The following is the summary of a workshop I held for the IT department in Danske Spil A/S.

First a few things to keep in mind before you start:

  • I’ve only been working with the Arduino for a limited period of time, so there could be errors in the guides – if you find any, please let me know!
  • The guides on this site are prototypes (accuracy, reliability, battery)
  • The prototypes are very basic examples. So you are expected to initially follow the guides, and then think out of the box… “where could you go from here”?
  • Double power is bad! Run either with USB power OR battery, not both! 🙂
  • Google is your friend – don’t hesitate to google connections, code examples, etc!

In order to get started, I’ll quickly go over a few words often used when dealing with Arduino projects.



Back when I was a kid working with electronics we had to solder stuff together in order to test a prototype, now some brilliant guy invented the “Breadboard”. A breadboard is a fantastic way of building prototypes. It’s basically just a board full of holes that are connected from the factory. By sticking components into the holes, you can connect them together to form prototypes.

So, meet the breadboard:


As you can see from the right side of the image, you have small metal connectors connecting all the holes in the first column from left together. In the same way, the second columns holes is connected together. This enables us to add plus to the first hole in the first column and minus to the second allowing us to have a number of holes to draw plus and minus from.

The middle section of the breadboard is connected together differently. Here, each row of holes are connected together.

Try out a few of the project on this site and you’ll soon learn how to use the breadboard.


Jumper cables

Jumper cables are cables that we use for connecting the holes. Image of Jumper wires can be seen below.


Connecting one end to one hole and another end to a different hole connects the two.


Dupont cables

Dupont cables are cables that we use for connecting Arduino modules together. One example is when we connect the Arduino to the USB adapter to upload programs to the Arduino. The image below shows a Male-female dupont cable.


You can get Dupont cables both as Male-male, Male-female and Female-female. They are usually more “stiff” than Jumper cables but the advantage is that they are glued together, so we can for instance split them so we have a set of 4 cables that are glued together. This can then be used for connecting a 4 pin module to the arduino or breadboard. By having them glued together its easier to see what cables go where as your project grows. The image below shows how a Dupont cable is used to connect the Arduino to the computer via USB.

Screenshot from 2017-01-06 19-53-07.png

So, now we’r ready to look at the Arduino itself. I more or less only use Arduino Pro Minis so this is what I’ll be focusing on in this post.


Arduino Pro Mini (5V / ATmega328)

You can find the Arduino Pro mini in many forms, both as 3.3V or as 5V. I primarily use 5V as that’s by far the easiest to work with. Most components use 5V or less, so by using the 5V Arduino, you can “just” add a resistor to your project if you are dealing with a component that can only handle less. If you were working with the 3.3V Arduino you would have to add a “boost converter” to go from 3.3 to 5V.

One disadvantage though, is that if you are working with projects where power consumption is key (for example battery driven projects), the 3.3V Arduino version uses less power, so dive in to this if you need it.

This is the Arduino I primarily use:

Screenshot from 2017-01-06 20-01-28.png

So, the Arduino Pro Mini has Digital ports working with values of either 0 or 1. These ports can be used for sensors that you basically read whether they are switched on or off, or turn on/off.

The analog ports have the advantage that you can read a value from them. So for instance you can add a plant soil moisture sensor and read not just if the plant is dry or wet, but a value that tells you just how dry it is. Clever!

Now, looking at the GND and VCC, these are the two minus and plus connections on the Arduino. VCC works with 5V so you can draw 5V from this when you have powered your Arduino via for example a USB connection as we’ll see later.

The RAW connection can be used for powering the Arduino from any 5-12V power source, so if you are running on say a 9V battery, this is where you connect the plus sign.

Finally, looking at the right side connections, you have a number of other pins that I wont go into details with. For now just know that we use them to connect the Arduino to the computer.

So, how do you connect the Arduino to your computer? See below…


Connecting to your computer

In order to connect the Arduino to the computer you need a CP2102 or similar. The image below shows the Arduino on the bottom left and the CP2102 on the top right.

Screenshot from 2017-01-06 20-09-31.png

Connect the CP2102 like shown above and it should be possible to upload programs to the Arduino from your computer. More on that later…

Note that there are many variations of the CP2102. Some modules has the choice of running either 3.3V or 5V. In that case, you should use the pin that matches the power of the Arduino you are using.

Make sure to get a device with the DTR pin – that makes everything easier.

TX and RX are transmitting and receiving pins used to communicate between the Arduino/CP2102.


Whats next?

So, my next post will be addressing most of the basic components you need when building the prototypes from this site…. Follow me!