en/blog
Notes from
the bench.
Field notes, bring-up lessons and the occasional high-voltage reminder — written by the engineers who probe the boards.
ESP32 OTA in the field without bricked nodes
IoT · Firmware
Dual partitions, rollback flags and the pre-flash checklist we use before pushing firmware to devices on poles.
DC motor stall detection that survives a jam
Embedded
Current sense, timeout windows and firmware interlocks for a gearbox that will eventually bind.
Measuring sleep current without fooling yourself
Power electronics
A practical sequence for measuring deep-sleep current on a cellular tracker — and the traps that make a good board look broken.
GNSS antenna layout on a cramped PCB
RF
Keep-out, ground stitching and why the GNSS port wants its own world — lessons from a tracker that had to fit in a matchbox.
Introduction to Tesla coils
Power electronics · High voltage
A Tesla coil is a resonant air-core transformer. This is the long way around: what resonance actually does, why a spark gap starts one, and why a transistor bridge has to be told the frequency.