HAT sensor data.

Just as an example, my PiTemplate.lua script looks like this:

module ("templates.PiTemplate", thingworx.template.extend)

properties.cpu_temperature  =     { baseType="NUMBER",  pushType="ALWAYS", value=0 }
properties.cpu_freq  =     { baseType="NUMBER",  pushType="ALWAYS", value=0 }
properties.cpu_volt  =     { baseType="NUMBER",  pushType="ALWAYS", value=0 }

properties.temperature = {baseType="NUMBER", pushType="ALWAYS", value=0}
properties.pressure = {baseType="NUMBER", pushType="ALWAYS", value=0}
properties.humidity = {baseType="NUMBER", pushType="ALWAYS", value=0}

properties.yaw = {baseType="NUMBER", pushType="ALWAYS", value=0}
properties.roll = {baseType="NUMBER", pushType="ALWAYS", value=0}
properties.pitch = {baseType="NUMBER", pushType="ALWAYS", value=0}

serviceDefinitions.GetSystemProperties(
output { baseType="BOOLEAN", description="" },
description { "updates properties" }
)

services.GetSystemProperties = function(me, headers, query, data)
log.trace("[PiTemplate]","########### in GetSystemProperties#############")
queryHardware()
queryOrientation()
queryEnvirons()
return 200, true
end

function queryOrientation()

local f = io.popen("python /home/pi/twx/microserver/etc/custom/templates/get_pitch.py")
local s = f:read("*a")
properties.pitch.value = s
f:close()
log.debug("[PiTemplate]", string.format("Pitch: %.2f", properties.pitch.value))

local f = io.popen("python etc/custom/templates/get_roll.py")
local s = f:read("*a")
properties.roll.value = s
f:close()
log.debug("[PiTemplate]", string.format("Roll: %.2f", properties.roll.value))

local f = io.popen("python etc/custom/templates/get_yaw.py")
local s = f:read("*a")
properties.yaw.value = s
f:close()
log.debug("[PiTemplate]", string.format("Yaw: %.2f", properties.yaw.value))

end

function queryEnvirons()

local f = io.popen("python etc/custom/templates/get_humidity.py")
local s = f:read("*a")
properties.humidity.value = s
f:close()
log.debug("[PiTemplate]", string.format("Humidity: %5.2f", properties.humidity.value))

local f = io.popen("python etc/custom/templates/get_pressure.py")
local s = f:read("*a")
properties.pressure.value = s
f:close()
log.debug("[PiTemplate]", string.format("Pressure: %6.1f", properties.pressure.value))

local f = io.popen("python etc/custom/templates/get_temperature.py")
local s = f:read("*a")
properties.temperature.value = s
f:close()
log.debug("[PiTemplate]", string.format("Temperature: %4.1f", properties.temperature.value))

end

function queryHardware()
local tempCmd = io.popen("vcgencmd measure_temp")
local freqCmd = io.popen("vcgencmd measure_clock arm")
local voltCmd = io.popen("vcgencmd measure_volts core")
local s = tempCmd:read("*a")
s = string.match(s,"temp=(%d+\.%d+)");
log.debug("[PiTemplate]",string.format("temp %.1f",s))
properties.cpu_temperature.value = s
s = freqCmd:read("*a")
log.debug("[PiTemplate]",string.format("raw freq %s",s))
s = string.match(s,"frequency%(45%)=(%d+)");
s = s/1000000
log.debug("[PiTemplate]",string.format("scaled freq %d",s))
properties.cpu_freq.value = s
s = voltCmd:read("*a")
log.debug("[PiTemplate]",string.format("raw volts %s", s))
s = string.match(s,"volt=(%d+\.%d+)");
log.debug("[PiTemplate]",string.format("scaled volts %.1f", s))
properties.cpu_volt.value = s
end

tasks.refreshProperties = function(me)
log.trace("[PiTemplate]","~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In tasks.refreshProperties~~~~~~~~~~~~~ ")
queryHardware()
queryOrientation()
queryEnvirons()
end

The python scripts for doing the actual reading look like this example:

def get_pitch():

    from sense_hat import SenseHat

    sense = SenseHat()
    sense.clear()

    o = sense.get_orientation()
    pitch = round(o["pitch"],1)
    return pitch
    
print("{0}". format(get_pitch()))

And they all follow a similar approach, defined in the Astro Pi and the Raspberry Pi Sense Hat web pages mentioned above.

One mention I'd like to make is on how to get location information while using the Pi board. The Sense HAT has no such feature but given that the Raspberry Pi has several USB ports, inserting a USB GPS dongle is pretty straight forward while connecting and reading location information from the dongle is not a trivial task but neither is it very difficult given the amount of resources already available about connecting and reading NMEA data from a USB GPS dongle.

Hope this info helps.

Regards,

Denis

Hi Wang, Aanjan Ravi​,

I am trying Raspberry Pi Quickstart documentation and stuck at Step 10(Run LSR). I am using EMS provided in the guide in beginning steps.

When i am running LSR it starts but it is giving error as

[INFO ] 2017-03-06 17:20:46,870 PiThing: ------------------------------------------------

[INFO ] 2017-03-06 17:20:48,838 PiThing: -- Starting script --------------------------

[INFO ] 2017-03-06 17:20:48,838 PiThing: Registering core callback handler

[INFO ] 2017-03-06 17:20:48,838 PiThing: Starting main loop

[INFO ] 2017-03-06 17:20:48,838 PiThing: Calling lifecycle start listeners.

[INFO ] 2017-03-06 17:20:48,838 shapes.propsubscribe: Initialized

[INFO ] 2017-03-06 17:20:48,839 thingworx.handler: Creating a new handler.

[WARN ] 2017-03-06 17:20:48,943 HttpClient::processReq: Authentication requested but no credentials supplied

[INFO ] 2017-03-06 17:20:48,944 PiThing: Error occured while accessing EMS. Checking isConnected.

[WARN ] 2017-03-06 17:20:49, 46 HttpClient::processReq: Authentication requested but no credentials supplied

[INFO ] 2017-03-06 17:20:49, 46 PiThing: MicroServer is now available.

[INFO ] 2017-03-06 17:20:49, 46 PiThing: EMS is available: true, online: false

config.json

{

"ws_servers": [{

"host": "guragidev01.strykercorp.com",

"port": 8081

}],

"http_server":  {

    "host": "10.117.255.20",

    "port": 8081

},

"appKey": "213abab3-a234-4357-a1f7-49e59d6ac8db",

"logger":   {

    "level":    "DEBUG"

},

"auto_bind":    [{

        "name": "PiThing",

        "gateway":  false

    }],

"certificates": {

    "validate": false,

    "allow_self_signed":    true

},

"ws_connection":    {

    "encryption":   "none",

    "verbose":  true,

    "msg_timeout":  1000

}

}

PiTemplate.lua

module("templates.PiTemplate", thingworx.template.extend)

properties.cpu_temperature = { baseType="NUMBER", pushType="ALWAYS", value=0 }

properties.cpu_freq = { baseType="NUMBER", pushType="ALWAYS", value=0 }

properties.cpu_volt = { baseType="NUMBER", pushType="ALWAYS", value=0 }

serviceDefinitions.GetSystemProperties(

output { baseType="BOOLEAN", description="" },

description { "updates properties" }

)

-- service input parameters

-- me: table that refers to the Thing

-- headers: table of HTTP headers

-- query: query parameters from the HTTP request

-- data: lua table containing the parameters to the service call.

services.GetSystemProperties = function(me, headers, query, data)

log.trace("[PiTemplate]","########### in GetSystemProperties#############")

queryHardware()

--  if properties are successfully updated, return HTTP 200 code with a true service return value

return 200, true

end

function queryHardware()

-- use the vcgencmd shell command to get raspberry pi system values and assign to variables

-- measure_temp returns value in Celsius

-- measure_clock arm returns value in Hertz

-- measure_volts returns balue in Volts

local tempCmd = io.popen("vcgencmd measure_temp")

local freqCmd = io.popen("vcgencmd measure_clock arm")

local voltCmd = io.popen("vcgencmd measure_volts core")

--   set property temperature

local s = tempCmd:read("*a")

s = string.match(s,"temp=(%d+\.%d+)");

log.debug("[PiTemplate]",string.format("temp %.1f",s))

properties.cpu_temperature.value = s

--  set property frequency

s = freqCmd:read("*a")

log.debug("[PiTemplate]",string.format("raw freq %s",s))

s = string.match(s,"frequency%(45%)=(%d+)");

s = s/1000000

log.debug("[PiTemplate]",string.format("scaled freq %d",s))

properties.cpu_freq.value = s

--  set property volts

s = voltCmd:read("*a")

log.debug("[PiTemplate]",string.format("raw volts %s", s))

s = string.match(s,"volt=(%d+\.%d+)");

log.debug("[PiTemplate]",string.format("scaled volts %.1f", s))

properties.cpu_volt.value = s

end

tasks.refreshProperties = function(me)

log.trace("[PiTemplate]","~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In tasks.refreshProperties~~~~~~~~~~~~~ ")

queryHardware()

end

Config.lua file

scripts.log_level = "INFO"

scripts.PiThing = {

    file = "thing.lua",

    template = "PiTemplate",

    scanrate = 1000,

    taskrate = 3000

}

scripts.rap_host = "guragidev01.strykercorp.com"

scripts.rap_port = 8081

Since it worked for you can you please help what is the issue.

Is my below code ok?  When i tried using 127.0.0.1 is was not even connecting to EMS.

scripts.rap_host = "guragidev01.strykercorp.com"

scripts.rap_port = 8081

What is difference between WS or Http? I am new to Thingworx so excuse me for this basic question.