https://rogmendoza.com/blog/ Embedded systems, PCB design and automation. Projects, career highlights and notes from the bench — ESP32, KiCad, OpenSCAD, FastAPI and AI-assisted engineering. en-us https://rogmendoza.com/blog/solveblock-core-rev-c/ https://rogmendoza.com/blog/solveblock-core-rev-c/ Tue, 06 Oct 2026 12:00:00 +0000 From a dev board on a breadboard to a custom ESP32-S3 PCB — the layout, the manufacturer checks, the firmware architecture that runs on more than one board, and an honest milestone list. https://rogmendoza.com/blog/the-bug-that-would-have-dialled/ https://rogmendoza.com/blog/the-bug-that-would-have-dialled/ Sat, 03 Oct 2026 12:00:00 +0000 Adding a dial-up telephone carrier to a LoRa mesh exposed a routing bug that no test caught — it would have been discovered as a phone bill. https://rogmendoza.com/blog/first-packet-across-real-air/ https://rogmendoza.com/blog/first-packet-across-real-air/ Tue, 29 Sep 2026 12:00:00 +0000 Two Heltec V3 radios, one evening, and a round-trip time predicted before it was measured. What the first real-RF runs of Dictyon-net taught me about honest arithmetic. https://rogmendoza.com/blog/take-the-theorem-test-the-claim/ https://rogmendoza.com/blog/take-the-theorem-test-the-claim/ Thu, 24 Sep 2026 12:00:00 +0000 I gave 3-6-9 numerology, vortex mathematics and the Rodin coil one honest test each. Most claims didn't survive — but the mathematics hiding inside them produced the biggest engineering gain in the project. https://rogmendoza.com/blog/the-maker-loop/ https://rogmendoza.com/blog/the-maker-loop/ Tue, 22 Sep 2026 12:00:00 +0000 Hardware, firmware, software and customers all respond to the same loop. A look at how I take an idea from first sketch to working prototype — and why the loop matters more than any tool. https://rogmendoza.com/blog/null-is-a-deliverable/ https://rogmendoza.com/blog/null-is-a-deliverable/ Fri, 18 Sep 2026 12:00:00 +0000 A burst of AI-assisted research produced 88 findings in two days. Auditing them against their own rules found that the filter never ran — and that the audit was the most useful finding of all. https://rogmendoza.com/blog/four-enclosures-one-script/ https://rogmendoza.com/blog/four-enclosures-one-script/ Wed, 09 Sep 2026 12:00:00 +0000 Block, flat, wedge or stand? Generating every candidate enclosure from one parametric source turned an argument about taste into a quick, fair comparison. https://rogmendoza.com/blog/every-screen-from-the-firmware/ https://rogmendoza.com/blog/every-screen-from-the-firmware/ Wed, 26 Aug 2026 12:00:00 +0000 A normal solve costs zero input, the coach stays quiet most of the time, and there's no scramble generator on purpose. The interface decisions behind SolveBlock, shown in the device's own screens. https://rogmendoza.com/blog/the-starter-stack/ https://rogmendoza.com/blog/the-starter-stack/ Tue, 18 Aug 2026 12:00:00 +0000 The tools and sequence I use to take an idea from zero to something real customers can touch — and the things I deliberately postpone. https://rogmendoza.com/blog/from-scanner-to-gammajuice/ https://rogmendoza.com/blog/from-scanner-to-gammajuice/ Tue, 04 Aug 2026 12:00:00 +0000 Turning a Python squeeze scanner into a signals product — a dashboard, a content site on a headless CMS, automated social posts and the engagement data that changed what we publish. https://rogmendoza.com/blog/affiliate-links-rot/ https://rogmendoza.com/blog/affiliate-links-rot/ Tue, 28 Jul 2026 12:00:00 +0000 Programs change, products disappear and redirects break quietly. A practical system for keeping hundreds of affiliate links healthy without checking them by hand. https://rogmendoza.com/blog/the-80-percent-win-rate-that-wasnt/ https://rogmendoza.com/blog/the-80-percent-win-rate-that-wasnt/ Tue, 21 Jul 2026 12:00:00 +0000 A backtest dashboard showed squeeze signals winning 80% of the time. Two lines of code explained why — an outcome-defined label and exits at the peak price. https://rogmendoza.com/blog/backtesting-a-squeeze-scanner/ https://rogmendoza.com/blog/backtesting-a-squeeze-scanner/ Tue, 14 Jul 2026 12:00:00 +0000 A thin edge, two filters that sounded smart and didn't help, and a liquidity effect hiding in plain sight. What 2,633 historical signals from the 3WT scanner actually said. https://rogmendoza.com/blog/power-budgets-battery-esp32/ https://rogmendoza.com/blog/power-budgets-battery-esp32/ Tue, 07 Jul 2026 12:00:00 +0000 Duty cycles, deep sleep, regulators that leak and the multimeter habit that saves you from surprises. A practical guide to battery life on ESP32 boards. https://rogmendoza.com/blog/wild-ideas-as-testable-hypotheses/ https://rogmendoza.com/blog/wild-ideas-as-testable-hypotheses/ Tue, 16 Jun 2026 12:00:00 +0000 Ternary-Six9 is an experimental communications concept. Here's how I keep unusual ideas honest — models, fixtures, baselines and logged measurements before any conclusions. https://rogmendoza.com/blog/seo-is-a-data-problem-affrank/ https://rogmendoza.com/blog/seo-is-a-data-problem-affrank/ Tue, 02 Jun 2026 12:00:00 +0000 Rankings, keywords, metadata, structured FAQs and affiliate links all change constantly. AffRank.ai treats site management like data engineering — with reviewable changes. https://rogmendoza.com/blog/esp32-vs-rp2350/ https://rogmendoza.com/blog/esp32-vs-rp2350/ Tue, 26 May 2026 12:00:00 +0000 A practical comparison of two microcontrollers I use constantly — radios, real-time I/O, power, tooling and the questions that settle the choice in five minutes. https://rogmendoza.com/blog/mesh-networking-lessons-dictyon-net/ https://rogmendoza.com/blog/mesh-networking-lessons-dictyon-net/ Tue, 05 May 2026 12:00:00 +0000 What I'm learning while building a decentralized, low-power communications mesh on ESP32 and RP2350-class hardware — identity, addressing, multipath and measuring everything. https://rogmendoza.com/blog/fastapi-postgres-default-stack/ https://rogmendoza.com/blog/fastapi-postgres-default-stack/ Tue, 28 Apr 2026 12:00:00 +0000 For small products, dashboards and device back-ends, I keep reaching for the same boring, reliable stack. Here's the setup and why it holds up. https://rogmendoza.com/blog/ai-reviews-the-board-the-datasheet-decides/ https://rogmendoza.com/blog/ai-reviews-the-board-the-datasheet-decides/ Tue, 14 Apr 2026 12:00:00 +0000 How I use Python, MCP-connected tools and AI assistants to speed up schematic reviews, routing checks and firmware tests — and the verification rules I never skip. https://rogmendoza.com/blog/openscad-enclosures-as-code/ https://rogmendoza.com/blog/openscad-enclosures-as-code/ Fri, 27 Mar 2026 12:00:00 +0000 Parametric enclosures, tolerance variables and fit-check prints — how treating plastic like source code made my hardware iterations faster. https://rogmendoza.com/blog/board-bring-up-checklist/ https://rogmendoza.com/blog/board-bring-up-checklist/ Tue, 10 Mar 2026 12:00:00 +0000 The step-by-step routine I follow when a fresh PCB arrives — from a current-limited first power-up to a known-good firmware baseline. https://rogmendoza.com/blog/the-timer-is-the-source-of-truth/ https://rogmendoza.com/blog/the-timer-is-the-source-of-truth/ Tue, 24 Feb 2026 12:00:00 +0000 Why SolveBlock never re-times a solve, how we compute averages with integer math, and what "deterministic" really means for a tiny embedded device. https://rogmendoza.com/blog/from-napkin-to-pcb-solveblock/ https://rogmendoza.com/blog/from-napkin-to-pcb-solveblock/ Tue, 03 Feb 2026 12:00:00 +0000 How a speedcubing idea became a custom ESP32 board — the requirements, the schematic decisions, the layout tradeoffs and the mistakes I'd happily make again. https://rogmendoza.com/blog/structured-outputs-prompt-engineering/ https://rogmendoza.com/blog/structured-outputs-prompt-engineering/ Tue, 27 Jan 2026 12:00:00 +0000 How I design LLM prompts and schemas that return reliable JSON for analytics, reporting and automation — plus the validation layer that catches everything else. https://rogmendoza.com/blog/why-the-esp32-is-my-blank-page/ https://rogmendoza.com/blog/why-the-esp32-is-my-blank-page/ Mon, 12 Jan 2026 12:00:00 +0000 Wi-Fi, Bluetooth, two cores and a pile of peripherals for the price of lunch. Here's why nearly every idea I have starts on an ESP32 — and when it shouldn't. https://rogmendoza.com/blog/automation-people-actually-adopt/ https://rogmendoza.com/blog/automation-people-actually-adopt/ Tue, 09 Dec 2025 12:00:00 +0000 Lessons from building onboarding, CRM and AI workflows — including an LLM-assisted onboarding flow that cut onboarding time by 35%. Adoption is the real metric. https://rogmendoza.com/blog/what-hospital-networks-taught-me-about-hardware/ https://rogmendoza.com/blog/what-hospital-networks-taught-me-about-hardware/ Tue, 18 Nov 2025 12:00:00 +0000 Citrix farms, hospital uptime and change control don't sound like PCB design. They turned out to be the best training I could have had. https://rogmendoza.com/blog/n8n-or-code/ https://rogmendoza.com/blog/n8n-or-code/ Tue, 14 Oct 2025 12:00:00 +0000 Visual workflow tools and plain Python both have a place. A practical guide to choosing between them — and to the hybrid approach most of my automation uses. https://rogmendoza.com/blog/lessons-from-17000-customers/ https://rogmendoza.com/blog/lessons-from-17000-customers/ Tue, 16 Sep 2025 12:00:00 +0000 Twelve years of building the systems behind a direct-sales business — e-commerce, CRM, email/SMS and training — and the product lessons that carried over into engineering.