Posts

Project Summary This post goes through the process of building a freezer temperature monitoring device. Here are the main features: It triggers an alarm signal whenever the freezer temperature goes above a predefined threshold for a certain period of time. Real time temperature readings are sent to Adafruit.IO private IoT portal. Device is fully compatible with Apple’s HomeKit. Therefore, Home automations can be setup to be executed upon high temperature alarm (i.e. lamp in bedroom turns on bright red). The diagram below shows all the hardware components and how they communicate with the Homebridge server, router and mobile devices. ...

A quick glance at the projects I’ve posted on this website makes it evident that I prefer to use CircuitPython when programming microcontrollers. Adafruit and the community have done an exceptional job maintaining the language and releasing libraries for a wide variety of sensors and peripherals. You can iterate, troubleshoot and finalize a project considerably faster than when using something like Arduino, for example. The Version Control Problem Just like coding on a computer, CircuitPython would benefit from some form of version control, like git. However, since the code resides in the microncontroller’s internal memory, which is usually very limited, it doesn’t make much sense to keep a version control system on device. This leaves us with only one option: working off of a local folder in the computer and setup git there. Then, when ready to test, drag the appropriate files to the microcontroller. This, however, is a tedious process and doesn’t facilitate rapid prototyping. ...

This post describes how I put together a bluetooth connected ambient conditions sensor using a microcontroller and CircuitPython. Although this device can be used to monitor ambient conditions anywhere, I built it with a specific purpose in mind: monitoring temperature and humidity inside plastic containers storing 3D printer filament spools. Some 3D printer filaments are very susceptible to high humidity conditions (e.g. ABS) and can quickly degrade. Manufacturers recommend to keep them in areas with humidity conditions below 50% and ambient temperature not exceeding 30 Celsius. I have several of these spools stored in a couple of (supposedly) air-tight big plastic containers. Therefore, I wanted a device with the following features: ...

Background A few months ago I started looking for ways to alleviate the wrist and shoulder pain I’ve been dealing with for a long time. I adjusted my home office desk, chair and computer monitor to be as ergonomic as possible. I did some research on ergonomic computer peripherals and tried out several of them. It didn’t take me long to land in the fascinating and addictive world of mechanical keyboards. ...

Summary The objective of this project is to create a solar powered, HomeKit connected outdoor fence door monitoring device. Once setup, the door’s state (i.e. open/close) can be monitored and used in automations within the HomeKit ecosystem. I’ve been using it for months now, and it has been working really well. See below a video of the system in action. This is not a difficult project, but there are several moving parts associated to it, so I’ll try to be thorough in the following sections. ...