Firmware engineer with 5+ years building production-grade embedded systems for medical devices, industrial IoT platforms, and smart wearables. I work across the full stack — from bare-metal MCU bring-up and RTOS/bootloader design to wireless protocol implementation (BLE Mesh, Thread, LoRaWAN, ESP-NOW, CAN, Modbus), analog front-end circuits, and secure OTA delivery.
- 🏥 Currently building safety-critical firmware at Caropet Technologies (medical devices)
- ⚡ Achieved sub-500nA sleep current on BGM220-based BLE wearables in production
- 🌐 Deployed firmware across 2500+ devices in the field
- 📡 Running 5 active LoRa hubs for BeetleGuard environmental monitoring
- 🔐 Built a signed, rollback-safe MCUboot OTA pipeline (Ed25519, image confirm/revert) from scratch
- 🧩 Shipped a small preemptive RTOS kernel (priority scheduling, mutexes, semaphores) for Cortex-M, with a host-testable portable core
MCUs & SoCs
Languages
RTOS & Firmware
Wireless & Protocols
Tools
RTOS, Bootloaders & Protocol Stacks
| Project | Domain | Description |
|---|---|---|
| secure-ota | Bootloader/Security | MCUboot-based signed OTA (Ed25519), rollback-safe image confirm/revert, SMP over BLE |
| tinykernel | RTOS | Preemptive priority-scheduled kernel for Cortex-M — mutexes, semaphores, host-testable core |
| modbus-rtu | Industrial Protocol | Modbus RTU master/slave stack over RS-485, CRC-16, host-testable frame parsing |
| lorawan-node | LPWAN | LoRaWAN end-node (Class A), OTAA join, AES-CMAC/CTR crypto, duty-cycle compliant |
ESP32 / ESP-IDF IoT Batch
| Project | Domain | Description |
|---|---|---|
| espnow-mesh | Mesh Networking | Multi-hop ESP-NOW flood-routing mesh with dedup/TTL, no Wi-Fi AP required |
| esp-ble-mesh-light | BLE Mesh | Standards-compliant Generic OnOff/Level server node, PWM dimming curve, transitions |
| esp-ota-https | Secure OTA | HTTPS OTA over dual-slot (two-OTA) partition table, TLS cert pinning |
| esp-thread-node | Thread/802.15.4 | ESP32-C6 OpenThread end-device, CoAP-lite on/off actuator over UDP/IPv6 |
| esp-can-gateway | CAN Bus | CAN-to-JSON telemetry gateway, TWAI driver, signal decode over MQTT |
| esp-modbus-gateway | Industrial Protocol | Modbus RTU-to-TCP/MQTT gateway bridging RS-485 field devices to the cloud |
Medical & Sensing
| Project | Domain | Description |
|---|---|---|
| nRF52840 PPG — MAX30102 | Medical | SpO₂ + heart rate via MAX30102, I²C driver, ratio-of-ratios SpO₂, BLE GATT notify |
| ESP32 IoT Data Logger | Industrial | RS485/Modbus, 4–20mA (ADS1115), MQTT QoS-1 alarms, ESP-IDF |
| BLE Beacon Scanner | IoT | Custom advertising payload decoder, live fleet table, missed-packet detection |
Tools & Personal
| Project | Domain | Description |
|---|---|---|
| UART Debug Tools | Tools | Serial reader, binary packet parser, real-time plotter, calibration tool |
| Modern Flame Diya | Personal | ATtiny85 WS2812 flame animation, capacitive touch, custom PCB |
| Portfolio | Web | Professional firmware engineer portfolio — live at saikumar-mandaji.github.io |
- 🔬 Medical device firmware on Si Labs BGM220 and STM32 at Caropet Technologies
- 📶 Working with nRF54L15 on nRF Connect SDK — BLE 6.0 firmware on Cortex-M33
- 📡 Expanding the ESP-IDF IoT batch (BLE Mesh, Thread, CAN, Modbus, LoRaWAN, secure OTA) with real-hardware BOMs for every project
- 🐍 Python tooling for UART-based embedded device analysis and automated calibration