Is That Stove BurnerOn?

Introduction

A while back Monica Houston from Hackster asked me to put together an example application which used Azure Sphere secured MCU technology to demonstrate some of the capabilities of this platform for an upcoming Hackster Webinar for our Secure Everything Design Contest launch:

http://avnet.me/mt3620-kit-SE

Not being much of the creative type myself, Monica threw out a few creative ideas and I immediately latched onto the idea of doing an example application that could detect flames. Such a project would not only be interesting for me to work on, but also practical for my own home where I have several chefs (some of them are still young) working in the kitchen constantly.

I set out to work to create this BurnerOn example application on the Avnet Azure Sphere Starter Kit in order to warn people when a flame is detected nearby. Ultimately, this secured, IoT-enabled smart sensor detects the point at which the flame erupts, rather than waiting for your house to catch on fire to generate smoke which is detected by traditional smoke detectors.

The benefit to this early-warning approach is that once the flame is detected, a visual and audio alarm are triggered immediately to warn occupants of the potential hazard. If responded to in time, well before any significant damage to the property has occurred, this could potentially save costly home damage arising from kitchen masterpieces turned into disaster.

Modifying Azure Sphere Starter Kit

Very few physical modifications were made to the Avnet Sphere Starter Kit board for this project. Thanks to the fact that 2 MikroElectronika Click sites are provided on this board, I only needed to solder in a few expansion headers. I talked to the hardware designer about this and it turns out the J7 and J10 socket connectors are not populated at the factory in order to save some cost on the PCB assembly and keep the resale price low for everyone. Not super convenient for this project, but by far not a showstopper either! The connectors I use are only suggested for convenience, if you are comfortable soldering wires directly to your board then you can skip this section.

Using your soldering iron, solder the Female Header 4 Postion 1 Row (0.1") from Samtec to the open pads at PCB site J7.

Then add one of the TE Connectivity Wire-To-Board Terminal Block, 2.54 mm, 2 Positions connectors to PCB site J10. Be sure to make sure the beveled guided sides are facing outward which will help make it easy to run the 5V supply wires into the terminals later on.

Add the OLED Display

Plug the 0.96-Inch OLED 64x128 I2C Display Module to the Sphere Starter Kit by inserting the 4-pin connector into the header added to site J7.

Connect the DC/DC Converter to Supply Wires

Using a soldering iron, remove the VIN pin from the MPS DC/DC Power Supply, 6.5-36V Input, 5V Out, 2A module and solder the Male-Header 2 Position 1 Row (2.54mm) connector to VIN and GND pin pads.

Next, solder at least 150mm of 20 AWG wire from the two header pins to your 12V power supply or simply run them to banana jacks for convenient connections.

Your DC/DC power converter input supply cabling should look similar to this when you are finished:

Wiring Each Component Together

Connect the two Click modules to their respective Click sites. The Flame Click is connected to Click site 1 using J1 and J2 sockets. The Relay Click is connected to Click site 2 using J3 and J4 sockets. Be very careful to align the Click modules with the connectors correctly. All pins should be fully inserted into the socket connectors on the Sphere Starter Kit board.

Wire the MPS DC/DC Power Supply, 6.5-36V Input, 5V Out, 2A module directly into the screw terminal added at Sphere Starter Kit PCB site J10. Be sure to orient the DC/DC converter with the large ground pad facing up, this will ensure the VO and GND pins are in proper alignment with the 5V + and - pins respectively. Gently tighten the small screws with an M1 sized screwdriver.

Following the provided wiring diagram, connect the remaining wires together on this system. For any other 12V connections (such as the audio alarm and visual alarm) I would highly recommend using 12 AWG or 14 AWG sized wire.

I used banana connectors which made it easy to connect and disconnect equipment as I did a final system check to make sure individual components are fully functioning as expected. If you have another connection system you prefer for wires, please use what you are comfortable with. Some folks even prefer direct connections to get everything working first time around.

Connecting to the Sphere Starter Kit

The Sphere Starter Kit must be claimed to your tenant and placed in debug mode before you can load code to it. If your are not familiar with either of these, please refer to this blog article that Brian Willess put together which describes this process in further detail:

http://avnet.me/mt3620-kit-OOB-ref-design-blog

Connecting to the Cloud

This example can be connected to the Cloud easily using Microsoft IoT Central SaaS offering. I did my project code while following the instructions in the blog Brian Willess wrote on this topic over at Element14:

http://avnet.me/mt3620-kit-OOB-ref-design-blog-p3

Conclusion

For relatively low cost, you can utilize the security of the Azure Sphere architecture for your next IoT design.

This BurnerOn project is just one of many possible hardware combinations you could use. As of the time I am writing up this project, there are over 700 different Click modules out there which gives you over 490, 000 different combinations of hardware you could potentially come up with. My colleague Jim Flynn put together some example Click libraries which can be leveraged for your next project so be sure to check out the Element14 Blog article he wrote on this topic:

http://avnet.me/mt3620-click

With all that being said, I wish you good luck, have fun hacking, and be sure to practice safe HEX everyone!