Firmware Engineer - LoRaWAN/NB-IoT/WIFI

Firmware Engineer Smart Metering & Cellular IoT

Job Summary

We are looking for an experienced Embedded Firmware Engineer with strong hands-on experience in STM32, Smart Metering, DLMS/COSEM, RS485/Modbus and GSM/4G/NB-IoT communication.

The candidate should have experience developing reliable firmware for smart/prepaid energy meters and IoT devices using Quectel, SIMCom or similar cellular modules, with MQTT/cloud connectivity.

Key Responsibilities

• Develop embedded firmware primarily on STM32 using C/C++ and FreeRTOS.
• Develop communication drivers for single-phase, three-phase, prepaid and smart energy meters.
• Implement DLMS/COSEM (IEC 62056) communication, OBIS codes, billing data, load profiles, instantaneous parameters and meter events.
• Develop RS485/Modbus RTU meter communication drivers.
• Integrate Quectel / SIMCom GSM, 4G LTE and NB-IoT modules using AT commands.
• Implement modem initialization, SIM/APN configuration, network registration, TCP/IP, MQTT/MQTTS and automatic reconnection.
• Integrate devices with AWS IoT Core using secure MQTT/TLS communication.
• Develop reliable OTA/FOTA, watchdog, modem recovery and store-and-forward mechanisms.
• Interface with pulse inputs, digital I/O and 4–20 mA analog sensors.
• Debug firmware and communication issues using JTAG/SWD, logic analyzers and serial/protocol debugging tools.
• Coordinate with hardware teams for board bring-up, testing and field troubleshooting.

Required Skills

• 2+ years of relevant Embedded Firmware / IoT / Smart Metering experience.
• Strong Embedded C/C++ and STM32 development experience.
• Hands-on experience with FreeRTOS, UART, RS485, SPI, I2C, ADC, GPIO, timers, interrupts and watchdogs.
• Strong understanding of DLMS/COSEM, IEC 62056 and OBIS codes.
• Experience developing electrical meter communication drivers.
• Experience with Quectel / SIMCom cellular modules and AT commands.
• Knowledge of GSM/GPRS/4G LTE, NB-IoT and LTE-M.
• Experience with MQTT, TCP/IP, HTTP/HTTPS and TLS.
• Experience with AWS IoT Core or similar IoT cloud platforms.
• Understanding of smart/prepaid meters, AMR/AMI and industrial IoT systems.

Preferred Experience

Experience with Secure, HPL, L&T, Genus, Elmeasure or similar energy meters will be an advantage.

Knowledge of ESP32, LoRa/LoRaWAN and ChirpStack is desirable but secondary to STM32, cellular communication and smart metering experience.

Preferred Candidate Profile

Candidates with hands-on experience in STM32 + DLMS/COSEM + RS485/Modbus + Quectel/SIMCom + Smart Metering will be strongly preferred.

Perks & Benefits

• Competitive salary based on experience and skills.
• Opportunity to work on production-grade Smart Metering, Prepaid Metering and Industrial IoT products.