Using Amazon Alexa to Control Custom IoT Gadgets

In part two of his article, Brian describes integrating custom IoT gadgets with Amazon Echo using emulation to receive spoken alarms. In part one, he used emulation and Arduino Cloud services as a middleman.

- Brian Millier

Part 2: Emulation and Spoken Alarms

In Part 1 of this article, I described two different methods of designing a custom IoT device that could easily be integrated with the Amazon Echo smart devices by making use of the Alexa speech recognition feature. One method involved the emulation of a commercial Alexa-compatible device, the Philip's Hue smart light bulbs. The second method used the Arduino Cloud service as a "middleman" between the custom IoT device and the Amazon Alexa cloud server.

In this article, I'll describe another custom IoT device that uses the emulation method. To conclude the series, I'll describe an IoT device that can notify your Echo device of an alarm condition, allowing you to receive spoken warnings, and notifications to your cellphone or tablet.

TRICKY THERMOSTAT

I became very interested in electronics when I was about 10 years old. I don't recall how I justified it, but, as a teenager, I remember taking a thermostat off the wall at home, to see how it worked. Figure 1 shows one of these old round Honeywell thermostats, with its cover removed.

How it operated was fairly obvious: There was a bimetallic strip wound in a spiral shape.

At one end of it was a glass enclosed mercury switch, oriented horizontally. Turning the temperature-setting dial must have adjusted the other end of the spiral, I believe. As the room temperature changed, the spiral would wind/unwind and the mercury switch would tilt, opening and closing the switch contacts.