Pervasive Reporting

This project was prompted by the management of embedXcode. Is the website up and running? Do downloads perform smoothly? Are there tickets to answer?

How to deal in a timely manner to all those events? Up to now, I had to turn a computer on, log in and check manually different sites to check each possible event. Very time consuming. 

​So the idea is to have the information always available, and to check it visually.

General 

Because each metric is provided by a different supplier, the first step is to gather the information from all the relevant websites. 

Some websites provide an API to get the information, others don't. For example, the request for getting the number of open tickets is listed on the right, based on the Freshdesk API.

​Converting a URL request into a POST request isn't always easy, especially when authorisation is required.

Instead of interrogating each external supplier, a page on my website gathers all the information and provides a unique compact JSON string with all the answers.
 

    









					
									

		
	





Micro-Controller




	

		
			

				
					
						


The micro-controller connects to the dedicated page and retrieve the JSON string with all the metrics. For simplicity, I'm using WiFi with the CC3200 LaunchPad. 

LEDs are turned on and off accordingly. For example, yellow reports an download error, red an open ticket (as shown on the right).

I like this qualitative approach. Total cost of this solution is USD 30 for the CC3200 LaunchPad. 



					
										
					
						




					
							

		
	






	

		
			

				
					
						


For a more compact form-factor and minimalistic design, I tried the Particle Photon with one single RGB LED.

The single RGB LED displays the colour of the most important item, for example red goes over yellow for ticket being more important than download error.

This solution is even easier to carry with a total cost of USD19, despite the lack of a valid off-line IDE.




					
										
					
						




					
							

		
	






	

		
			

				
					
						


For a more quantitate approach, I'm using a e-paper screen to display the different metrics.

I'm leveraging the three-colour e-paper display from Pervasive Displays to display errors and tickets white-on-red for better readability. 

Sure, WiFi isn't the best technology for a low-power solution, but BLE or sub-1 GHz would require a local hub to get the data from. The CC3200 LaunchPad includes 256 kB of SRAM, making the perfect solution for hosting the frame buffers required by large e-paper screens. 

The e-Paper Pervasive Display BoosterPack and screen should be added to the CC3200 LaunchPad mentioned in the previous solution. 



					
										
					
						




					
							

		
	





Nano-Computer




	

		
			

				
					
						


If a local hub is needed to gather the metrics from Internet and dispatch them locally through BLE or sub-1 GHz, why not to display the data right right on the hub?

​The Raspberry Pi Zero Wireless is compact, very affordable and expandable with hats. The Sense Hat features a 8x8 RGB LED matrix.

Even better, all the code for retrieving and displaying the metrics is carried out using Node-RED. The project contains three flows:
  • The first flow (shown right) sends the HTTP requests and gathers the responses.
  • A second flow displays the responses on a dashboard (shown on the top of the page).
  • A third flow displays the response on the 8x8 RGB LED matrix (shown below).
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The higher the values, the higher and thus the brighter the bars on the 8x8 RGB LED matrix. This is a nice balance between the two previous approaches, quantitative and qualitative.

Total cost of this solution is USD 45, with Raspberry Pi Zero Wireless at USD 10 and Sense Hat at USD 30. Hats with 8 RGB LEDs are available at a fraction of that cost.



					
										
					
						




					
							

		
	





Conclusion




	

		
			

				
					
						


As always, there are many solutions instead of a single one, and each one comes with its pros and cons.

Now, I no longer need to power my computer on and check those metrics manually. All the answers are there, ready right under my eyes.