Direct control of the XL 320 servo with a Raspberry

This post introduces a custom C++ library to control the popular Dynamixel XL 320 servo directly with a Raspberry Pi 4, without the need for an additional controller/shield like the OpenCM board. You'll just need a level shifter to drive the motor and LED and an additional logic gates IC in case you want to read the servo's output, but these are cheap and popular electronic components. The Rasberry configuration and wiring are included, with everything you need to have a working setup rapidly.


A foldable shield for face protection

In the context of the pandemic of SARS-CoV-2 I've been actively working on a design of foldable head shield that could be produced in large quantities. In this post I provide all the details about this project, including the blueprints and production instructions for makers.


Extended safety eyewear lenses

The current pandemic of COVID-19 compels medical staff to rapidly adapt the equipment at their disposal to manage this threat. In this post I show how to extend the protection offered by disposable safety eyeware lenses. I also share the blueprint and cut files so that anyone can easily reproduce it.


Mask holders to relieve ear pain

In the emergency of the COVID-19 pandemic, a large numbers of caregivers are at the frontline to perform tests an assist patients. Among other protection equipments, the disposable masks with elastic straps may be worn all day long and cause pain at the back of the ears. I designed a small plastic ribbon to prevent this, and I share the blueprint and cut files so that anyone can easily reproduce it.


Mechanical cheatsheet for CAD and 3D printing

Here is a one-page cheatsheet with selected info for standard metric screws, threaded inserts, hexagonal nuts and square nuts. In addition you also have the dimensions of the holes to insert in a design for 3D printing. To print and pin on your wall if you design awesome parts on a regular basis!


A complete 8-bit cheatsheet

Here is a one-page cheatsheet with all decimal, hexadecimal and binary codes for all digits from 0 to 255. In addition you also have the corresponding characters (i.e. the standard ASCII characters for the first 128 digits) which is often useful to have on hand. To print and pin on your wall if you are often programming devices at a low-level!


A stackable manifold for micro-valves

There can be numerous good reasons to use a computer-controlled microvalve: with low dead volumes and fast switching times they can be used for millifluidics, microfluidics or automation. Two common pitfalls are the driving electronics and the mechanical connection of the valve with the circuit. In this post I detail how to build a stackable manifold with Luer connectors for microvalves driven by a digital signal. Download all conception files for easy replication!