Meshtastic Build-Off 2026: Designing the RetroMeshDevice PCB

As I announced to my newsletter subscribers, I knew I was going to be busier than usual participating in the Meshtastic Build-Off 2026 competition. Rather than leaving the blog without new posts in the meantime, and because I think this can be a genuinely interesting series, I decided to write about parts of this process so you can follow along with the development of a device from PCB to firmware integration. Though in this case, the firmware side will be a bit different from the usual, since the goal is to get my new hardware running with Meshtastic's existing firmware.The device I'm building is called the RetroMeshDevice. The idea was to build a companion node that is as minimal as possible and doesn't…

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How to evaluate antennas for Meshtastic / MeshCore using a NanoVNA

Not all antennas that come with Meshtastic and MeshCore kits are equal, even if they look the same. While testing these networks, I've come across a wide variety of antennas — many of them bundled with different kits I've picked up along the way. It's true that in field tests, some of them allow you to reach further and get better performance with the same hardware, but you never really know exactly why.That got me wondering whether I could characterize them using some kind of equipment, rather than relying on field tests and trial and error. After some research, I came across a tool born from the maker world that lets us measure LoRa antennas at 868 MHz easily and without the need…

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Deploying a Meshcore repeater. How to perform OTA updates on NRF devices.

Introduction Deploying a reliable repeater node in a Meshcore network involves many aspects that need to be considered. What chip are we going to use and what consumption does it have, what type of batteries will power the equipment, how much will we size the solar panels that will charge the equipment, what will be the lifetime of the equipment. All these aspects are basic and very important, since a repeater should be located in the highest possible area to maximize its connectivity with other nodes and very likely it will have somewhat limited access. For example, if we deploy it on a roof, we won't be climbing up every other day to fix problems. Apart from these problems I mentioned, there is…

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How to Flash Zephyr RTOS on Windows: XIAO Boards Guide

There is a growing interest in Zephyr RTOS within the embedded community. Unlike Arduino or ESP-IDF, Zephyr gives you a real hardware abstraction layer that lets you write firmware once and compile it for completely different microcontrollers without changing a single line of application code. Think of it as bringing Linux-style portability to the embedded world. That's exactly what I wanted to put to the test. I have four Seeed Studio XIAO modules on my bench: the nRF52840, nRF54L15, ESP32-S3, and ESP32-C6 and while they all share the same tiny 21×17.8 mm footprint and pinout, their cores are completely different. My goal is to benchmark their real-world power consumption and execution times using a single Zephyr firmware that compiles for all of them,…

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How to flash Meshcore firmware

In this guide, I will explain how to flash Meshcore firmware onto any device. One thing that people might not know is that most of the devices that are sold with Meshthastic firmware, can be flashed with Meshcore firmware by following these steps.For this guide, I will be using the Seeed Wio Tracker L1 Pro module from SeeedStudio with the preloaded Meshtastic firmware, which is the model I have on hand. This is one of the devices that I was talking about in the previous paragraph. I bought it with Meshtastic firmware, but It supports firmware for both Meshcore and Meshtastic networks.Link to buy: Wio Tracker L1 Pro - Meshtastic [Aliexpress]Link to buy: Wio Tracker L1 Pro - Meshcore [Aliexpress]Link to buy: Wio…

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MeshCore vs Meshtastic: Getting started with Seeed Studio LoRa hardware

Over the last few weeks, I’ve been analyzing LoRa networks (MeshCore and Meshtastic), trying to understand how they work and seeing how they perform in my local environment. I started with zero prior knowledge of the network, so in this post, I will try to explain the basic things for people who want to get started, providing a clear vision of how it works. I’ll answer several questions: the choice of protocol, the hardware I ended up using, and my first real impressions after setting it up. 1. Understanding the network There is a very common misunderstanding when someone first discovers LoRa mesh networks like Meshtastic or MeshCore. People assume they are a solution for setting up their own sensor network, independent of…

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Best Logic Analyzers in 2026: A complete selection guide

In this post, I’ve put together a selection guide to help you choose the right logic analyzer based on your protocol requirements and budget. From my perspective, if you are working with electronic systems, across all levels of hardware, including entry-level microcontrollers (STM32, ESP32, Arduino) to SBCs (Raspberry Pi, BeagleBoard, etc.), a logic analyzer is a must tool in your lab.When you start looking for one, you'll notice a massive price gap depending on performance. While there is plenty of information online, most sources lack a deep technical comparison between the current models on the market.In this guide, I will break down the essential technical specs you must evaluate before purchasing. Following that, I’ll analyze several logic analyzers and their core features, concluding…

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Serverless e-Ink Photo Frame: Using Google Drive for unlimited storage

If you want to build your own e-Ink Photo Frame but want to forget about setting up local servers (Raspberry Pi, NAS, or Home Assistant) and don't want to rely on SD cards, this project is for you.The biggest hurdle when using e-Ink displays for photos is the infrastructure. Normally, you need a 24/7 dedicated server to process the images or pay for third-party services. Additionally, microcontrollers like the ESP32 face two critical constraints: Processing: Running a dithering algorithm (to adapt a real photo to the screen's limited color palette) is too heavy for an ESP32. Memory: High-quality images consume too much RAM during HTTP requests, often leading to crashes or overflow errors. To solve this, I decided to use Google Drive as…

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Cheapest DIY E-Paper picture frame. Ikea Hack

Digital e-paper frames have become very popular lately. They are the perfect addition to any desk or living room, but when I looked into buying one, the prices seemed completely out of orbit. We’re talking about extremely high prices for what they actually offer. I preferred to find a way to build my own: customizable and, above all, much more affordable and, why not, based on an IKEA frame that costs just a few euros.I found the 13.3-inch Spectra displays with support for up to 6 colors. While researching suppliers, I came across the XIAO ePaper DIY (EE02) kit from Seeed Studio. What’s interesting about this kit is that, besides the panel, it includes a controller board with everything you need to get…

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How to Create a Custom RP2350 Magic Ball (Elon Musk Edition)

Over the last few weeks, I’ve been experimenting with round LCD displays to see what they can really do. The moment I held one in my hand, I had a total Toy Story flashback: Woody asking the Magic 8-Ball for advice.I never actually owned one as a kid, so I thought... why not build my own? But let's take it a step further. Instead of the classic cryptic answers, why not get advice from Elon Musk, Clint Eastwood, or your favorite celebrity? That’s how the RP2350 Magic Ball project was bornFor those who don't know, the Magic Ball was invented in 1946. It is a ball with the appearance of a billiard ball containing an icosahedron floating in liquid. This icosahedron has answers…

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