Thao N.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

Hi, I'm Thao With 14+ years of experience, I specialize in: - ESP32 / nRF52/ nRF53/ nRF54/ nRF91 / STM32 PCB and Firmware (FreeRTOS, Zephyr) - BLE, Wi-Fi, LTE-M / NB-IoT connectivity - Sensor integration and low power optimization - End-to-end IoT systems (device → cloud via AWS IoT/Thingsboard/EMQX/..., MQTT/HTTP/...) 🔧 Firmware Development - Extensive experience with MCUs: ESP32, STM32, NXP, Nordic (nRF52, nRF5340, nRF54L, nRF91) - Wireless technologies: Wi-Fi, BLE, LoRa - Cellular: 4G / LTE-M / NB-IoT - SIMCOM (SIM800, SIM7000, SIM7600, SIM7020, etc.) - Quectel (BG95, BG96, EC21, EC25, EG25, etc.) - u-blox, Sierra Wireless - QuecOpen development - GNSS integration (u-blox, SIMCOM, Quectel) ⚙️ Peripherals & Systems Interfaces: UART, SPI, I2C, USB, ADC, PWM, CAN, DALI 2 Industrial communication: RS485, Modbus RTU Sensors: Temperature, humidity, pressure, gas (CO, SO2, NO2, O3), dust, pH, EC, light ☁️ IoT & Cloud Integration AWS IoT (MQTTs, HTTPs, provisioning, S3) EMQX, HiveMQ Thingsboard End-to-end IoT system integration 🧠 RTOS / Platforms FreeRTOS Zephyr RTOS Arduino framework 🔊 Other Experience Alexa-enabled devices and audio streaming systems 🛠️ Hardware Design Schematic design: Digital, Analog, Power electronics PCB design: 1–4 layers, 3D layout Tools: KiCad Manufacturing: JLCPCB, PCBWay I would be happy to discuss your project and help you build the best possible solution. Best regards, Thao Nguyen