steeman.be

An attempt to read a Platinum 3100S solar inverter directly over its proprietary RS485 protocol with an ESP32. It has not cracked yet, so the full dataset is published for anyone who wants a go.

Predicting where a weather balloon’s radiosonde will land from its own radio telemetry alone, testing it on a real flight, and backtesting it against years of launches from Uccle.

An encrypted offsite backup on a Raspberry Pi at a relative’s house, reached over Tailscale, whose LUKS key never leaves home. Covers the threat model, the boot unlock and a dead-man’s switch.

An ESP32-C3 that controls a RunCam Thumb over its serial protocol: start recording the moment power arrives, and check and control the camera from a web page on its own Wi-Fi access point.

Keeping the Belgian capacity tariff down with three Marstek Venus E batteries and Home Assistant: how the kwartierpiek is billed, the settings that matter and two traps I nearly fell into.

Getting a second-hand Solar-Log 500 to read my Platinum 3100S solar inverter over RS485 and feed its production into Home Assistant. The wiring polarity and the firmware were the real obstacles.

Turning an ESP32 Cheap Yellow Display into a desk panel with ESPHome that shows the house’s power use and opens the door or garage with a tap. Four gotchas along the way.

Home Assistant sensors for the five-hour and weekly usage limits of my Claude and z.ai coding plans, including reverse-engineering the z.ai API and a dashboard.

Keeping Claude Code’s settings, skills and project context in sync between a desktop and a laptop with a Synology NAS, symlinks and Syncthing, plus split changelogs.

Building a TiltBox, a small wooden game console with an 8x8 LED matrix that you play by tilting it. ESP32-C3, an ADXL345 accelerometer, a home-made front panel and a few contributions back to the project.

Why I moved from pasting into ChatGPT to an AI toolkit that does the work: Claude Code in the terminal, cheaper GLM models from z.ai, plan and API pricing compared, and a switcher between backends.

Seven screens across three computers on one desk, controlled with a single keyboard and mouse through InputLeap. The layout, a custom monitor stand and the cable management.

A Docker container on an RTX 3090 that transcribes audio locally with Whisper, labels who said what, fixes names with an LLM pass and can write a summary. No audio leaves the machine.

How labelling my parts storage grew from round Herma stickers to a Dymo LabelWriter driven by a LibreOffice spreadsheet and macro, including a long fight with label orientation.

The Claude Code setup I settled on after months of daily use: a dedicated machine, config synced across computers, a model selector for three backends, session recording and a custom status bar.

The backup system for my homelab server, triggered by a failing disk: Borg with encrypted repositories, a local disk, a NAS mirror and an offsite Raspberry Pi, with retention and alerts.

Building and flying a PML Intruder for my Tripoli Level 1 certification at Exloo in March 2026: the build, the simulation, the recovery and what the flight log really shows.

The hardware and software behind running 32B language models at home: why VRAM decides everything, the full build, Ollama, tuning from 5 to 35 tokens per second, and how well it actually works.

How Claude Code brought this site back after eleven quiet years: moving from Nanoc to Hugo and Blowfish, migrating every post, keeping old URLs working, and deploying.

Bed buttons and wake-up lights for the kids, driven by VSCP: the lights turn green at a set time on weekdays and later at the weekend. The decision matrix rows that make it work.

Firmware v1.20 for the Mespelare node adds the Control TurnOn and TurnOff actions, needed for the kids’ bed buttons and lights. Shows where the new code hooks into the decision matrix.

Adding computer control to a Ham IV antenna rotator for satellite tracking, using K3NG’s rotator code on an Arduino Pro Micro with an LCD, and calibrating the heading.

Replacing the blown backlight bulb of a 1981 Ham IV rotator controller with a strip of LEDs, a diode, a resistor and a capacitor.

Sending VSCP events at set times from the daemon’s decision matrix, for example to turn off every light that was left on at night. Each field of the DM row explained.

A charger that tops up five single-cell LiPo or Li-ion batteries at once from one 6 to 20 V supply, built around Microchip’s MCP73831 charge controller. Schematic and board included.

What is inside the 10 euro REX C100 PID temperature controller from eBay, in photos.

Switching lights on the VSCP bus from a web page, with buttons and status indicators that talk to the VSCP daemon over websockets. Includes the decision matrix and daemon configuration.

Setting up an openHAB development environment on Ubuntu 14.04: the Git clone, Java, the Yoxos installer, Maven and a test build.

A short video tour of my VSCP-based home automation system.

My checklist for configuring each Mespelare node as it goes into the house: loading the register template, mapping inputs to outputs and setting the LED and output control registers.

Replacing the broken pull cord on a Yamaha 9.5A outboard, including how to handle the recoil spring safely. Documented in reverse order of disassembly.

A slow PWM controller on an Arduino with a potentiometer and a solid-state relay, to set the heating power of a Weck kettle when boiling wort.

Making a missing slotted bushing for a Hobbymat MD65 lathe without a mill, by mounting a grinder on the lathe to cut the slot.

An automatic fertiliser doser for the aquarium, made from a 230 V mechanical timer whose slow geared motor turned out to be just right for driving a syringe.

A doorbell built on a Raspberry Pi with a camera that e-mails a photo of whoever rings. Power supply, button wiring, the Python script and mounting.

Feeding the plants in my indigenous aquarium with the Estimative Index: dosing macro and micro nutrients on a schedule instead of measuring them with test kits.

Installing vscp_software on a Raspberry Pi, every command with its output, from package updates and dependencies to building the software.

My notes for setting up a Raspberry Pi B+ as a VSCP daemon server and doorbell: static IP, hostname, NAS share, Samba and VNC.

Switching the Hasselt VSCP firmware from its non-standard 250 kbps CAN bus speed back to the 125 kbps everyone else uses. A small register change in vscp18f_init().

Making a Mespelare VSCP node switch its own relays from its own buttons, so the lights keep working when the bus is down. Covers the code hook, a configurable output mapping and output modes.

Fixing a hang in sendCANFrame() when VSCP Works reads many registers at once, with a one-second send timeout.

Changing the Hasselt firmware’s Timer0 tick from 10 ms to 1 ms for the Mespelare node, and updating the code that relied on the old period. Includes a scope capture of the result.

A new Pulse action for the Hasselt firmware, so the decision matrix can drive the pulse relays in my house. Firmware, MDF and decision matrix changes.

Turning a domestic oven into a PCB reflow oven with the Hobbybotics reflow controller firmware: PID temperature control, solder profiles, a display and a PC application.

How VSCP register addressing works: how registers in the MDF map onto the node’s application space and how the firmware stores them.

A walk through the structure of a VSCP Module Description File, from the XML header and module information to the registers, using the Mespelare module’s own MDF as the example.

A Siemens condenser dryer kept reporting a full water tray when it was empty. A very thorough clean fixed it, at a fraction of the repair quote. Photos of every step.

Migrating the Mespelare firmware from Microchip’s retired C18 compiler to XC8, following the migration guide section by section.

Bringing a bricked PICkit3 back to life by reprogramming its firmware with a PICkit2.

A quick plywood cabinet that gives my Nikon D3000 a fixed place on the workbench, with a USB cable routed in so it can stay connected.

A final prototype, Mespelare v9, to make sure the board design is right before ordering production PCBs. The fixes from v6, the tests and the firmware.

My roadmap for a VSCP home automation system, from the toolchain and testing Kurt’s boards to the Mespelare node, production and a reflow oven.

Updating the Mespelare node to the latest vscp_firmware from GitHub, and the compile errors and changes that came with it.

A small PIC 16F648A APRS tracker running the OpenTracker firmware, with a 300 mW HX1 transmitter on the back and a header for a GPS module. Hand-solderable 1206 parts.

A DumpEEPROM() routine that prints the node’s EEPROM over the serial port, to check what VSCP Works actually wrote. Needed because every published Hasselt MDF turned out to be wrong.

A cheap plywood cabinet that stores SMD and through-hole parts in small screw-cap yoghurt-drink bottles, each with a label on the cap.

Adding a serial debug port to the Hasselt VSCP firmware, so you can watch variables and program flow while the PIC runs. One #define switches all the debug output on or off.

Configuring the Mespelare node’s decision matrix through its registers so it reacts to events on the VSCP bus.

A function-by-function walk through the Hasselt VSCP firmware that the Mespelare node is based on, from the interrupts and main() to event handling, with a program flow diagram.

Bringing my childhood aquarium back as a low-cost, low-maintenance tank with local plants and fish, in the basement workshop for the kids to enjoy.

Getting the USB2CAN interface running with VSCP on Ubuntu: the driver, the VSCP daemon and testing the bus with VSCP Works.

Printing a different text on every label from an Excel list with Herma Label Designer’s database import, for labelling component jars.

Installing, configuring and testing the VSCP daemon on Windows, so several applications can share one bus interface. Includes the catches I ran into.

A sliding table for my table saw that always runs square to the blade, replacing a fence that never stayed parallel.

Labelling homebrew on the bottle cap instead of the bottle, with round Herma 4386 stickers printed from Herma’s free Label Designer. Readable in the crate and nothing to scrub off afterwards.

A bigger table with a sliding precision fence for a cheap pillar drill, made from scrap multiplex and rubberwood, for drilling repeatable holes.

Modding a PlayStation 1 with a programmed PIC mod chip so it plays copied discs: how the mod works, opening the console, programming and installing the chip, and testing.

A small change that lets the Blast bottle rinser click onto a standard hose quick-connector instead of being screwed onto the tap. In Dutch.

Step by step: turning a 50 MHz Rigol DS1052E oscilloscope into its 100 MHz DS1102E twin with a firmware hack, then upgrading the firmware and calibrating the scope.

A reading list for VSCP beginners: the protocol introduction and specification, VSCP Works, filters and masks, the decision matrix and setting up the daemon on Linux.

Adapting the Hasselt code to the Mespelare board: pin assignments, the MDF location and setting the registers, then running it on the hardware for the first time.

Compiling kurtsidekick’s Hasselt firmware for the first time in MPLAB X, as the starting point for the Mespelare firmware: target settings, preserving EEPROM and programming the test board.

All the beer recipes I have brewed so far, as spreadsheets, with the ones worth brewing again in bold.

The hardware and software I use to learn and develop for VSCP: MPLAB X, a PICkit 3, a USB2CAN converter and VSCP Works.

The Mespelare VSCP node: a CAN bus board that reads a Niko six-button panel, drives its LEDs and six relay outputs, and breaks out the rest of the pins for expansion boards.

How the old version of this site was made: articles written in Markdown, compiled into a static site with Nanoc, with categories, image thumbnails and self-hosting.

Who writes this site and why: a personal, unpolished collection of technical projects for people who stumble on them with the same interests. Also covers the technical side and the licence.

A USB CAT interface for the Kenwood TS-50 made from a cheap USB-to-TTL adapter, and how to connect it to the radio.

A rack under the basement stairs that holds 23 cases of beer, built from cheap pine and sized for Duvel crates. The cases sit half on their side so every bottle can be reached without lifting a crate.

Turning a pillar drill into a sturdy bottle capper, with a lathe-turned capping head and a bottle support that sets the height.

A small automated brewery for 28 litre batches, built around a Weck kettle and a BrewTroller controller as a cheaper alternative to a Braumeister. A photo series of the build.

A two-roller malt mill built as a metalworking exercise, with an adjustable gap so the grain is crushed fine while the husks stay mostly whole for lautering.

Building the MiniMost, a small plywood boat from a 1960s Popular Mechanics design, to put a second-hand 2 hp outboard to use. Build log in Dutch.

A stir plate for growing yeast, built around an 80 mm computer fan with PWM speed control, plus thermostat-controlled heating, in a two-level case.

A floating platform with a sofa bed, a tent and a barbecue that we built, took onto the river and lived on for a few days of fishing. Mostly photos.

The third firing of the Ballistic Evaluation Motor, run to check the fixes from test 2, with the load cell now on a steel plate. Report in Dutch with data, sound and video.

The second firing of the VRO Ballistic Evaluation Motor, with a wider throat and a new igniter tube after the first test failed to light. Observations, audio, video, measured data and the fixes for next time.

An integrated measuring system for static motor tests on the Ballistic Evaluation Motor: load cell, pressure sensor and break wires read into a computer. In Dutch.

A load cell amplifier for static rocket motor tests, with the ADC on board, that plugs into USB and records the thrust curve for analysis in a spreadsheet.

A compact four-channel rocket timer built around a PIC 16F88. It detects lift-off with an accelerometer or a reed switch and fires up to four pyro charges at programmed intervals, independently or in groups.

A home-built serial CAT interface for the Kenwood TS-50 so logging software can follow band and mode changes. Superseded by the USB version.

The story behind the photo on my QSL card: the Hydrocopter that carried me across the ice to Holmön island (EU-135) for a DXpedition in Sweden.