JOB DESCRIPTION
Senior IIoT Firmware Engineer

Location:
S.
B.
Road Pune, On-site Industrial IoT Gateways | Smart Sensors | Edge Telemetry Role Overview We are looking for an experienced firmware engineer to build industrial IoT gateways, smart sensors and edge-telemetry units. The role combines firmware development for industrial equipment interfaces (including Modbus and CAN), local data processing, and dependable telemetry delivery to cloud infrastructure over BLE, Wi-Fi, 4G LTE and GPRS. A key focus is maintaining data integrity and reliable connectivity in bandwidth-constrained, power-sensitive and electromagnetically noisy industrial environments.

Key Responsibilities
1. Wireless Connectivity and Network Management
• Integrate wireless communication modules and technologies, including Wi-Fi, Bluetooth Low Energy (BLE 5.0+), 4G LTE and GPRS/2G fallbacks.
• Build resilient network-management logic for automated network switching, signal-strength optimization, reconnection state machines and failover paths.
• Implement secure over-the-air (OTA) firmware updates over cellular and Wi-Fi, including boot validation and rollback protection. 2. Industrial Protocols and Edge Telemetry
• Develop master/slave communication engines using Modbus RTU over RS485/RS232 and Modbus TCP to collect telemetry from industrial energy meters, PLCs and variable-frequency drives (VFDs).
• Translate machine registers—including Modbus holding registers and CAN frame IDs—into structured, serialized payloads such as JSON.
• Build optimized MQTT clients that manage QoS levels, persistent sessions, keep-alives and retained messages to stream edge data securely to AWS IoT Core, Azure IoT or custom Mosquitto brokers. 3. Edge Data Processing and Storage
• Implement local buffering and timestamped logging using SQLite,



SD cards or BBRAM to reduce data loss during cellular or Wi-Fi outages.
• Optimize power consumption and bandwidth usage in cellular/GPRS deployments through data compression and deadband polling strategies.
• Develop edge-computing logic for local decision-making, rapid filtering, real-time alert triggers and safe-state management. 4. Firmware Architecture and Microcontroller Development
• Build modular, multithreaded bare-metal or RTOS-based firmware, including FreeRTOS, for 32-bit platforms such as STM32, Renesas RA, ARM Cortex, NXP and ESP32.
• Manage real-time peripheral tasks alongside network transactions, including UART/SPI/I2C buses, timers, watchdog timers and low-level ADC interfaces. Technical Skills Programming: Embedded C, C++, and Python or shell scripting for internal automation and testing tools. Industrial and Field Protocols: Modbus RTU/TCP, CAN Bus (SocketCAN, bxCAN, J1939, UDS), RS485 and RS232. IoT and Networking: MQTT, HTTPS, TCP/IP socket programming and JSON serialization. Wireless and RF: 4G LTE/GPRS cellular AT commands, Wi-Fi (802.11) and BLE profiles, services and advertising. Operating Systems and Microcontrollers: FreeRTOS, STM32, ARM Cortex-A/M processors and ESP32 (ESP-IDF). Debugging Tools: Wireshark, PCANView/Vehicle Spy, logic analyzers, GDB and AT-command terminals such as Tera Term. Security: TLS 1.2/1.3, MQTTS (secure MQTT), cryptographic device authentication and X.509 certificate handling. Qualifications and Experience
• 4–6 years of experience in embedded software or firmware design, including at least 2 years focused on deploying networked IoT products in production industrial environments.
• Bachelor’s or Master’s degree in Electronics and Communication Engineering, Electrical Engineering, IoT or a closely related discipline.
• Experience with remote field-monitoring gateways, smart energy grids, heavy industrial instrumentation or environmental telemetry systems.

📌 Embedded Firmware Engineer (India)
🏢 Repos Energy
📍 India