Firmware Engineer (Indianapolis)

Sonicu builds wireless monitoring solutions that protect vaccines, labs, and other critical environments. Our cloud platform, SoniCloud, aggregates real-time sensor data and automates alarms and compliance reporting across healthcare and life sciences. We support multiple connectivity paths (Wi-Fi, cellular, Ethernet) with built-in data redundancy, and operate an in-house calibration lab for NIST-traceable sensors.

• Design, implement, and maintain embedded firmware for low-power wireless devices using C/C++ and FreeRTOS
• Develop and optimize drivers and board-support code for peripherals: I²C/SPI/UART/ADC/DAC, sensors, displays, external radios (LoRa, cellular, NFC) and various forms of external memory
• Build reliable wireless features: LoRaWAN class A/C, BLE (GATT), Wi-Fi station/AP, provisioning, roaming, and power-aware duty cycling
• Implement secure bootloaders and OTA update flows; add logging/diagnostics and fail-safe rollback
• Collaborate with hardware, cloud, and mobile teams to ship features end-to-end; participate in code reviews and CI
• Support bring-up, DVT, and manufacturing test scripts; partner with our ISO 17025 lab on calibration/workflows and field reliability
• Profile performance, battery life, and RF behavior; instrument telemetry for real-world observability

• 4+ years professional embedded firmware experience
• Strong C/C++; solid Git workflow
• Hands-on experience with: HAL/LL, toolchains, debuggers like J-Link/OpenOCD, SWD/GDB
• Experience with at least two networking stacks/ communication protocols - from: LoRaWAN, Wi-Fi, BLE, NFC, Cellular
• Comfort with oscilloscopes/logic analyzers, schematics, and reading datasheets
• Clear communication, pragmatic problem-solving, and product instincts

• Experience with ESP32 or STM32 microcontrollers
• FreeRTOS (tasks/queues/timers), lwIP, mbedTLS; secure boot/flash encryption
• LoRaWAN MAC/regions, BLE pairing/bonding, Wi-Fi provisioning/captive portal
• Factory test automation; Python for tools/fixtures
• Power modeling for battery-operated designs
• UX design for e-paper/LCD displays on constrained MCUs (e.g LVGL)
• OTA services, fleet management, and device telemetry design
• Familiarity with quality/compliance contexts common to healthcare & life sciences (e.g., audit-friendly logging/reporting)