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104 Articles

Advanced PCB Graphics With KiCAD 6 And Inkscape

January 8, 2022 by 16 Comments

There are many, many video tutorials about designing the functional side of PCBs, giving you tips on schematic construction, and layout tips. What is a little harder to find are tutorials on the graphical aspects, covering the process from creating artworks and how you can drive the tools to get them looking good on a PCB, leveraging the silkscreen, solder and copper layers to maximum effect. [Stuart Patterson] presents his guide for Advanced PCB Graphics in KiCAD 6.0 and Inkscape, (Video, embedded below) to help you on your way to that cool looking PCB build.

Silkscreen layers in yellow, solder mask opening in red

The first step is to get your bitmap, whether you create it yourself, or download it, and trace it into a set of vectors using the Inkscape ‘trace bitmap’ tool. If you started with an SVG or similar vector shape, then you can skip that stage.

Next simply create a PCB outline shape by deleting all the details that aren’t part of the outline. A little scaling here and there to get the dimensions correct and you’re done with the first part. [Stuart] has an earlier video showing that process.

The usability improvements in KiCAD 6.0 are many, but one greatly demanded feature is the ability to group objects, just like you do in Inkscape and any other vector graphics tool for that matter. That means you can simply import that SVG outline into the Edge.Cuts PCB layer and all the curves will be nicely tied together. Next you select the details you want for the silkscreen layer, solder mask removal layers and any non-circuit copper. In Inkscape it would be wise to use the layers feature to assign the different material types to a uniquely named layer, so they can be hidden for exporting. This allows you to handle silk, mask and copper PNG exports from a single master file, in addition to any vector details for outline, slots and holes.

Once you have PNG bitmap exports for the silk, mask etc. you need to create a footprint inside a board-specific library, using the KiCAD image converter tool. It was interesting to note that you can export a new image footprint from the tool and paste it straight into the footprint editor, and tweak all the visibility details at the same time. That will save some time and effort for sure. Anyway, we hope this little tutorial from [Stuart] helps, and we will be sure to bring you plenty more in the coming months.

Need some more help with KiCAD? Checkout this tutorial, and if you want a bit more power from the tool, you need some action plugins!

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Learn Bil Herd’s DIY Surface Mount Assembly Process

February 2, 2021 by 40 Comments

You can do your own Surface Mount Technology based PCB assembly with just a handful of tools and some patience. At the heart of my SMT process is stopping to inspect the various steps all while trying to maintain a bit of cleanliness in the process.

Surface mount or Surface Mount Technology (SMT) is the modern way to assemble Printed Circuit Boards (PCB) and is what is commonly seen when opening a modern piece of tech. It’s much smaller than the older Through-Hole (TH) technology where the component leads were inserted into holes in PCB, and act we called “stuffing” since we had to stuff the components into the holes.

A few specialized tools make this a lot easier, but resourceful hackers will be able to pull together a solder paste stencil jig, vacuum tweezers, and a modified toaster oven with a controller that can follow the reflow profile of the solder paste. Where you shouldn’t skimp is on the quality, age, and storage of the solder paste itself.

Join me after the break for my video overview of the process I use in my workshop, along with details of every step of my SMT assembly process.

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3D Printed Gesture-Controlled Robot Arm Is A Ton Of Tutorials

January 20, 2021 by 2 Comments

Ever wanted your own gesture-controlled robot arm? [EbenKouao]’s DIY Arduino Robot Arm project covers all the bases involved, but even if a robot arm isn’t your jam, his project has plenty to learn from. Every part is carefully explained, complete with source code and a list of required hardware. This approach to documenting a project is great because it not only makes it easy to replicate the results, but it makes it simple to remix, modify, and reuse separate pieces as a reference for other work.

[EbenKouao] uses a 3D-printable robotic gripper, base, and arm design as the foundation of his build. Hobby servos and a single NEMA 17 stepper take care of the moving, and the wiring and motor driving is all carefully explained. Gesture control is done by wearing an articulated glove upon which is mounted flex sensors and MPU6050 accelerometers. These sensors detect the wearer’s movements and turn them into motion commands, which in turn get sent wirelessly from the glove to the robotic arm with HC-05 Bluetooth modules. We really dig [EbenKouao]’s idea of mounting the glove sensors to this slick 3D-printed articulated gauntlet frame, but using a regular glove would work, too. The latest version of the Arduino code can be found on the project’s GitHub repository.

Most of the parts can be 3D printed, how every part works together is carefully explained, and all of the hardware is easily sourced online, making this a very accessible project. Check out the full tutorial video and demonstration, embedded below.

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Grasp Kotlin’s Coroutines With This Short Tutorial

August 31, 2020 by 1 Comment

Kotlin is a relatively new programming language; a derivative of Java with lots of little handy functional bits such as coroutines. [Foalyy] is porting an app to Android and learning Kotlin at the same time, and after wrapping their mind around coroutines, has written up a concise five-part tutorial on them.

Coroutines in Kotlin are a way to simplify writing asynchronous code, which is code that doesn’t necessarily execute in the order it is written. Coroutines are like light-weight threads that can be launched and managed easily, making it simpler to bridge together blocking and non-blocking code. (However, coroutines are not threads. They are more akin to suspending functions that play very well together.)

[Foalyy] found that the official Kotlin documentation on coroutines went into great detail on how coroutines function, but wanted a more bottom-up approach to understanding how they work and can be used. Luckily for anyone who thinks the same way, [Foalyy] wrote it all up and begins with a great recap of important elements, but if you prefer you can jump straight to the examples.

Kotlin has been around for a while, and readers with sharp memories may recall it was featured in this excellent introduction to what neural networks are and how they work.

Two-Part, Four-Wire Air Quality Meter Shows How It’s Done

August 25, 2020 by 34 Comments

The Bosch BME680 is a super-capable environmental sensor, and [Random Nerd Tutorials] has married it to the ESP32 to create an air quality meter that serves as a great tutorial on not just getting the sensor up and running, but also in setting up a simple (and optional) web server to deliver the readings. It’s a great project that steps through everything from beginning to end, including how to install the necessary libraries and how to program the ESP32, so it’s the perfect weekend project for anyone who wants to learn.

The BME680 is a small part that communicates over SPI or I2C and combines gas, pressure, temperature, and humidity sensors. The gas sensor part detects a wide range of volatile organic compounds (VOCs) and contaminants, including carbon monoxide, which makes it a useful indoor air quality sensor. It provides only a relative measurement (lower resistance corresponds to lower air quality) so for best results it should be calibrated against a known source.

The tutorial uses the Arduino IDE with an add-on to support the ESP32, and libraries from Adafruit. Unfamiliar with such things? The tutorial walks through the installation of both. There’s a good explanation of the source code, and guidance on entering setup values (such as local air pressure, a function of sea level) for best results.

Once the software is on the ESP32, the results can be read from the serial port monitor. By going one step further, the ESP32 can run a small web server (using ESPAsyncWebServer) to serve the data to any device wirelessly. It’s a well-written tutorial that covers every element well, and complements this other BME680-based air quality meter that uses MQTT and Raspberry Pi.

Learn Quantum Computing With Spaced Repetition

June 19, 2020 by 2 Comments

Everyone learns differently, but cognitive research shows that you tend to remember things better if you use spaced repetition. That is, you learn something, then after a period, you are tested. If you still remember, you get tested again later with a longer interval between tests. If you get it wrong, you get tested earlier. That’s the idea behind [Andy Matuschak ‘s]and [Michael Nielsen’s] quantum computing tutorial. You answer questions embedded in the text. You answer to yourself, so there’s no scoring. However, once you click to reveal the answer, you report if you got the answer correct or not, and the system schedules you for retest based on your report.

Does it work? We don’t know, but we have heard that spaced repetition is good for learning languages, among other things. We suspect that like most learning methods, it works better for some people than others.

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Car Alternators Make Great Electric Motors; Here’s How

January 16, 2020 by 195 Comments

The humble automotive alternator hides an interesting secret. Known as the part that converts power from internal combustion into the electricity needed to run everything else, they can also themselves be used as an electric motor.

The schematic of a simple automotive alternator, from US patent 3329841A filed in 1963 for Robert Bosch GmbH .
The schematic of a simple automotive alternator, from US patent 3329841A filed in 1963 for Robert Bosch GmbH.

These devices almost always take the form of a 3-phase alternator with the magnetic component supplied by an electromagnet on the rotor, and come with a rectifier and regulator pack to convert the higher AC voltage to 12V for the car electrical systems. Internally they have three connections to the stator coils which appear to be universally wired in a delta configuration, and a pair of connections to a set of brushes supplying the rotor coils through a set of slip rings. They have a surprisingly high capacity, and estimates put their capabilities as motors in the several horsepower. Best of all they are readily available second-hand and also surprisingly cheap, the Ford Focus unit shown here came from an eBay car breaker and cost only £15 (about $20).

We already hear you shouting “Why?!” at your magical internet device as you read this. Let’s jump into that.

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