I build end-to-end embedded IoT systems — from firmware up through cloud connectivity and the tooling around them. Transitioning deeper into embedded/IoT engineering, with a focus on connected hardware.
- 🔭 Building Schatzograph — a full FreeRTOS multi-driver ESP32 firmware project (see below)
- 📡 Deep in Bluetooth Low Energy, ESP32, and MQTT/protobuf pipelines
- 🌱 Currently learning: advanced BLE patterns, CI/CD for embedded systems
My primary portfolio project: an ESP32-based embedded system built around end-to-end IoT ownership, from hardware bring-up to CI/CD.
- Firmware: Full FreeRTOS multi-driver architecture — HTU21, PCF8574, PN532, DS3231, SD card, INA219
- Connectivity: MQTT with
nanopbProtobuf serialization, plus a custom Python decoder - Storage & networking: LittleFS, NVS, FTP server driver, ESPAsyncWebServer with cookie-based session auth
- Power: Debugged and resolved a power-chain issue where the MT3608 sagged under ESP32 boot current, moved to a TPS63020 buck-boost converter
- CI/CD: Six-stage GitLab pipeline (lint → build → docs → changelog → release → quality-gate) with firmware metadata injection, running on a self-hosted Raspberry Pi 4 runner
A Windows desktop BLE scanner and terminal tool.
- Async BLE scanning built on
bleak - Desktop UI with
ttkbootstrap - Packaged as a standalone
.exevia PyInstaller, with a fully automated GitHub Actions build pipeline (dynamic versioning, artifact publishing)
A wireless, IR-remote-controlled power switch project.
- ATtiny85 (Digispark) + ESP32 + VS1838B IR receiver driving a bistable relay
- Solved a real-world Windows driver issue (libusb-win32 via Zadig) blocking firmware uploads
Embedded: ESP32 · FreeRTOS · Arduino Framework · I²C / SPI / UART · BLE · MQTT · PlatformIO
Hardware: KiCad · Power electronics (LiPo, TP4056, buck-boost) · Logic analyzer debugging
Desktop / Backend: Python · Bleak · PyInstaller · Tkinter
Mobile: React Native · Expo
Tooling: Git · GitHub Actions · GitLab CI · Docker · Linux
- GitHub: @polymert
"Per aspera ad astra"