Mqtt, Bluetooth, C, Zigbee, Uart, Spi, I2c, Ble, 1-Wire, Wi-Fi, ARM Cortex-M microcontroller development, Modbus TCP, Electronic Circuit Design, Regulatory Compliance, Ultra-low power design, Pcb Layout, Industrial communication protocols, Linux-based systems, LoRa, Analog and digital sensors, Zigbee protocol stack, Cloud APIs, Embedded firmware development