EdgeMicroserver - Capturing location information

[steveja]

Hi,

I am trying to capture location information (i.e. longitude, latitude and elevation) from a file on a Linux based device. I am basing my approach on the Vending machine example from the Thingworx Fundamentals course. My approach has been to modify simulator_script.lua to read the values for Prop_Equipment1Temp and Prop_Equipment1Hum from files rather than randomly generate the values as now.

I have been somewhat successful in this approach and now I can change the value of  temperature and humidity in the files on the device and see the changes reflected back to my mashup on the Thingworx. server.

Now I want to add location information and bind to the geolocation property of my EdgeVendingMachine thing on the server.

I'm sure I will work it out in the end but if someone can point me in the right direction (i.e. which lua files I need to edit) I could save some time.

I'm not sure what line(s) I should add to simulator.lua and simulator_script.lua as the LOCATION type is a composite type rather than a simple string or number.

Any ideas welcome

thanks

Steve

[paic]

Hi Steve, if you look at the example files included and search for Location you'll find some helpful information on how to accomplish that.

Look at the following files

/etc/custom/templates/example.lua

and the handler it invokes

/etc/thingworx/lua/handlers/generator.lua

Hopefully that gets you going in the right direction.

[steveja]

Hi Pai,

Thanks for the help. I thought about this first but noticed that any 'location' examples were in example.lua and the generator.lua script whereas temperature and humidity examples were in simulator.lua and simulator_script.lua  so I never took it very far. Today I've been trying to combine the two together.

I Put

properties.Pushed_Random_Location = { baseType="LOCATION", pushType="ALWAYS", handler="generator", functionType="random"} from examples.lua

into the simulator script and I was able to bind the Pushed_Random_Location  property to my EdgeVendingMachine2 thing but on running it , it didn't work. I got the error

[ERROR] 2013-11-06 15:01:35,790 EdgeVendingMachine2: Error occured in handler bb_generator.read. property: Pushed_Random_Location, msg: ....3-linux-arm/MicroServer/etc/thingworx/lua/utils.lua:256: bad argument #1 to 'find' (string expected, got nil)

Looking at the code I thought it might be missing the 'Value'  parameter so I tried

properties.Pushed_Random_Location = { baseType="LOCATION", pushType="ALWAYS", value={ latitude=54.92, longitude=-1.82, elevation=103 }, handler="bb_generator", functionType="random"}

But I got the same error. Then I tried

properties.Pushed_InMemory_Location = { baseType="LOCATION", pushType="ALWAYS", value={ latitude=54.92, longitude=-1.82, elevation=103 }}

This gave no errors in the output but still didn't alter my location in Thingworx

I'll try a few more things tomorrow. If you can put me in touch with someone that has done this sort of thing before I'd much appreciate it.

Maybe if I tried this straight after I did the course instead of two months later I may have had a better chance.

Thanks for you help

Steve