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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The Talk² Protocol

For any kind of communication to happens it’s necessary to define some protocol, a well defined set of rules known by all parts involved in the conversation. Talk² is not here to propose a specification for a new protocol, instead we are presenting some guide lines and to assist you developing your ideas.

On this post we’ll be talking a little bit about the Protocol used on Talk², which technologies we chose and why we’ve decided it.

Talk² Frame

One thing to keep in mind is that Talk² does not restrict you to any physical media or lower level protocol, instead it provides you a simple frame format. This means the only rule you need to follow is to respect the message format below:

Field Length (bits) Short Description
id 29 Message Identification
ext 1 Message Id format
rtr 1 Remote transmission request
dlc 4 Data length, or payload size
data 64 Transmitted data, up to 8 bytes

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Meet Talk²


Say hello to Talk², or Talk-Two or Talk-Square!

Today is our first post and we’ll explain a bit about this project. Before starting, feel free to follow us and leave you comments or suggestion. We’ll try to keep all details about this project as much up-to-date as we can, as well reply to any question you might have.

First come first: What is Talk² ?

In a sentence: Talk² is a microcontroller development solution with build-in communication capabilities. But in reality it takes a bit more than that to explain all the features and the problems it tries to solve.

You may noticed, we used the term development solution instead of development board, that’s because Talk² is designed to be a platform independent solution. In the real life it means that you’ll be able to make your Arduino project talk with a Raspberry Pi using wire or wireless communication. Better than that, you can reliably send and receive messages to your MCU from the Internet, which can be an AVR or ARM.

Solution Overview

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