Field notes
Notes from client and product work in embedded systems, integration and modernisation. Each one is about a specific job, what I did and what came out of it.
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The RockBLOCK 9704 on Zephyr, and the pin wired upside down
Monday, October 26, 2026 in Field notes
A microcontroller on my back step sent 16 bytes through an Iridium satellite. The message was “Stamp-C3 says hi”, and it was in Cloudloop about ten seconds after the shell command that sent it. The Zephyr module that got it there is now …
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I built a LoRa analyser because I was sick of guessing
Friday, September 04, 2026 in Field notes
Debugging a LoRa link used to go like this. A node stops reporting, so I swap the antenna, move the gateway and drop the spreading factor. Something improves, or it doesn’t, and I have no idea why, because I cannot see the band. So I built the …
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Zephyr is the DOS-to-Linux moment for embedded
Sunday, August 16, 2026 in Field notes
I’ve written embedded firmware for a long time, on AVR, ESP32, nRF52 and RP2040, and mostly the default was bare metal or a small superloop. It worked. It was also the DOS era of microcontrollers: you own the whole machine, you write every …
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We open-sourced our Antarctic wave buoys
Friday, July 03, 2026 in Field notes
For over a decade I built and maintained the firmware for the Waves In Ice buoys, instruments that are placed on Antarctic sea ice, freeze in, and report wave motion back over Iridium satellite for months at a time. The data from the earlier …