Ramu Roy

// 01 — selected work

Shipped firmware, distros & deployed systems

FIG. 01

Active dev

eOS

A custom Yocto Linux distribution for the Raspberry Pi 5

eOS is a from-scratch embedded Linux platform built on Yocto/OpenEmbedded for the Raspberry Pi 5 (16GB). It pairs A/B RAUC OTA updates with an MQTT service bus, SQLite persistence, a Qt6/QML local UI, a Rust sensor-fusion framework, and a fully on-device voice subsystem.

YoctoBitBakeOpenEmbeddedkasRAUC A/B OTAsystemdD-BusMosquitto MQTTSQLiteQt6/QMLRustRaspberry Pi 5

Platform: Raspberry Pi 5 (16GB)
OS: Yocto / OpenEmbedded
Update: A/B RAUC OTA
Bus: MQTT · D-Bus
Stack: Rust · Qt6/QML · SQLite

Engineering detail

Authored and extended Yocto recipes (.bb/.bbappend) across the meta-eos layer, with BitBake PR bumps, AUTOREV pinning, and IPK packaging for incremental on-device deployment
Work across the Linux subsystem stack: systemd unit design, D-Bus interfaces (org.eos.Config1, org.eos.RoomCommands1, org.eos.RoomAggregates1), a Mosquitto MQTT broker hardened with TLS and ACLs, and SQLite schema migrations with multi-writer concurrency tuning
Wrote a generic Rust RoomAggregator framework for per-room sensor fusion across thermal, mmWave radar, air-quality, ambient-light, and PIR motion inputs, with D-Bus calibration and SQLite-backed persistence
Owned the build and deploy flow end to end: extended kas orchestration plus an in-house eos-build CLI, cross-compilation, WIC image builds, bmaptool SD flashing, and RAUC A/B verification

Elipse · no public repo

FIG. 02

Deployed

Industrial Anti-Collision System

UWB crane anti-collision safety system, deployed at Tata Steel BlueScope

A real-time industrial Anti-Collision System for crane operations, built during an embedded internship at Radiogeet and deployed at Tata Steel BlueScope. It uses UWB proximity detection and zone-based safety logic to trigger industrial outputs that prevent hazardous crane movements.

ESP32-S3FreeRTOS dual-coreESP-IDFUWBESP-NOWMODBUS RTURS485STM32LoRa

MCU: ESP32-S3 (dual-core)
Sensing: UWB ranging
Links: ESP-NOW · RS485
I/O: Masibus 8-ch relays
Result: Live @ Tata Steel BlueScope

Engineering detail

Architected ESP32-S3 dual-core firmware: core 1 runs time-critical UWB distance measurement while core 2 handles zone calculation, system logic, and an embedded web UI
Linked nodes over ESP-NOW for low-latency peer-to-peer communication
Drove an 8-channel industrial relay system via MODBUS RTU over RS485 to Masibus DO cards
Extended the platform with STM32 work: AHT10 and ADS1115 interfacing, timers and ADC/DAC, 2/4-wire RS485, LoRa links, and Masibus DI/DO/AI/AO cards

REF → github.com/ramuroy/Industrial-Anti-Collision-System

FIG. 03

Part of eOS

On-Device Voice Subsystem

A fully on-device, Rust voice pipeline: wake word → STT → TTS

The voice layer of eOS, built end to end in Rust to run entirely on-device. It chains a transfer-learning wake-word detector, multi-mic best-source fusion, Whisper speech-to-text, and Piper text-to-speech, with async-Rust barge-in for natural interruption.

RustPyTorchONNXtractWhisper STTPiper TTSKWStransfer learningmulti-mic fusion

Runtime: tract (pure Rust)
Wake word: transfer-learned KWS
STT: Whisper
TTS: Piper
Result: 100% on-device

Engineering detail

Trained a transfer-learning wake-word detector using Google's speech_embedding backbone with a PyTorch head, exported to ONNX and run on the pure-Rust tract runtime
Implemented multi-mic best-source fusion across ESP32 satellite microphones to pick the cleanest audio
Integrated Whisper for speech-to-text and Piper for text-to-speech, all running locally on the device
Built async-Rust barge-in so the system can be interrupted mid-response

part of eOS

// selected on github

VIEW ALL ON GITHUB

RTOS Weather Logger Jan 2025

An ESP32 weather logger using DHT11, FreeRTOS, and Blynk.

ESP32FreeRTOSDHT11

Firmware/RTOS repo

Solar Track Mar 2025

Dual-axis sun tracker — four shaded LDRs steer two servos (azimuth + tilt) to keep a panel facing the sun.

ArduinoServoLDR

IoT repo

Object Detection over SPI

Real-time object detection over SPI between ESP32 and Arduino with an IR sensor.

ESP32ArduinoSPI

IoT repo

Transformerless Power Supply Aug 2024

A 220V AC → 5V DC transformerless power supply designed in KiCad.

KiCadPCB

Hardware/PCB

LM2596 5V Buck Converter PCB Dec 2024

An efficient switching regulator board built around the LM2596.

KiCadLM2596PCB

Hardware/PCB repo

FreeRTOS Multitasking LEDs

A C/FreeRTOS demo running concurrent LED tasks.

CFreeRTOS

Firmware/RTOS repo

5V → 3.3V Voltage Regulator PCB Oct 2024

A 5V → 3.3V regulator board based on the AMS1117-3.3.

KiCadAMS1117PCB

Hardware/PCB repo

Servo Tester (NE555) Sep 2024

An astable NE555-based PWM servo tester.

NE555PWMPCB

Hardware/PCB repo

AC-to-DC Converter PCB

An AC-to-DC converter with KiCad schematics and gerbers.

KiCadPCB

Hardware/PCB repo

Fire Detection System Jun 2024

A smoke-based fire alert system using an MQ-2 sensor.

MQ-2Arduino

IoT repo

Water Level Detector May 2024

A water level detector with overflow alerting.

ArduinoSensors

IoT repo

Rain Detector

An Arduino-based rain detector.

ArduinoSensors

IoT repo

Morse Caster Jan 2024

A text-to-Morse converter with LCD output.

ArduinoLCD

IoT repo

Digital Dice

An Arduino digital dice with a 7-segment display.

Arduino7-seg

IoT repo

Click Counter Up/Down

An Arduino up/down click counter.

Arduino

IoT repo

// 02 — overview

From hardware to custom Linux to on-device ML

A full-stack embedded engineer — silicon to UI.

I'm an Electronics & Communication Engineering graduate (RGUKT Srikakulam, 2026) who works across the entire embedded stack: hardware and PCBs in KiCad, bare-metal and RTOS firmware on ESP32 and STM32, a custom Yocto Linux distribution built from the recipe up, and ML and voice models running directly on-device. The interesting problems usually live at the seams between those layers — that's where I spend my time, and it's why I like owning a system end to end, from the device tree to the deploy flow. Right now that means contributing to eOS at Elipse; before that, an anti-collision safety system I built firmware for as an intern went into production at Tata Steel BlueScope — the projects above tell both stories in full.

// 03 — revision history

Where I've done the work

May 2026 – Present active

Embedded Systems Engineer · Elipse

Hyderabad, India

Contributing to eOS at Elipse — a custom Yocto-based Linux distribution for the Raspberry Pi 5 — owning the build-and-deploy pipeline, the Rust sensor-fusion framework, and the on-device voice subsystem.

Own the build-and-deploy flow end to end: Yocto recipes across the meta-eos layer with BitBake PR bumps, AUTOREV pinning, and IPK packaging, through the in-house eos-build CLI, WIC images, bmaptool flashing, and RAUC A/B verification.
Built the on-device voice subsystem in Rust: transfer-learned wake word (PyTorch → ONNX → tract), multi-mic best-source fusion across ESP32 satellites, Whisper STT, Piper TTS, and async barge-in.
Authored ESP32 satellite firmware (ESP-IDF v5.2): BLE provisioning with on-chip EC P-256 keygen and X.509 CSR exchange with the hub CA, full NVS lifecycle across OTA, and SNTP-synced audio streaming.

Full detail: eOS — FIG. 01 above

YoctoBitBakeRAUC OTARustD-BusMQTTSQLiteQt6/QMLESP-IDFONNX/tractWhisperPiper

Sep 2025 – Mar 2026 deployed

Embedded Systems Engineer Intern · Radiogeet

India

Developed an industrial Anti-Collision System for crane operations — deployed at Tata Steel BlueScope — using real-time UWB proximity detection and zone-based safety logic to prevent hazardous crane movements.

Shipped the Anti-Collision System to production at Tata Steel BlueScope: real-time UWB proximity sensing with zone-based safety logic driving industrial relays that halt unsafe crane motion.
Wrote ESP32-S3 dual-core firmware — one core for time-critical UWB ranging, the other for zone logic and the embedded web UI — linked over ESP-NOW and driving 8-channel Masibus relays via MODBUS RTU over RS485.
Interfaced STM32 with AHT10 and ADS1115 — timers, internal ADC/DAC, 2/4-wire RS485, LoRa long-range links, and Masibus DI/DO/AI/AO cards (STM32CubeIDE).

Full detail: FIG. 02 above

ESP32-S3FreeRTOS dual-coreUWBESP-NOWMODBUS RTU / RS485STM32LoRaIndustrial relays

Mar 2025 – Sep 2025

R&D Engineer · Ampnics

Remote

Worked on open-source hardware — designing and reviewing PCB schematics and layouts, and supporting rapid prototyping.

Designed and reviewed PCB schematics and layouts for open-source hardware.
Supported rapid prototyping through circuit testing, debugging, and iterative design.

KiCadPCB DesignSchematic CapturePrototypingOpen-Source Hardware

education

B.Tech, Electronics & Communication Engineering CGPA 8.3 / 10

RGUKT Srikakulam, Andhra Pradesh 2022 – 2026

Pre-University Course GPA 9.63 / 10

RGUKT Srikakulam, Andhra Pradesh 2020 – 2022

languages

English: Proficient
Telugu: Native
Hindi: Native

// 04 — specifications

The full embedded stack

Embedded Linux & OS

Building custom Linux distributions from the ground up with Yocto.

Yocto ProjectBitBakeOpenEmbeddedkasmeta-layers.bb/.bbappend recipesIPK packagingRAUC A/B OTACustom distro buildCross-compilationBSPDevice tree

Linux Internals

The userspace plumbing that ties a running system together.

systemdD-BusjournaldSQLiteMosquitto MQTT (TLS, ACL)

Firmware & RTOS

Bare-metal and RTOS firmware on ESP32 and STM32 silicon.

ESP-IDF v5.xFreeRTOS dual-coreSTM32 HAL/LLBare-metalInterrupt/pollingBLE (NimBLE)NVS lifecycleOTA

On-Device ML & Voice

Wake-word, speech, and sensor inference running entirely on the edge.

PyTorchONNXtract (Rust)Transfer learningKWSVADMel-spectrogramWhisper STTPiper TTSMulti-mic fusionBarge-in

Languages

Systems and application languages I write production code in.

CEmbedded C/C++Rust (async/Tokio)PythonMATLAB

Sensors & Peripherals

Radar, air-quality, and industrial I/O I interface and calibrate.

HLK-C4001 mmWave radarPIR motionPM/VOC/CO₂ air-qualityAHT10ADS1115 ADCUWB modulesMasibus DI/DO/AI/AOIndustrial relays

PCB & Hardware

From schematic capture to flashed boards and bring-up.

KiCadSchematic captureLayoutPower-supply designRaspberry Pi 5ESP32 / ESP32-S3STM32

UI & Tooling

The build flow, IDEs, and front-end that ship the work.

Qt6/QMLGit / GitHubSTM32CubeIDEESP-IDFkasBitBake

// communication protocols

UART SPI I²C CAN RS485 (MODBUS RTU) MQTT D-Bus BLE Wi-Fi ESP-NOW LoRa UWB

// 05 — compliance & test

Certifications

NPTEL · 2025 completed

Embedded Sensing, Actuation and Interfacing Systems

85%

view certificate

NPTEL · 2025 completed

Electronic Systems Design — Circuits & PCB Design with CAD

88%

view certificate

// 06 — contact & ordering info

// available for embedded roles

Let's build something close to the metal

Email: royramu694429@gmail.com
Phone: +91 94936 52315
GitHub: github.com/ramuroy (opens in new tab)
LinkedIn: Ramu Roy (opens in new tab)
Location: Hyderabad, India

OPEN MAILTO DOWNLOAD CV

Ramu RoyRamu Roy.

eOS

Industrial Anti-Collision System

On-Device Voice Subsystem

// selected on github

Embedded Systems Engineer · Elipse

Embedded Systems Engineer Intern · Radiogeet

R&D Engineer · Ampnics

Embedded Linux & OS

Linux Internals

Firmware & RTOS

On-Device ML & Voice

Languages

Sensors & Peripherals

PCB & Hardware

UI & Tooling

Embedded Sensing, Actuation and Interfacing Systems

Electronic Systems Design — Circuits & PCB Design with CAD

Let's build something close to the metal