Creating a harmonized and provisioned sensor for test
The OpenWeatherMapSensor repository contains a bridge between https://openweathermap.org/ and XMPP, and provides regular readouts, local storage of historical values, as well as harmonized interfaces for sensor data, control and provisioning. It can be used for testing purposes, or to introduce weather information into your smar city projects.
The sensor is provisioned, meaning it can be claimed by an owner. Access to, and authorization to read data (wholly or partially), as well as to enable or disable it, is controlled by the owner. You can use any client that supports IoT Harmonization to control the sensor. Examples include the TAG ID App, or the Simple IoT Client in the IoT Gateway repository. You can also access the sensor programmatically, via NuGets, as described in Mastering Internet of Things.
Download
You don’t need to clone and compile the OpenWeatherMapSensor repository repository to run the sensor on your machine. You can download it directly from the following link, and install it. Note that you may need to approve running the file on your machine, depending on what protection software you use: https://lab.tagroot.io/Downloads/OpenWeatherMapSensor/setup.exe
Configuration
Once the application is installed, it will run in a terminal window (it’s a console application). It will ask you for the following information in order. Correct information will be saved, and you will not be asked again. If you need to reconfigure the sensor later, you need to delete the Data folder that is generated in the folder of the application, and restart it.
Note: If running intro trouble during the configuration, you can always stop the console application using CTRL-Z, and resume where you left off, by running the console application again. You will find the application in the Start menu, under the name OpenWeatherMapSensorConsole.
API parameters
First, you need to provide information on how to connect to the API:
Once these three parameters have been provided, the app will attempt to connect to the API and read data for the current location. If successful, the configuration will be saved, and you don’t have to enter it again. If not successful, you will be prompted to enter the information again.
XMPP parameters
The next step is to provide configuration for XMPP connectivity. The folllowing parameters have to be provided:
Once these parameters have been provided, the app will attempt to login to the XMPP network. If successful, parameters are saved, and you can continue. If not, you will be provided an opportunity to correct your entries.
Thing Registry
Next step is to provide locale-information for the Thing Registry. A Thing Registry is a service that allows the owner to find the device, and if the owner chooses to, also let other users find the device. The following parameters are optional, and are used when other users try to find devices of interest, based on location.
Ownership
Once the device has registered itself in the registry, it is time for you to claim ownership of the device. Ownership allows you to control who has access to the device, and what data they are permitted to read.
Ownership is claimed, by presenting the Thing Registry with exactly the same information as the device has presented to the Thing Registry. Apart from the information you’ve already entered, there are information about make and model, etc., as well as a secret key. To help you provide this information, the application presents you with a QR code, with all the information included. The QR-code is available in three different ways:
First, it is presented using block-characters, in the terminal window. If your terminal window supports block characters, you can simply scan the QR code from there.
The application also saves a
Sensor.iotdiscotext file in the installation folder. (You can find the installation folder, by simply clicking on the tab of the terminal window, and requesting to rename it.) Open this file in a text editor, and you’ll find the contents of the QR-code. If you’re a developer, you can paste this link manually into the app, to claim the device.There is also a
Sensor.iotdisco.urlfile saved in the installation folder. Click it to open a tab in your browser, showing a QR-code. Scan this QR code with your app, to claim the device.
Note: When claiming the device, you have the option to let the device be public. This does not mean everyone has access to the data in the device, or can control it. It just means anyone with access to the Thing Registry, is permitted to find it. If they want to read data from it, you, as an owner, will be asked if this is OK before any data can actually be read.
Connecting to device
Once the device has been claimed, you, or anyone else, can try to connect to it using the XMPP Address (JID) created when the application connected to the XMPP network. The format of the JID is UserName@Domain, where the Domain is the domain name (or host name) of the XMPP broker.
You connect to the device, by subscribing to presence of the device. At first, this request will be rejected by the device. At the same time as the request is rejected, a notification is sent to the owner, who can manually choose to accept, reject or ignore the request. Once accepted, your application will either automatically connect to the device, or you will have to manually subscribe to presence again. This second time, after the owner has accepted the request, the sensor app will accept the request. This does not mean you can read it yet however.
Reading device
Once you’re connected to the sensor, and can see it is online (i.e you have its full JID), you can request to read the sensor-data from it. As earlier, the first request will be rejected, if no formal approval has been given before. The first attempt, will generate a notification to the owner, who can choose how to handle this request. The owner can choose to deny access, or grant access, either fully, or partially (i.e. only to partial content). The decision can be based on your network identity, or based on other principles. Once granted access, you can try to read again, and this time, you will get access to the sensor data in the device.
Chat
The sensor app also supports chat. Once you’ve added the device to your contacts list, you can chat with it to read sensor data, or perform control actions. Try sending hi, or # to it, via chat, to see what happens.