Blog moved

 

All posts will be moved there in close future.

Comments

Post a Comment

Popular posts from this blog

LERP, NLERP and SLERP

Image
WHAT IS THAT AND WHY DO YOU NEED THIS? Whenever you've got 2 numbers and you want something between them, you want some kind of interpolation. And the same in quaternions - you have to quaternions that describe the same no one is 100% correct but 100% incorrect either, so you want a quaternion that is a combination of these two. So you can use the simplest idea of combining two numbers: \[\mathbf{q}_{3}=\alpha \mathbf{q}_{1} +(1-\alpha)\mathbf{q}_{2} \label{eq:LERP}\] this is LERP ( linear interpolation ) but since, for orientation porpuse quaternion need to have norm of 1, after this interpolation you need to normalize result: \[\mathbf{q}_{3}=norm(\alpha \mathbf{q}_{1} +(1-\alpha)\mathbf{q}_{2}) \label{eq:NLERP}\] and that is NLERP ( normalized linear interpolation ) . Now, how these methods could be interpreted, and what are the consequences in real applications?  If we imagine a circle with a radius of 1 which is going across quaternions that we want to inter...
Read more

Filters - Theory

Image
 Filters  In this post, I want to present the theory needed for digital filter design. Firstly, a quick description of mainly used filters in the continuous domain - I want to give you some intuition in interpreting the transform functions. Next, I will present practical discretization from the '$s$' domain into the '$z$' (discrete time). Finally, a difference equation will be provided which can be directly programmed on any microprocessor. In a future post, I will show the possible implementation of described filters. In essence, the filter should block undesirable frequencies and let others pass through without distortion. For our applications, we can divide filters into 4 main categories: Low-pass filters High-pass filters Band-pass filters Notch filters Low-pass filter As the name suggests this filter allows low frequencies to pass and suppress high ones. The simplest LPF is a system with one pole: \begin{gather}H(s)=\frac{\omega_{0}}{s+\omega_{0}}\end{gather} A typ...
Read more

How to develop STM32 with VScode? part 2/2

Image
  So far, everything was working only if you were using the same MCU as mine - STM32F405RGT. Since, arguably, not everybody is programming drones on this exact MCU, in this post I will show how to set up a project from scratch and along this way reveal a bit of the mystery of how everything works and what was the purpose of some files from a previous post. Luckily this will be the last part of this complicated process and ideally, after that, you should be able to develop any STM32-based board. Create a project structure Open the folder where you want your project and create new folders: Src , Drivers , bin , build , link . I keep the same folder structure among all projects so that I can just copy an existing one and change only MCU-specific parts. Of course, you can have different folder structures, but be aware of that and make suitable adjustments throughout this post.   Add files The next step is downloading and adding all essentia...
Read more