https://charleslabs.fr Charles Grassin electronics and code projects articles. en-us CC-BY Charles Grassin https://charleslabs.fr/favicon-32x32.png https://charleslabs.fr BioSignals is an open-hardware bio-sensing acquisition board designed for capturing bio-potential signals such as EEG, ECG, and EMG. With up to 8 channels, high-performance analog interfaces, and multiple data output options including USB, Bluetooth, and microSD, BioSignals is a versatile and low-cost solution suitable for a wide range of research applications. This article provides an overview of the system's features, design, and potential use cases. elec https://charleslabs.fr/en/project-BioSignals+-+Multi-Channel+Bio-Sensing+Board https://charleslabs.fr/en/project-BioSignals+-+Multi-Channel+Bio-Sensing+Board Sat, 01 Apr 2023 00:00:00 +0200 This passive RF differential probe is intended for the measurements of RF circuits within the frequency range of 500 MHz to 6 GHz. It is ideal for in-circuit measurements where no test port is available and has minimum effect on the DUT while being inexpensive to produce. This article goes over the design, performance, simulation and measurements of the device. elec https://charleslabs.fr/en/project-RF+Passive+Differential+Probe https://charleslabs.fr/en/project-RF+Passive+Differential+Probe Fri, 10 Mar 2023 00:00:00 +0100 KiCad is a powerful open-source electronics design automation tool. Plugins can improve its functionality and streamline the design process. This article focuses on two plugins I developed to enhance KiCad: Auto Silkscreen Placer, which automatically moves silkscreen part designators to readable locations, and Pinout Generator, which exports component pinouts to various formats, including C/C++ code, CSV, and FPGA constraints files. info https://charleslabs.fr/en/project-KiCad+Plugin+Development https://charleslabs.fr/en/project-KiCad+Plugin+Development Mon, 27 Feb 2023 00:00:00 +0100 Microfluidics is an area of research based on the manipulation of small fluid volumes on the order of microliters or nanoliters. I designed µDropplet, an inexpensive plateform with an 8×8 array of electrodes driven by a high voltage to experiment with various microfluidics techniques and materials. This article describes the design, usage and some tests results obtained with this system. elec https://charleslabs.fr/en/project-Microfluidics+Electrowetting+platform https://charleslabs.fr/en/project-Microfluidics+Electrowetting+platform Wed, 20 Jan 2021 00:00:00 +0100 This 3D Lidar utilizes an innovative mechanical scanning system to achieve high-resolution scans at an exceptional scanning rate. The Lidar employs a mirror to scan the beam throughout the room, without the need for any moving electronic parts. What's more, it can be fully 3D-printed. This article offers detailed insights into the design, construction, and usage of this device. elec https://charleslabs.fr/en/project-3D+Lidar+Scanner+MK2 https://charleslabs.fr/en/project-3D+Lidar+Scanner+MK2 Wed, 14 Oct 2020 00:00:00 +0200 Radio astronomy is the study of celestial objects at radio frequencies. An amateur astronomer with a very simple and inexpensive setup can perform some interesting measurements. This article describes my Ku band setup and some experiments we can do with it. elec https://charleslabs.fr/en/project-Radio+Astronomy+Basics https://charleslabs.fr/en/project-Radio+Astronomy+Basics Mon, 07 Sep 2020 00:00:00 +0200 Irish Whistle Tabs is an open-source Android app to learn to play the tin whistle. It features hundreds of traditional Celtic tunes (jigs, reels, polkas, ballads, etc.). In this article, I showcase my app, and go into more technical details on the inner working. info https://charleslabs.fr/en/project-Irish+Whistle+Tab+-+Android+app https://charleslabs.fr/en/project-Irish+Whistle+Tab+-+Android+app Sun, 24 May 2020 00:00:00 +0200 Beamforming is a signal processing technique to get a directionnal signal transmission from an array of emitters. By controlling the relative phase and amplitude difference between the elements, we can shape the emission/reception pattern according to our needs. For this project, I designed, built and measured a phased linear array of speakers. elec https://charleslabs.fr/en/project-Acoustic+beamsteering+with+a+speaker+array https://charleslabs.fr/en/project-Acoustic+beamsteering+with+a+speaker+array Sat, 14 Mar 2020 00:00:00 +0100 Each key on a keyboard makes a slightly different, unique sound. In this article, I explore the possibility of extracting key-presses and passwords from audio recordings using digital signal processing and machine learning with a Python proof-of-concept script. info https://charleslabs.fr/en/project-Breaking+Passwords+with+a+Microphone https://charleslabs.fr/en/project-Breaking+Passwords+with+a+Microphone Fri, 27 Dec 2019 00:00:00 +0100 Reaction wheels are a way for spacecrafts such as the Hubble Space Telescope to achieve 3-axes attitude detumbling and control. It uses the conservation of angular momentum. For this project, I made a model of a satellite with a reaction wheel to demo the effect and play with the parameters/control algorithm. elec https://charleslabs.fr/en/project-Reaction+Wheel+Attitude+Control https://charleslabs.fr/en/project-Reaction+Wheel+Attitude+Control Thu, 28 Nov 2019 00:00:00 +0100 Shablocks is a modular and compact electronic lab system. It is made of open-hardware blocks: variable power supply, oscilloscope, component tester, etc. Everything can be assembled on the go to fit your needs. elec https://charleslabs.fr/en/project-Shablocks+-+Electronic+modular+lab https://charleslabs.fr/en/project-Shablocks+-+Electronic+modular+lab Sun, 22 Sep 2019 00:00:00 +0200 Electromyography (EMG) is a commonly used electrodiagnostic medicine technique for evaluating and recording the electrical activity produced by skeletal muscles. OpenEMG is a project that aims to create an open-source, easy-to-make EMG module that can capture muscle information from Arduino or any other micro-controller. With this module, users can measure muscle activity and use the data to explore various applications such as robotics and prosthetics. elec https://charleslabs.fr/en/project-OpenEMG+Arduino+Sensor https://charleslabs.fr/en/project-OpenEMG+Arduino+Sensor Tue, 18 Jun 2019 00:00:00 +0200 Accurate mapping of near-field electromagnetic parasitic emissions is crucial for designing, debugging, and pre-compliance testing of electronic devices. However, traditional EM scan methods are often expensive and lack the required level of detail and speed. This article describes two innovative methods for creating fast and affordable high-resolution 2D maps of RF EMI for printed circuit boards (PCBs) and other electronic devices. info https://charleslabs.fr/en/project-Electromagnetic+interference+mapping https://charleslabs.fr/en/project-Electromagnetic+interference+mapping Mon, 22 Apr 2019 00:00:00 +0200 The human hand is made up of a total of 27 individual bones connected by joints and ligaments, and operated by muscles situated in the hand and wrist. This project's objective is to mimic it and build an open-harware fully 3D-printed prosthetic hand. elec https://charleslabs.fr/en/project-3D-printed+prosthetic+hand https://charleslabs.fr/en/project-3D-printed+prosthetic+hand Sat, 06 Apr 2019 00:00:00 +0200 Digital image processing can be used to remove noise and signal distortion from pictures. It is particularly useful for astronomy, as the details are faint and often blurry. The objective of this project is to define an artificial neural network (ANN) and train it with machine learning to take several noisy, convoluted astronomy pictures and output a single processed photograph. info https://charleslabs.fr/en/project-AI+astronomy+pictures+processing https://charleslabs.fr/en/project-AI+astronomy+pictures+processing Fri, 08 Mar 2019 00:00:00 +0100 Electric ducted fans (EDF) are an efficient way of producing thrust for an aircraft. However, there are a lot of variables that can be fine tuned to optimize their performance: body curves, fan blade pitch, duct length, number of fan blades, etc. Using both simulation and experimental results, the objective of this small project is to enhance the thrust per input Watt of my design. elec https://charleslabs.fr/en/project-EDF+motor+design https://charleslabs.fr/en/project-EDF+motor+design Tue, 19 Feb 2019 00:00:00 +0100 Machine learning is fantastic to apply complex mathematical operations without being specifically programmed like in conventional algorithms. In this article, I share two artificial neural networks experiments related to digital signal processing (DSP): discrete Fourier transforms and signal corruption recovery. info https://charleslabs.fr/en/project-AI-powered+digital+signal+processing https://charleslabs.fr/en/project-AI-powered+digital+signal+processing Sun, 10 Feb 2019 00:00:00 +0100 Electronic filters are circuits which remove unwanted frequency components from the signal to enhance wanted ones. The hairpin topology is a microstrip band-pass filter for the gigahertz band (UHF). They can be very useful with SDR to improve the reception. This article features a Javascript generator for these. It also shows their design and my results. elec https://charleslabs.fr/en/project-Hairpin+filter+design https://charleslabs.fr/en/project-Hairpin+filter+design Sun, 05 Jul 2020 00:00:00 +0200 Homemade PCB manufacturing is a great way to get inexpensive board prototypes with no delay. In this article, I show the method I came up with to get reliable, fast and precise PCBs with no headaches using a 3D printer, a permanent marker and any etchant. elec https://charleslabs.fr/en/project-Homemade+PCB+manufacturing https://charleslabs.fr/en/project-Homemade+PCB+manufacturing Sun, 21 Oct 2018 00:00:00 +0200 Interact is a simple PHP open-source comment system that can be added to any website in minutes to improve interactivity and user's involvement. Client-side, it is very lightweight (<6 KB CSS and JS combined) and intuitive (no logins, no cookies, etc.). Server-side, it is very easy to setup, manage and even customize to fit your needs. info https://charleslabs.fr/en/project-Interact+PHP+-+comment+system https://charleslabs.fr/en/project-Interact+PHP+-+comment+system Fri, 17 Aug 2018 00:00:00 +0200 Software Defined Radio (SDR) is a radio communication system where components that have been traditionally implemented in hardware are instead implemented by means of software. RTL-SDR is an extremely inexpensive way to start exploring, demodulating, decoding... about anything you could thing of in the VHF and UFH radio range. This article is a quick start guide with RTL-SDR to begin capturing and decoding signal on GNU/Linux, and two simple example projects. info https://charleslabs.fr/en/project-Getting+started+with+RTL-SDR https://charleslabs.fr/en/project-Getting+started+with+RTL-SDR Tue, 24 Jul 2018 00:00:00 +0200 S3D Evolved is an open source 3D printer that is reliable, compact and inexpensive to build. Its 100x100x100 mm build volume and robust frame means that it can be transported easily, while being sufficient for most of your prints. elec https://charleslabs.fr/en/project-S3D+Evolved+-+compact+3D+printer https://charleslabs.fr/en/project-S3D+Evolved+-+compact+3D+printer Fri, 20 Jul 2018 00:00:00 +0200 Thrust vectoring is the ability of an aircraft, rocket, or other vehicle to manipulate the direction of the thrust from its motor in order to control the attitude of the vehicle. I started designing and building a model rocket with a gimbaled thrust system. Impulse is my open-source and cross-platform simulator for gimbaled thrust rockets that accurately simulates the rocket's physics. info https://charleslabs.fr/en/project-Gimbaled+Model+Rocket+Simulator https://charleslabs.fr/en/project-Gimbaled+Model+Rocket+Simulator Tue, 08 May 2018 00:00:00 +0200 Helmholtz coils are a pair of facing coils that generate an almost uniform magnetic field along one axis. In my end-of-study project at ECE Paris, we designed, built, and qualified a full 3D Helmoltz coil magnetic simulation environment for CubeSats. This environment enables the testing and verification of magnetometers and magnetorquers for the ADCS subsystem. elec https://charleslabs.fr/en/project-ECE3SAT+-+Helmholtz+Coils https://charleslabs.fr/en/project-ECE3SAT+-+Helmholtz+Coils Sun, 11 Feb 2018 00:00:00 +0100 This compact laser engraving CNC machine can burn on wood and most materials. It is upcycled with CD/DVD drives from old computers. It is a fairly easy machine to build and use, thanks to the open-source control software LaserGRBL. elec https://charleslabs.fr/en/project-Micro+Laser+Machine https://charleslabs.fr/en/project-Micro+Laser+Machine Sat, 10 Feb 2018 00:00:00 +0100 As a 3-day project, I created this 360° lidar scanner using a Garmin™ LIDAR-Lite v3. With its data acquisition and visualisation code, this turret can generate a fairly accurate 3D point cloud that we can import in CAD software. The source-code and some design details are available in the article. elec https://charleslabs.fr/en/project-3D+Lidar+Scanner https://charleslabs.fr/en/project-3D+Lidar+Scanner Sat, 28 Oct 2017 00:00:00 +0200 ElectroDB is a powerful, offline Android app I created for electronics enthusiasts like me. With its 12000+ (and growing) components database, you will find all the information you need to complete your electronic projects in less time. In this article, I showcase my app, and go into more technical details on the inner working. info https://charleslabs.fr/en/project-ElectroDB+-+Android+app https://charleslabs.fr/en/project-ElectroDB+-+Android+app Sat, 14 Oct 2017 00:00:00 +0200 This project is a custom processor architecture, written in VHDL and synthesized on a FPGA. The article covers the design, architecture, instruction set, testing, and some VHDL implementation details. elec https://charleslabs.fr/en/project-A+basic+VHDL+processor https://charleslabs.fr/en/project-A+basic+VHDL+processor Tue, 18 Apr 2017 00:00:00 +0200 In this article, I describe the requirements and the technical choices I have made for the development of my personal website (the website you are currently browsing). It includes information about the frameworks, content management system, hosting, etc. info https://charleslabs.fr/en/project-My+personal+Website https://charleslabs.fr/en/project-My+personal+Website Sun, 08 Jan 2017 00:00:00 +0100 Simply Appear is an extremely lightweight native Javascript and CSS framework to handle apparition animations. It is easy to implement and include basic animations. As it does not use jQuery, it is lightning fast and weights less than 2KB! info https://charleslabs.fr/en/project-Simply+Appear https://charleslabs.fr/en/project-Simply+Appear Sat, 07 Jan 2017 00:00:00 +0100 This project describes the technologies, framework and processes to design the new website of a French law practice situated in Orléans. It is a responsive, accessible, static, showcase website that I fully created from scratch. info https://charleslabs.fr/en/project-Website+for+ALC https://charleslabs.fr/en/project-Website+for+ALC Thu, 05 Jan 2017 00:00:00 +0100