News Flash Headlines
This project will pull a fresh headline from News API and display it to the OLED screen. News API is a news aggregator that returns headlines from a variety of news sources as JSON data.
Skill Level: Beginner
Time Required: 20 minutes
The project will use a Python script to call the News API
/articles endpoint for headline data.
The complete project code can be found in Onion’s
oled-news-flash repo on GitHub.
Here’s how to get your own headlines screen running on your Omega!
1. Prepare your Ingredients
You’ll have to have an Omega2 ready to go, complete the First Time Setup Guide to connect your Omega to WiFi and update to the latest firmware.
Once that’s done, plug in your OLED Expansion:
2. Install Python
Connect to the Omega’s command line and install Python and some additional packages we need:
opkg update opkg install python-light python-urllib3 pyOledExp
python-urllib3 package will allow us to make HTTP requests in Python, while the
pyOledExp package gives us control of the OLED Expansion.
3. Download the Project Code
All the code from the project can be found in the
oled-news-flash repo on GitHub.
This project only has two files, so you can download it directly to your Omega without much hassle.
mkdir /root/oled-news-flash cd /root/oled-news-flash wget https://raw.githubusercontent.com/OnionIoT/oled-news-flash/master/oledNewsFlash.py wget https://raw.githubusercontent.com/OnionIoT/oled-news-flash/master/config.json
If you’d like to use git instead, install Git on your Omega, navigate to the
/rootdirectory, and clone the GitHub repo:
cd /root git clone https://github.com/OnionIoT/oled-news-flash.git
4. Obtain a News API Key
We need an API key in order to access the News API endpoints. The simplest way is to create an account which will give us access to the News API key generator.
Register at https://newsapi.org/register and copy your API Key:
config.jsonand paste the API key generated as the
X-API-KEYvalue - replacing
your api key here:
5. Choose Your Source
News API gets headlines from 70 different news sources. We’ve set the default source to Reuters, but you can change easily change the source of your headlines. Head over to News API’s sources page and pick your source:
config.json and copy the text under any source you wish as the value for
source - replacing
6. Run it!
On your Omega’s command line, run the following:
And you should see the latest news headline on your OLED screen.
7. And Beyond
Now we can automate this script with
cron to keep the headlines updated on the OLED screen.
crontab -e to add a task to the
cron daemon, it will open a file in vi, enter in the following:
*/15 * * * * python /root/oled-news-flash/oledNewsFlash.py #
This assumes that your project code is located in
/root/oled-news-flash/- if it’s not, don’t forget to change the directory!
Now, we’ll restart
cron to update it with our new task:
And the code will run once every 15 minutes, updating the OLED screen with the latest headline.
Check out the Omega documentation for more info on using
Many web sites and services provide Application Programming Interfaces (API) to allow others to call on the data they provide without a whole webpage to bog it down.
Calling an API is all about knowing what the API needs, and how to deliver that data.
To contact any API, we need to know at least two major things:
- URL - the address we need to look up
- Method - what method the URL accepts, and what do they do
For this project, our URL is
https://newsapi.org/v1/articles. The URL has two bits to it, first is the the actual API’s location -
newsapi.org/v1/. The second is the endpoint, kind of like a specific apartment number of the address. Here it’s
Together, they’re often referred as an endpoint of the API.
News API has a
/sourcesendpoint as well which provide different services when called.
Now that we have our endpoint, we need know how to request data from it.
When sending a request, it must be made with a request method to let the server know what we need at a broad level from the endpoint.
HTTP supports at least nine different request methods to accommodate different needs. The most common ones are ‘GET’, ‘POST’, and ‘DELETE’.
Logically, to get data from the
/articles endpoint, we need to send it a ‘GET’ request.
Parameters, Headers and Bodies
Often, APIs provide personalized data - calendars, emails, and other user-specific data. To implement this kind of interaction, requests are sent with parameters, headers and possibly a body for ‘POST’ requests.
Parameters are strings that get appended to the request URL with details about our request. This is the most basic way of communicating additional information to the server.
In this case, the
sortByvalues are sent to the server through URL parameters. Meaning, the request from the news flash code is to the following URL:
The API key is a way to identify and authenticate a user of the service, allowing APIs to pull up user-specific data. For an API serving general information like News API, an API key is mostly useful in identifying the user’s level of access.
Generally, the API key is passed through the HTTP request’s header - a list of key-value pairs that is sent with our request. What goes in the header depends on the particular API being used. The documentation should always specify what kind of things should be put in the header to correctly get information.
In the news flash code, the headers only contain the
The body is typically a JSON list of key-value pairs used to store content for ‘POST’ requests. Again, the specifics of the body depends on what the API needs.