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Welcome to the Internet Home of John M. Wargo; I created this site back in 2009 so I could post articles about things that interested me. Herein you’ll find articles on a lot of different topic areas: Mobile development, Web development, Internet of Things (IoT), and a lot more. Every time I learn some new technology or complete some cool or interesting development or IoT project I publish an article here.
You’ll also find information about my books, source code projects on GitHub, and articles published in or on other sites or magazines, even videos of my many conference presentations or project demonstrations. I’m also especially fond of the series of Stupid Developer Tricks posts.
You can view all articles in reverse chronological order, or you can find articles by category. Of course, if you can’t find what you need in those views, use Search to find anything anywhere on the site.
Note: An AI Generated pill displayed in the list below indicates that the post description displayed on the page was generated from the post content using Generative AI (GenAI). The post content itself was written by a human (me).
A while back, I learned about this ESP32 project called Info Orbs; it's a simple project that pairs 5 1.8 inch circular displays with a simple stand and some pretty cool software. The kit seems to be designed as a first project for people interested in getting into Arduino; it requires a little bit of soldering and the entire software configuration and deployment process runs in Visual Studio Code. The assembly instructions are simple and easy to follow.
A few weeks ago I published an article called ESP32 Connect Using HTTPS that demonstrated how to build an Arduino sketch for the ESP32 platform that connected to a remote server using TLS (HTTPS). I wrote that article because I wanted to learn how to connect to a REST API running on a server online and I knew that most (all) modern API servers required TLS.
Received a scam/phishing email the other day that really surprised me. The message is so clearly a scam that I wonder why they even bothered to send it. Here's the email message:
An interesting email showed up in my inbox this morning. Interesting because it appears to be from Oracle (and I work for Oracle) but there's a whole bunch of weirdness about the message. Take a look, here's the message:
AI Generated I'm excited to find out that my Certificate to Arduino announcement post made it into Google Gemini.
Before I created the web application described in Automated Public Cert to Arduino Header Conversion, I started with a simple node.js command-line utility. I like command-line tools and starting with the Node version made sense to me. I switched to the web app version once I realized that most people who needed to do the certificate conversion to Arduino wouldn't have node installed on their development systems.
As I described in my previous post, I'm working on a project where I'm using an M5Stack device to interact with a Google Firebase Function I have running in the cloud. As I started planning my project's code, I realized that the SSL (HTTPS) requirement Firebase Functions forces on applications would be a problem for me.
AI Generated I was working on a project using an M5Stack device to interact with a Google Firebase Function, but I ran into an issue with the SSL requirement. After exploring different options, I found that ESP32 devices could send HTTPS requests, but required the server's public cert embedded in the code. To simplify this process, I created a web app called Cert2Arduino that automates the conversion of public certificates into Arduino-compatible code.
I received an interesting text message the other day purporting to be a message from Amazon letting me know about a "refundable order that needs to be processed." I could tell immediately that it was a scam or phishing attempt, so I thought I'd share what I saw.
AI Generated I recently revamped my web app that helps accurately calculate reading progress in Goodreads. The app now looks much better thanks to MVP.css, and I upgraded it to React 19 while removing Bootstrap. The new design is cleaner and more visually appealing, making it easier to use.
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View details regarding the books I authored.
View a list of all of the articles I published in other publications (besides here).
View some of my projects that span multiple posts on this site or multiple GitHub repositories.
You can find me on more places than this site; the Sightings page lists the other places where you can find stuff I created.
View the source code projects in my public GitHub account.
Public packages I published on npm.
View a list of all of my upcoming events (conference presentations, product demos, etc.).
View a list of the Internet sites I maintain.