Connecting to the Internet

Talk² is all about communication and adding Internet connectivity to your project can easily bring it to the next level! Despite the fact that you can find a couple of alternatives to it, we would like to present our prefered way.

On this post we’ll briefly check the common ways of connecting an Arduino to the Internet, evaluate the Pros and Cons. After we’ll present the Talk² approach to this problem, explaining concepts and queueing techniques to build a much more robust and flexible solution.

The popular options

After some research we easily concluded that the most popular way people are connecting their Arduino to the Internet is by using a direct Ethernet connection. Some cases using shields or expansion modules, others by simply relying on the build-in Ethernet capabilities of the board/MCU.

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

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