Engineering Notebook
Experiments, projects and experiences in software, energy and technology.
Project notebooks
Modbus Anywhere
An embedded bridge built on an ESP32 that exposes data from industrial devices using Modbus over RS-485 as a clean HTTP API and MQTT messages, making legacy energy equipment easy to integrate with modern software systems.
Ampernomics
Ampernomics analyses a household’s real half-hourly electricity use to compare tariffs and model the financial impact of solar and battery storage, turning complex energy data into practical recommendations.
Latest posts
Modbus Anywhere Test Firmware
Notes from bringing up deliberately simple ESP-IDF test firmware for Modbus Anywhere: console commands, Wi-Fi, MQTT, mDNS, and an SDM120 read.
Modbus Anywhere PCB design
Design notes from turning a Modbus prototype into a DIN-rail PCB that can live in the cabinet instead of dangling from a USB dongle.
Using the Seeed Studio XIAO RS485 breakout for a Modbus prototype
Notes from prototyping Modbus RTU with a Seeed XIAO RS485 breakout and an Eastron SDM120, including a working Arduino sketch.
Web-based Microcontroller Setup - Part 3
My first attempt at Web Blueooth communicating with an Arduino sketch running on an ESP32 microcontroller from a web page to configure WiFi and then call an API on the uC.
Web-based Microcontroller Setup - Part 2
Part 2 of explorations into using Web Blueooth to communicate with a microcontroller from a web page. This experiment builds a Shelly client using just JavaScript and the Web Bluetooth API to make RPC calls to a Shelly relay.
Web-based Microcontroller Setup - Part 1
An initial exploration into using Web Blueooth to communicate with a microcontroller from a web page with a view to using this as a simple way of setting up a new device without using the Wireless Access Point and captive portal.
InkyCal
Building an e-ink desk calendar on the InkyFrame 7.3 (Pico 2 W), pulling events over CalDAV and rendering them with MicroPython.
A Simple Power Monitoring Idea
A sketch of a two-part power monitor: a CT-powered remote current sensor plus a mains-powered voltage reference, with questions to answer via experiments.
