About this page

Hello there, my name is Daniel and welcome to my blog!

The blog posts here are from my notes or small projects, I focus mostly on programming with C++. I'll try to do my best to publish quality content and references here on the ComputerEngineerStudent. Though, the whole concept behind the blog is for me to go through some of the old notes and projects I've been through. Hopefully someone else could also get an advantage from reading here.

Popular posts from this blog

Minimum Spanning Trees (MST)

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Let's imagine an undirected graph with weighted edges. From this graph, the spanning tree wil be a tree that maps all the vertices. In other words, the tree seen above will be G = (V, E) = (4, 5) and the spanning tree must be at least S = (4, 3). Let us visualize us this down below. Here we will have S = (4, 3) marked with green, which will be our spanning tree. As we can see, it covers all the vertices in the tree. However, it doesn't cover all the vertices in regards to the weighted edges. This S tree will have the sum of 4 + 5 + 2 = 11. Now when it comes to minimal spanning trees, we have to care about the weighted edges in the graph. Let's find the minimal spanning tree of the G graph above. Let's call this subgraph for S2 = (4, 3). In this subgraph we will see that the sum will be equal to 4 + 1 +2 = 7 and that it covers all the vertices. Since it has the smallest sum out of all the spanning trees you can make over graph G, it will be the minimal sp...
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Vigenère cipher encryption with C++

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Vigenère cipher is a substitution cipher that uses a 26 x 26 alphabetic table to either encrypt or decrypt. For example, say we wanted to encrypt the plaintext: "DAY" Then we would first pick an arbitrary keyword for the letter, let's go with: "SEE" From there on out, we would use the plaintext on the columns and keyword on the rows on the 26 x 26 table and then substitute. Ultimately, we would see that the plaintext combined with the keyword turns into: "VEC" Which will be our final encrypted text. An illustration of this can be seen visually as: Now, let's move over to the C++ program and start with main.cpp. main.cpp #include "Vigenere.h" Vigenere * vigenere = nullptr; int main () { vigenere = new Vigenere(); while (vigenere -> isRunning()) { vigenere -> showMenu(); vigenere -> handleEvents(); } return 0 ; } In this case, we're simply creating a new instance of a Vigenere object that we're g...
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Simple Arduino PIN lock with LCD Display

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I thought it would be fun to build something that looked like a smart lock for a door. With an Arduino Uno, three buttons being 1, 2 and 3 along with a buzzer, some LED diodes and a microservo I was able to make a simple mechanism that can both grant- and deny access. The servo will rotate on a valid PIN and keep an angle for X seconds (See gif underneath). Furthermore, if the PIN code is incorrect the servo won't rotate. Here's a gif of the system in action. Starting out with recreating the project I will be using TinkerCad to illustrate some of the parts. We can start out with the attachment of the three buttons to a breadboard, along with some LED diodes to indicate a button being pressed. From there we can add the buzzer (Piezo speaker in this image) and one more LED diode which will both activate when the PIN code is correct. This is when the system should grant access and the servo rotate. Now we can connect the servo to the breadboard. ...
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