Vibrations All Around Us 7: Fourier Transform and Spectrogram

Introduction Welcome back to Vibrations All Around Us! A blog series investigating the Digital Signal Processing (DSP) algorithms used to detect, measure, and extract meaning from the vibrations happening around us. This is an important post as we will be introducing the fundamentals of Spectral analysis, also known as the Frequency Domain, and one of the most important algorithms in engineering: the Fast Fourier Transform (FFT). Frequency Vs. Time Domain In the previous blogs, we looked at signal intensity (acceleration magnitude) with respect to the time that this signal intensity occurred at. It’s also possible for us to observe signal…

Vibrations All Around Us 6: Crude Pedometer

In this blog post, we will be building a Crude Pedometer using the Nicla Sense ME. By the end of this blog post you’ll be able to measure how many steps you’ve taken with the Nicla on your shoe and how far you traveled, emulating a wearable device. For this lab I’ll simply be sticking the Nicla on top of my shoe as shown below. It should be as rigidly attached to your shoe as possible so it picks up on the impact of your shoe as it strikes the floor on each step To get some inspiration for how…

Vibrations All Around Us 5: Activity Score

Introduction Welcome back to Vibrations All Around Us! In this blog post, we are going to be building an algorithm for a wearable device to rank your activity levels throughout the day. Let’s get into it. When we think of vibrations, we typically think of high frequency movement occurring over a short period of time, but we can also observe vibrations over the course of minutes or hours. When it comes to looking at activity levels, we are interested in vibrations that occur over a very long period of time. I’m going to hold the Nicla in my hand to…

Vibrations All Around Us 4: Crude Leveler

Introduction Welcome back to the Vibrations All Around Us blog series, where we will be learning about fundamental signal analysis algorithms and using them for real-world applications. In this blog post, we will develop a crude leveler. The goal of this lab is to be able to move the Nicla chip around in space, and get feedback once the chip is within 1° of level. We will use the fact that the accelerometer is sensitive to gravity, and align the Z-axis of the accelerometer with gravity. Let’s get into it. Very Crude Leveler At it’s core, to make a leveler…

Vibrations All Around Us 3: Nyquist Theorem and Other Definitions

Introduction Before we get started with utilizing our hardware to perform vibration signal analysis, we need to understand some key definitions from the world of Digital Signal Processing (DSP). In this post, we’ll be examining the difference between the Continuous and Discrete Space, Nyquist Theorem, Real-Time vs. Batching Techniques, and Causal Vs. Non-Causal Systems. Be sure to start at the beginning if you have just found this blog series! Continuous Vs. Discrete Space When working with digital measurement devices, we are limited to gathering information in “discrete time”, that is, we can only take a finite number of measurements within…

Vibrations All Around Us 2: Tools Setup

Introduction In this post of the Vibrations All Around Us blog series, we will be discussing the setup of the Nicla Sense ME microcontroller that will be used for measuring vibrations in all of the future labs in this series. For those of you completing the labs with us, this will be an important lab for you as this is the tool we will use for all of the following experiments. If you are just finding this page, be sure to start from the beginning introduction to the series. Getting Started with the Nicla Sense ME To test out the…