Low Power Budget

One of the biggest challenge for the Internet of Things, especially for those devices using RF communication, is the power consumption. In many situations it’s normal to expect the wireless equipment to have their own source of power, instead of relying on an AC-DC power supply connected to the wall outlet. In the IoT world there is a real demand for 100% wireless devices, powered by battery or any kind of power harvesting.

The first question you need to answer yourself before start building battery powered circuits is: For how long I wish the device to run on new batteries? One day, a whole week, maybe a year? Or just be brave and say 2 decades.

On this post we’ll talk about the low power world, how you can plan, design and implement circuits that can work for years on a pair of wide available AA batteries. We’ll also present the common trade-off and techniques necessary to reduce power consumption, as well discuss how RF communication can be implemented with minimal power requirements.

This can be a very complex and long topic and we’ll try to keep it as much practical and simple as possible. Bear in mind that we won’t offer a ready-to-use, kind of copy and paste code. The whole idea is to be broader and educate how to identify and solve common problems.

Talking about Power

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Wireless Link

This post is a continuation of The Talk² Protocol post, which explained some basics about the Talk² protocol as well basic details about the Wired link.

One more time is important to highlight that the Talk² protocol is independent of the hardware it runs on. For our own boards designs we’ve made some decision, defining which technologies and hardware to use based on our experience. Remember that you’re free to implement the same protocol rules on top of any other media.

RF: Not so simple

A wireless link sounds much simpler than a wired connection. There’s no cables laying around, no mess and all works. But in reality, from an engineering point of view, it’s exactly the opposite. Wireless or radio-frequency (RF) links are much more susceptible to interference, reliability, privacy issues and even local government regulations. In an attempt to simplify our decision to which hardware should be used, we evaluate the following requirements: frequency, cost and features.

Frequency: ISM Band

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