Stephen L

Embedded Engineer

Fiverr • Freiberufler

Sep 2025 - Present • 1 yr

- Designed and developed embedded hardware and firmware solutions for client products across IoT, industrial electronics, and consumer devices. - Architected microcontroller-based systems using platforms such as Espressif Systems ESP32/ESP32-S3, STMicroelectronics STM32, Nordic nRF52/nRF53/nRF54, and nRF91 SoC platform, implementing real-time firmware with C/C++ and embedded RTOS frameworks. - Developed embedded Linux-based systems using platforms such as Raspberry Pi, BeagleBone, NXP i.MX series, and Rockchip processors, including BSP customization, driver integration, and application development. - Built and customized embedded Linux distributions using Yocto and Buildroot, enabling optimized and production-ready system images. - Developed graphical user interfaces for embedded displays using LVGL and SquareLine Studio, integrating touch interfaces and responsive UI interactions. - Designed schematics and multi-layer PCBs including power management, sensor interfaces, and communication circuits using professional EDA tools. - Implemented communication protocols such as UART, SPI, I²C, CAN, Bluetooth LE, Wi-Fi, LoRa, Zigbee, 5G, 4G/LTE, NB-IoT, and RFID/NFC for device connectivity and data exchange. - Built firmware architectures supporting OTA updates, device diagnostics, and cloud connectivity for IoT applications. - Performed hardware bring-up, debugging, and system validation using oscilloscopes, logic analyzers, and JTAG debugging tools. - Collaborated with clients throughout the product lifecycle—from concept and prototyping to manufacturing readiness—delivering complete embedded product development solutions. - Supported PCBA design reviews, prototype validation, and production troubleshooting to ensure product reliability and manufacturability.