We want to build an experience for our customers that is as simple and cost effective as possible. Currently (in North America) we don’t have a well defined low power (and ideally low cost) wireless network for communicating with the Internet. Yes, LoRa is on the way, as is LTE Cat.M1 or Cat.NB1, but they aren’t here yet. And when they do arrive, what will they cost?
We’ve also made the decision not to require the installation of an additional bridge device that transfers some simple low power RF protocol to the internet via ethernet, WiFi, or LTE. This is a common solution, but personally I don’t like the customers’ setup experience, nor do I want to design and manage 2 separate hardware devices.
Technically, a smartphone can function as a Bluetooth bridge, but for our application a dedicated smartphone isn’t going to be present at all times. That really just leaves us with LTE and WiFi. While LTE would be a nicer solution, it’s currently far too expensive (and overkill) for our application. So, by process of elimination we’re left with WiFi.
WiFi Has Its Advantages
WiFi is available almost everywhere, and is standardized across the entire planet. Due to its ubiquity, we can now purchase fully operational, fully certified modules for under $2 USD. This drastically reduces development time and cost. The full WiFi stack, antenna design and tuning, and regulatory testing in all regions is included in that price. The availability of these Chinese designed WiFi modules is in part what has made low cost WiFi based IoT devices possible.
However, we are still faced with the high power and high energy demands of WiFi. This is where most of our initial hardware investigations and prototyping will be directed. How can we take advantage of the ubiquity, and low cost of WiFi and still offer battery life measured in years using a CR2032 coin cell? Honestly, I don’t know yet. That’s just one of the challenges we hope to solve with this product.