Arduino is a programmable board with digital and analog inputs and outputs, whose low cost makes it ideal for getting started in automation or for small domestic projects in electronics and robotics.
This means we have a small “automaton”, capable of receiving information from the environment (sensors) and performing actions (actuators, motors…), according to a program we load from a computer, and which it can execute autonomously.
To give you an idea, until shortly before Arduino appeared, commercial/industrial automata with similar capacity cost several hundred euros.
This type of automaton is used to interact with and control all kinds of systems, from building installations (HVAC, pumping), industrial installations, vehicles, robots… any physical system that needs to be controlled electronically.
Arduino is an excellent platform for practice and learning. Both for programming and electronics, as well as for an introduction to automation and robotics (and with it, mechanics, hydraulics).
Furthermore, it will bring you hours and hours of fun working on your robotics and electronics projects (for less than the cost of a night out), which is always great.
To get started with Arduino, logically, the first thing is to buy one. That’s why we are going to look at the different models available.
If you want to start with an electronic components kit, you might be interested in the post
Which Arduino model should I buy?
There are many Arduino models available, which can be a bit confusing for new users. When choosing, it’s normal to focus on the number of inputs and outputs it has, especially the analog ones since they are usually what restrict our project.
In the following table, you can see the most common Arduino models, with their most important characteristics and a reference price when buying them on eBay or AliExpress from Chinese international sellers.
| Model | Digital I/O | Analog Inputs | PWM Outputs | UART | Memory | Price |
|---|---|---|---|---|---|---|
| Uno r3 | 16 | 6 | 6 | 1 | 32kb | 7.5€ |
| Leonardo | 20 | 12 | 7 | 1 | 32kb | 10€ |
| Mega r3 | 54 | 16 | 14 | 4 | 256kb | 12.5€ |
| Mini 05 | 14 | 6 | 8 | 1 | 32kb | 2.5€ |
You have a complete list of the different models and revisions at https://es.wikipedia.org/wiki/Arduino.
It is most common to start with an Arduino UNO r3. This is the most standard model and is the board you will use regularly. For certain large projects that require handling a significant number of motors or servo motors (robots, CNC machines, 3D printers), it may be necessary to move to a model with a greater number of outputs, especially analog ones. In that case, it is normal to use an Arduino MEGA r3.
On the other hand, the Mini 05 model is for advanced users. It is a board for just 2.5€ and a really small size, designed for final applications, meaning when you are going to leave the board permanently connected (and therefore you are going to “lose” it). It comes without connection headers, you have to solder them, and to program it you need a USB FTDI adapter that costs 3.5€. At expert levels, this is practically the only board model you will use because, in case you need a large number of inputs or outputs, it is more economical to form a network of 3 or 4 Mini boards, and you get a capacity superior to a MEGA.
Therefore, final recommendation. Buy an Arduino UNO, which will be your standard development board. When you become advanced, buy one or two Arduino Minis, along with the programmer. And only for specific projects where the UNO falls short, and if you don’t want to complicate your life making networks of Arduino Minis, or if you need to use the additional serial ports, you can use a MEGA.
Only for the domestic sector?
Arduino is flexible and reliable. So, why did we say for domestic projects? Why not in commercial or industrial applications? It’s a good debate.
It’s something that might tempt you at some point. In fact, we know that people release commercial products that are based on Arduino. In principle, it’s most likely that everything works very well.
However, if one day you have to control (for example) the HVAC of a sports center, where just the chiller costs 250,000€… installing a 15-euro controller will seem reckless.
In that case, you will probably prefer to install a general-purpose automaton costing 500 to 1000€, which offers you a certificate and a guarantee for your peace of mind, and to protect your reputation (though everyone has their own professional criteria).
This is why it is usually associated with the domestic sector. But, the good news is that everything you have learned about electronics, automation, programming, and telecommunications, you will be able to apply directly and easily if you have to use a more expensive automaton.
Because, more or less, the electrons move the same (in fact, they move exactly the same) and things are programmed more or less the same.
Now that the introductions are done, in the next tutorial we will see how to install the Arduino development environment, to start developing.
Update 24/04/2015: Time passes, and prices change. I’m not going to keep updating the prices (because I wouldn’t do anything else all day 😆). But well, things are similar now, but cheaper.
