Systems & Engineering Logs

Treating hydration as a line item you must justify, and the three interactions on this site that actually earned their kilobytes.

• performance
• astro
• architecture

Why this interface is built from one-pixel rules and tonal shifts instead of elevation, and how that decision simplifies the CSS system.

• design-systems
• tailwind
• css

Remote environmental data logger that survives six months unattended on a 5 W panel and stores 12 channels of calibrated sensor data in a compact binary log.

// Power

5 W panel · 2×18650 · MPPT charge controller

// Core

STM32L4 in stop mode · 32.768 kHz RTC wake

// Sensors

I²C temperature, RH, soil moisture, UV index

// Storage

8 MB NOR flash · append-only framed log

// Duty cycle

210 ms awake per 60 s sample window

// Runtime

187 days without sun (measured, no blackout)

// Log density

31 bytes/sample after delta encoding

G-code motion planner with optical encoder feedback, dynamic feed-rate correction and a deterministic step pipeline for desktop parametric machining.

// Controller

ESP32-S3 dual-core · FreeRTOS tasks pinned per core

// Planner

Look-ahead trapezoidal velocity profile · 128-block buffer

// Feedback

1000 CPR optical quadrature on all three axes

// Spindle

1.5 kW BLDC · isolated PWM + tachometer input

// Repeatability

±0.025 mm across 300 mm envelope

// Step jitter

1.4 µs σ at 40 kHz step rate

// Recovery

Mid-program resume within one block

Double-DIN instrument console that merges real-time CAN telemetry with decoupled host media processing, without touching the factory wiring harness.

// Compute

Raspberry Pi 5 host · STM32U5 real-time coprocessor

// Firmware

Rust no_std on Cortex-M33 · A/B OTA with rollback

// Bus

CAN 2.0B via TCAN transceivers · 500 kbit/s

// Display

1920×720 LVDS panel · SPI instrument cluster bridge

// Frame jitter

< 1.8 ms worst case over 10M frames

// Cold boot

1.9 s to first rendered frame

// Idle draw

3.1 W (host suspended, cluster live)