OpenWeatherMap API example

The source files located in this folder illustrate the use of a HTTP function block in order to get weather data via OpenWeatherMap API.

Block HTTP is set up to receive data from OpenWeatherMap API. It is possible to get data with current weather condition all over the world, 5 day / 16 day weather forecast for specified cities / coordinates and many other weather data. The example shows how to get current weather data in Pilsen, CZE via JSON request. JSON string is parsed afterwards using blocks PJROCT (real) and PJSOCT (string).

Note

This example can be easily modified for other data providers such as WeatherUnderground API (http://www.wunderground.com/weather/api) The Dark Sky Forecast API (https://developer.forecast.io/) or any other API using JSON formatting.

Timing of the project

The algorithm runs each 500 milliseconds (0.5 s). See the EXEC function block,
tick x ntick0 = 0.1 x 5 = 0.5 s

Prerequisites

• REXYGEN Runtime Core must be installed and running on the target device.
• Registration (free) at OpenWeatherMap in order to get unique API ID.

Running the example

• The *exec.mdl file is the project main file.
• Open it with REXYGEN Studio.
• Specify your unique OpenWeatherMap API ID into CNS_API:ID:scv. It will concatenate together with parameter "url" of "HTTP" block whole GET request: http://api.openweathermap.org/data/2.5/weather?q=Pilsen&units=metric&appid=your_API_ID
• Compile and download it to the target device.
• Change CNB_TRIGGER_GET to ON and ispect outputs of PJROCT and PJSOCT blocks to see received and parsed data.

Documentation

• Press F1 for help on the selected function block in the REXYGEN Studio.
• OpenWeatherMap API documentation
• REXYGEN Studio User Guide
• Complete documentation of REXYGEN

Additional information

• Visit the REXYGEN webpage for more information about the example projects and developing advanced automation and control solutions using REXYGEN.