Peter Hajduch / Vanderhell

Software and
embedded systems
developer_

I build industrial software, embedded C libraries, firmware infrastructure and developer tools with a focus on predictable behavior, clear failure modes and practical integration with real hardware. My work spans C, C++, C#/.NET, microcontrollers, industrial communication, storage, diagnostics and reliability-oriented systems.

mcu:/firmware $
What I work on

Software from industrial applications to constrained firmware

I work across application software, embedded systems and the infrastructure between them. The common goal is software that is understandable, testable and practical to integrate.

Industrial software

C# and .NET tooling for real systems

Desktop and internal business tools, industrial data processing, SQL-backed applications and integration layers that connect software with production processes.

Embedded systems

C and C++ firmware for MCU targets

Embedded C99 libraries, microcontrollers, ESP32 work, deterministic memory and execution behavior, and hardware abstraction for constrained environments.

Reliability and diagnostics

Failure handling you can inspect

Runtime safety, persistent evidence, logging, recovery behavior, storage integrity and explicit system contracts that can be tested rather than assumed.

Communication and tooling

Industrial protocols and host tools

Industrial communication, Modbus and device integration, host-side utilities, diagnostics and development tools that bridge embedded devices and desktop systems.

Design biasPredictable behavior, small integration surfaces and explicit failure modes
DependenciesMinimal where appropriate. C99 embedded libraries can stay lean without pretending every part of the stack is heap-free
ProofTests and evidence before claims. Practical tools over demo-only abstractions
My project family

LOX - Liquid Oxygen

LOX is my family of embedded and systems-software projects. It brings together focused libraries for storage, boot, safety, diagnostics, permissions, sequencing and resource control under one technical identity.

LOX - Liquid Oxygen - Embedded Systems

Peter Hajduch creates LOX - a technical brand for embedded systems work

The LOX family

Deterministic building blocks
for constrained firmware

These are the LOX projects that grew out of Peter Hajduch's embedded and systems work: C99 libraries built around storage, safety and resource control with predictable memory and a small integration surface.

loxdb / flagship MIT core

Deterministic embedded database for MCU & edge

KVTime-seriesRelational tables

Three storage models behind one C99 API. One allocation at lox_init(), fixed RAM budgeting, zero external dependencies, RAM-only or storage-backed operation, optional WAL-backed persistence and recovery, embedded-first storage HAL. Intentionally narrower than SQLite - built for dataloggers, controllers and small edge runtimes.

Open loxdb detail
loxdb_pro Commercial

Production modules around the loxdb core

The PRO layer for embedded products that need more than storage: security and integrity, runtime safety validation, metrics and alerting, policy gates, quotas and retention, backup and schema migration, replication and transport framing, OTA planning with rollback hooks, CLI tooling, and optional SD/NAND-FTL adapters. The public repository contains API-level documentation; the implementation is not published.

Open loxdb_pro detail
loxboot C99

Zero-heap bootloader core

A/B slot model, boot state validation, UART update transport, rollback-oriented boot flow, and a clean platform handoff boundary - without heap allocation.

Open loxboot detail
loxguard C99

Guard Blocks for embedded C

Explicit execution boundaries around risky code - parsers, protocol handlers, recovery-sensitive routines. Failures become structured runtime evidence instead of a bare watchdog reset.

Open loxguard detail
loxalarm C99

Deterministic alarm-state core

The full alarm lifecycle for firmware: on/off delays, latching, acknowledge flow, shelving, reason flags, and snapshot/restore support.

Open loxalarm detail
loxseq C99

Power-loss-aware step sequencer

Checkpointed step progress with a reboot recovery/resume policy per step - multi-step procedures that survive a power drop mid-step.

Open loxseq detail
loxperm C99

Permissive / interlock evaluator

Heap-free evaluator with explainable deny mask, first-out detection, qualifier times, latching, and maintenance bypass. When firmware says no, it tells you why.

Open loxperm detail
loxbudget MIT

Deterministic admission control

A heap-free pre-flight gate in front of risky firmware work: MQTT publish, OTA, flash writes, log bursts. Deterministic check / enter / leave decisions per operation profile.

Open loxbudget detail
loxc Experimental

Trainable C99 text codec

For developers who know their data: train a codec table from representative MQTT payloads, telemetry or logs, export it, and decode with predictable table-driven logic. Not a gzip competitor, not encryption - a compact encoding path for domain-specific text.

Open loxc detail
the whole family GitHub

9 LOX projects - and counting

Every LOX library follows the same contract: C99, predictable memory, small integration surface, clear failure modes, and tests before claims. Browse all repositories on GitHub.

View all repositories ->
micro-toolkit

Modular C99 libraries -
#include and go

A collection of small composable libraries sharing one philosophy: no heap, no dependencies, no code generation.

micro-toolkit detail page ->

More work

From bare metal to the desktop

Bare-metal safety & diagnostics

  • panicdumpCrash dumps for Cortex-M3/M4 - capture on fault, decode offline
  • MCU-Malloc-TrackerDeterministic heap diagnostics for bare-metal MCUs
  • nvlogPower-loss safe append log for FRAM / EEPROM / NOR flash
  • deferAutomatic resource cleanup for C via DEFER() macro
  • cguardScope guards and result types for C
  • safemathOverflow-checked arithmetic and buffer sizing helpers
  • microcryptSHA-256, HMAC-SHA256, AES-128 ECB/CBC
  • microdhMinimal X25519 key exchange for embedded systems
  • microtestSingle-header C test framework

Industrial IoT & protocols

  • IOBusMonitorMulti-protocol desktop tool for Modbus TCP/RTU and Siemens S7 PLCs (C#)
  • RTULogSuiteModbus RTU logging toolchain - ESP32 firmware + Windows visualization
  • uMeshLightweight mesh networking stack for ESP32 over raw 802.11
  • num8-lupLow-bandwidth update propagation protocol for constrained links
  • num8O(1) membership engine for 8-digit numbers using a fixed bitset
  • IronFamily.FileEngineBinary IoT file engines: config, structured logs, firmware packages

Desktop, .NET & hardware

  • MultiGpuHelperC# library for scheduling compute workloads across multiple GPUs
  • CrudFrameworkLightweight CRUD framework for .NET, EF Core, SQLite / SQL Server
  • securebox-hwSecure hardware password manager concept on ESP32-S3
  • Pragotron-ControllerMinute-impulse controller for a Pragotron stepper clock
Collaboration

Working with firmware, MCUs
or industrial devices?

Contact Peter Hajduch directly for embedded C testing, MCU validation, industrial and edge systems, storage and power-loss behavior, reliability and diagnostics, or C#/.NET and host-side tooling where relevant.

embedded C testing MCU hardware validation storage & power-loss testing reliability & diagnostics industrial / edge use cases examples & integration feedback

Support the projects

If the LOX family or micro-toolkit saves you time in a real project, you can support continued development by getting in touch. That helps cover hardware for validation and testing.

Support by email