WinCoder Blog

Spark Core + DS18B20 + Azure Event Hubs = IoT Hot Tub / Pool Monitor



Summer is here in Houston and there is no better time to get in the water to cool off or warm up.  I am particularly fond of the latter, especially with a good group of friends, food, and refreshments.  The problem is,  it can be hard to tell when the hot tub is ready without actually getting in or looking at a temperature gauge.

Enter Spark Core, a Wi-Fi enabled micro-controller that can be programmed remotely from  a web-based IDE.  I absolutely love this device for ease of programming, portability, and resilience.  Let me reiterate on resilience.  I have successfully ran my Spark Core devices for weeks at a time with zero downtime.  I think these things are pretty much impervious to breakdown so far.  To give a visual output of the temperature, I added a Spark Button device to glow a specific color in relation to the current reading.

I have had alot of fun getting this device to work with the ConnectTheDots project from MSOpenTech.  This project allows for connecting a variety of sensors either directly or through a gateway, into Azure Event Hubs for real-time Streaming Analytics processing.  The results are then displayed in an Azure Web Portal.  I absolutely love this project for it’s ability to walkthrough a serious end-to-end IoT solution and have enjoyed both contributing and delivering IoT Dev Camps based on the project.

Build your Own!

The hot tub monitor solution leverages my previous post on “Sending messages to Azure Event Hub with Spark over AMS API Proxy“.  All code has been contributed to the ConnectTheDots project.  To replicate, simply follow the instructions for setting up the Spark+DS18B20 documentaion and insert into your pool or Hot Tub!  The only modification I made was to use a portable 5v battery source which could be greatly improved using a 5v solar cell.


He’s heating up!


He’s on FIRE!








You may be wondering, is this really useful?  I actually ended up using the device over the weekend, and was happy to see the ring turn red indicating to guests that Hot Tub was in fact ready!  This no doubt got a lot of questions and spawned some discussion on improving the Hot Tub experience further.  Stay tuned for an update on what we plan to implement.  A few hints, it involves a Microsoft Band, Windows Phone App, raspberry Pi, and audio responsive LED driver!


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