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Sidlaghatta, India

IoT & Embedded Systems Engineer ESP32, Raspberry Pi, Sensors

New to Contra

IoT & Embedded Systems Engineer ESP32, Raspberry Pi, Sensors

Cover image for Title: FlowSense Pro -

Title: FlowSense Pro - Industrial Flow & Chemical Dosing SCADA Gateway with OPC-UA & BLE Problem: Municipal wastewater treatment plants, breweries, and chemical processing facilities rely on analog 4–20 mA pressure/flow transmitters and mechanical pulse flow meters that lack native network connectivity. Modernizing these field instruments into SCADA platforms historically required dedicated automation racks and programmable logic controllers, inflating per-station deployment costs. Additionally, field technicians in wet, hazardous environments struggle with device commissioning and routine calibration because older systems require physical laptops, terminal blocks, and USB-to-serial cables. Traditional field gateways also lack secure, fail-safe remote firmware updates (OTA), risking operational downtime during software maintenance. Solution: Built a ruggedized, DIN-rail mounted smart gateway around the ESP32-S3 (Xtensa dual-core 240MHz) utilizing ESP-IDF v5.x: High-Precision Dual Measurement: Combines a 16-bit ADS1115 ADC and a 0.1% precision 100 Ω shunt to read 4–20 mA current loops with ±0.5% calibrated accuracy, alongside a hardware pulse counter (PCNT) interrupt engine reading turbine flow meters up to 500 L/min. Direct SCADA & OPC-UA Integration: Compiles the open-source open62541 OPC-UA stack directly into ESP-IDF, enabling the gateway to communicate natively with SCADA servers and industrial HMIs over TCP/IP without intermediate PLC hardware. Cable-Free BLE Commissioning: Implements a custom BLE 5.0 GATT profile that allows field operators to calibrate sensor K-factors, set alarm thresholds, and configure local Wi-Fi credentials via an iOS/Android mobile companion app in seconds. Zero-Power Display & Fail-Safe Actuation: Integrates an ultra-low-power 2.9" SPI E-Paper display that maintains critical process readouts even during brownouts, alongside four opto-isolated 24V/3.5A power MOSFET outputs driving dosing pumps and emergency shutoff valves in <10 ms. Enterprise Security & Robust OTA: Employs mutual-TLS (mTLS) certificate-based authentication with AWS IoT Core and dual-partition HTTPS OTA with automated bootloader rollback upon boot failure.

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Cover image for Title: Smart Assistive Gesture Glove

Title: Smart Assistive Gesture Glove and Caretaker Alert System 1. Problem statement: Speech-impaired, partially paralyzed, or bedridden patients often struggle to communicate basic necessities (food, water, washroom, physical discomfort) or call for immediate emergency help without a caregiver continuously in the room. Standard push-button call systems lack expressive nuance, while cloud-reliant smart devices fail completely whenever local Wi-Fi or internet connectivity drops, posing a critical safety hazard during medical emergencies. 2. Solution and Technical Implementation: Gesture-to-Intent Recognition: The patient wears a wearable glove equipped with four flex sensors. Using trimmed-mean signal sampling and Exponential Moving Average (EMA) filtering, the system filters out muscle tremors and maps individual finger flexes to primary needs (Food, Washroom, Water, Discomfort), with a chorded fist gesture reserved for an instant Emergency SOS. Zero-Downtime Local Transmission: Communication between the glove and the caregiver base station uses peer-to-peer ESP-NOW radio protocol. This operates completely independent of routers or internet access, featuring an auto-channel hopping algorithm on the glove to maintain the radio link even if radio channels shift. Multi-Modal Feedback & Cloud Alerts: The receiver base station converts incoming packets into immediate spoken voice alerts via a DFPlayer Mini MP3 module, visually displays the request on an SSD1306 OLED, and sounds an active buzzer during SOS events. Non-Blocking Remote Gateway: An asynchronous FreeRTOS background task pinned to Core 0 relays every command and glove-disconnection warning directly to the caregiver’s smartphone via a Telegram Bot, ensuring family members stay informed even when away from the base station without delaying real-time local alarms.

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Cover image for Title: Industrial IoT Environmental Monitor,

Title: Industrial IoT Environmental Monitor, OLED HUD & Actuator Node Description: An autonomous edge-computing IIoT monitoring and safety node built using an ESP32 microcontroller. The system tracks real-time environmental metrics and executes local automation logic with zero cloud latency. Key features: 1. Multi-Sensor Telemetry: Integrates a BME280 sensor for ambient temperature, humidity, and barometric pressure alongside an MQ-135 sensor for real-time air quality and gas detection. 2. Local OLED HUD Dashboard: Features an SSD1306 OLED display to provide operators with crystal-clear, on-site visual diagnostics and live system status updates. 3. Autonomous Edge Actuation: Automatically triggers an opto-isolated relay (M281) and piezo buzzer to drive ventilation fans and warning alarms when safety thresholds are breached. 4. Optimized Firmware: Powered by clean C/Arduino code utilizing hardware I2C communication, analog data mapping, and robust Active-LOW relay control logic.

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Cover image for Title: SmartMill Guardian - CNC

Title: SmartMill Guardian - CNC Machine Predictive Health & Vibration Diagnostics Edge System Problem statement: High-precision CNC milling centers and industrial machining tools frequently suffer from sudden spindle bearing degradation and thermal runaway. A single unplanned spindle seizure costs manufacturing facilities upwards of $40,000 per incident in damaged workpieces, emergency tooling, and shop-floor downtime. Traditional plant maintenance relies on manual spot checks every 4 to 8 hours or cloud-only IoT gateways that suffer from 2–5 second network latencies—far too slow to trigger an emergency feed-hold before catastrophic mechanical failure. Furthermore, retrofitting older factory machinery with proprietary PLC hardware (e.g., Siemens S7 racks) is prohibitively expensive and requires disruptive rewiring. Solution: Designed and deployed a deterministic edge monitoring unit powered by a Raspberry Pi 4B running bare-metal FreeRTOS and Embedded C (C99): High-Rate Vibration FFT: Interfaces with an ADXL345 3-axis MEMS accelerometer via hardware SPI at 1 kHz ODR. An on-chip CMSIS-DSP Fast Fourier Transform (FFT) paired with a lightweight µTensor INT8 model identifies bearing defect frequencies (BPFO/BPFI harmonics) with 94% accuracy. Thermal Profiling & PLC Bridging: Continuously monitors bearing temperatures using an MLX90614 infrared sensor over I²C while polling spindle speed, drive current, and status words from existing Siemens S7-1200 PLCs over RS-485 Modbus RTU. Deterministic Emergency Interlock: Features a 4-channel opto-isolated relay interface capable of triggering a CNC machine feed-hold or spindle stop in <5 ms upon anomaly detection—eliminating cloud latency. Cloud & SCADA Telemetry: Securely streams time-series vibration metrics and alerts via TLS 1.3 MQTT to AWS IoT Core, populating live shop-floor InfluxDB and Grafana dashboards for condition-based maintenance scheduling.

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Adeagbo AbdulJeleel

Designing PCBs, electronics, embedded and product design

New to Contra

Designing PCBs, electronics, embedded and product design

Cover image for IoT-Based USD to IDR Exchange

IoT-Based USD to IDR Exchange Rate Display Using Bank BCA Exchange Rates Real-Time Bank BCA USD/IDR Exchange Rate Monitor using ESP32 and OLED Display with live internet updates. Features: • Real-time USD/IDR exchange rate display • ESP32 WiFi connectivity • OLED SSD1306 interface • Automatic online data refresh • Lightweight and low-power system • Compact embedded monitoring device #ESP32 📡 | #IoT 🚀 | #EmbeddedSystems 💻 | #Arduino ⚙️ | #Programming 📚

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Cover image for Raspberry Pi CM5 IO Board

Raspberry Pi CM5 IO Board with USB 2.0 OTG The official Raspberry Pi Compute Module 5 IO board doesn’t include the USB 2.0 path switch IC, which was in its elder brother CM4 IO board. Also, it uses CM5’s own CC control pins for USB Type C port. To make my design compatible with both CM4 and CM5, I integrated an USB 2.0 switch IC in the similar way, but with a little bit different configuration. The board need to have 2 x USB 2.0 ports. So I needed to add an USB 2.0 hub IC and an USB path switch chip, similar to the official Raspberry Pi CM4 IO board. But I needed to modify it to use an USB Type-C port and use CC control pins of CM5. The elder CM4 series modules didn’t have CC control pins. Thus, I also added DNP resistors, where I can solder 5.1K resistors for using CM4 on this board. The official Raspberry CM4 IO board used VBUS to automatically switch the OTG config via USB_OTG_ID pin. But on my design, +5V line may be supplied from external power source. It means I should use 5A rated ideal diode. But the requirements was only using USB 2.0 as normal Host, instead of standard USB OTG compatible port. As we anyway need BOOT button to set the compute module into flashing mode, I decided to use a DPDT slide switch instead of tactile boot button. In this way, I could manage setting BOOT and OTG_ID flags using a single switch sliding.

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Cover image for Arduino Nano-Based PCB Design
I designed

Arduino Nano-Based PCB Design I designed a custom PCB built around the Arduino Nano, creating a compact hardware platform for integrating the microcontroller with supporting electronic components and external peripherals. The design involved organizing the Arduino Nano interface, power connections, input/output lines, and supporting circuitry into a clean and practical PCB layout. I focused on efficient component placement, clear signal routing, reliable power distribution, and maintaining a layout that is easy to assemble and integrate into a larger embedded system. This project strengthened my experience in Arduino-based hardware development, PCB layout, embedded electronics, component integration, and microcontroller interfacing.

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Cover image for Raspberry Pi Zero Relay Board
I

Raspberry Pi Zero Relay Board I designed a custom Raspberry Pi Zero relay control board that combines a Raspberry Pi Zero development platform with multiple relay outputs for controlling external electrical loads. The objective of the project was to allow the Raspberry Pi Zero to electronically control the relays, providing a practical interface between the low-voltage digital signals from the Pi and connected external devices. My work involved developing the PCB layout around the Raspberry Pi Zero, organizing the relay circuitry, and carefully routing the control and power connections. Particular attention was given to component placement, signal routing, power distribution, isolation between the control circuitry and relay sections, and maintaining a clean, reliable board layout. The project provided valuable experience in Raspberry Pi hardware integration, relay control, PCB design, digital interfaces, and hardware prototyping, while demonstrating how a compact embedded platform can be integrated with a dedicated control board for real-world automation applications.

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proSan Francisco, USA

AI Campaign Assets + Agents for DTC Growth

$100k+: Earned

21x: Hired

5.0: Rating

301: Followers

Top

Partner

+1

AI Campaign Assets + Agents for DTC Growth

Cover image for Skye 0.0 - Holographic AI Assistant

Skye 0.0 - Holographic AI Assistant

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Cover image for Bliss Point: Engineering Craving with AI

Bliss Point: Engineering Craving with AI

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Cover image for Cinematic Storytelling for Liquor Brands

Cinematic Storytelling for Liquor Brands

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Cover image for Recess Spec Product Photography Campaign

Recess Spec Product Photography Campaign

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Brand designer & strategist

2x: Hired

5.0: Rating

11: Followers

Brand designer & strategist

Cover image for Between 2018 and 2019, I

Between 2018 and 2019, I built The End of Emotional Privacy (https://martinasoles.framer.website/work/the-end-of-emotional-privacy-a-speculative-design-thesis-on-emotional-surveillance), my Master's thesis at IAAC exploring how empathy could be felt physically. I designed a bodysuit that translates emotions into real-time heat, using infrared sensors to read body temperature and heat pads built from conductive thread, so happiness, sadness, anxiety, and fear could be physically felt on the wearer's back. I paired it with a live p5.js visualization so people could see the detected emotional state as well as feel it. It was selected for Global Grad Show in Dubai, later exhibited at the Design Museum of Barcelona, and covered by El País and TV3.

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Cover image for For Braby's, my baby-first concept

For Braby's, my baby-first concept restaurant, I'm exploring the idea of a BLW (baby-led weaning) menu. Not sure how realistic this could be in a real restaurant because of how chaotic it could get (I'm currently exploring this at home with my own baby), but I had fun designing the menu! It works as a seasonal checklist of foods your baby should be introduced to, and it gets more interesting as your baby grows. As for the adults accompanying the babies, they can just get the +12 months tapas available on the menu, so babies and family get to eat the same! Except that we might want to add salt and some condiments to make it more yummy. Again, this is just a concept, but what do you think?

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Cover image for Currently working on a baby

Currently working on a baby first restaurant. This is the mood and a first draft of the logo. What do you think?

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Sunsies Studio brand design and creation

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Harshit Bhandari

Game Developer | Prototyping, Mobile, AI & Multiplayer

Game Developer | Prototyping, Mobile, AI & Multiplayer

Cover image for Creature Lab Arcade Game Development

Creature Lab Arcade Game Development

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Cover image for Built an AR Furniture Visualization

Built an AR Furniture Visualization POC. Users can: • Preview furniture in 3D • Place it in their real environment • Move, rotate, and scale it naturally • Visualize how it fits in their space We also explored a GLB-based asset pipeline to simplify 3D model and texture management. Here's a quick demo. Building something similar? Let's talk.

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Cover image for One conversation with a client

One conversation with a client reminded me that innovation isn't always about creating something from scratch. Sometimes, it's about taking a good product that's struggling to deliver the right experience - and helping it reach its full potential. Recently, a team approached us after developing an educational multiplayer game designed to create awareness around reducing carbon emissions. The concept, gameplay, and design were already in place. They weren't looking for a redesign. They wanted players to enjoy the experience as much as they believed in the idea. The Challenges We Identified - After reviewing the application, a few key issues stood out: - Frequent lag and game freezes were disrupting gameplay. - Animations running at 30 FPS made the experience feel less responsive. - Graphics were limited to 720p, affecting visual quality. - Players found parts of the interface confusing, making the game less intuitive. - Hindi graphics weren't rendering correctly, limiting accessibility. - Since the game required five participants, sessions often couldn't begin if enough players weren't available. None of these problems affected the concept of the game-but they had a significant impact on player engagement. How We Solved Them Instead of changing the product itself, we focused on improving how users experienced it. Our team: - Increased animation performance from 30 FPS to 60 FPS for smoother gameplay. - Upgraded the graphics from 720p to 1080p to create a sharper and more immersive experience. - Simplified the interface so players could understand the game more naturally. - Implemented Chanakya to render Hindi graphics accurately. - Introduced AI-powered players, allowing games to continue even when all five participants weren't available. The Outcome What changed wasn't the idea - it was the experience. The gameplay became smoother, the visuals became more engaging, multilingual support made the product more inclusive, and AI ensured players could enjoy uninterrupted sessions without waiting for a full group. For me, this project reinforced an important lesson: users rarely stop using a product because the idea is weak. More often, they leave because small technical friction gets in the way of a great experience. As technology partners, that's where we can make the biggest difference - not by replacing good ideas, but by helping them perform the way they were always meant to. I'm curious to know your perspective. If you had to prioritize just one while improving a digital product, what would it be? A) Performance B) User Experience C) Accessibility D) AI-powered capabilities Drop your answer in the comments - I’d love to know what you think.

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Cover image for Balance Master - Monogame based arcade game

Balance Master - Monogame based arcade game

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Consuelo Burotto

Barcelona, Spain

Im a Senior Product Designer with over 8 years of experience

New to Contra

Im a Senior Product Designer with over 8 years of experience

Cover image for product design · ux strategy
polucio
An

product design · ux strategy polucio An environmental information system for classrooms Air quality in classrooms tends to go unnoticed. CO₂ buildup happens gradually and silently, affecting the wellbeing and focus of students and teachers with no clear signal to act on. Polucio was conceived as an accessible environmental information system that turns complex data into a simple visual signal, letting anyone in the room understand when it's time to ventilate the space without relying on technical data or external apps.

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Cover image for Create Landing page for DIOR

Create Landing page for DIOR

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Cover image for Talent Capital — AI-Native Candidate Platform

Talent Capital — AI-Native Candidate Platform

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Cover image for I'd like to share my

I'd like to share my portfolio. It's still a work in progress, but it already includes several of the projects I've been working on. https://cebe-studio.vercel.app/

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Brand identity, web design & dev. Fast, precise, opinionated

Brand identity, web design & dev. Fast, precise, opinionated

Cover image for GreenHale | Scent Collection & Sharing System

GreenHale | Scent Collection & Sharing System

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Cover image for A speculative manual for a

A speculative manual for a yarn-based programming language, where crochet stitches form a visual syntax from individual loops to modular granny squares as executable units. Inspired by the Jacquard Loom's binary punch-card logic, the project asks whether weaving patterns can function as a form of language. Unlike logic-driven code, this soft computer operates closer to pictographs: concrete, tactile, and craft-based.

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Cover image for CARE MART

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Cover image for This project is inspired by

This project is inspired by the immortal jellyfish, a creature that can switch between two life stages, polyp and medusa. When it gets scared, it spits out polyps as a way to protect itself. The jellyfish sits on your head like a companion. A friend that shows what's really going on inside you. Kind of like the characters in Pixar's Inside Out, it makes your inner feelings visible. The medusa is the calm outer self, and the polyp is what comes out when you feel overwhelmed or frightened, the fragile, honest thoughts you normally keep hidden. The headpiece reacts to people nearby through a distance sensor. When someone gets too close, the jellyfish gets startled and its movement changes, just like how we tense up or pull back in social situations. It's a companion that doesn't hide your emotions.

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Abdulbasit Ogundiran

Cybersecurity Analyst | Cloud Security & IT Operations

New to Contra

Cybersecurity Analyst | Cloud Security & IT Operations

Cover image for This is a project that

This is a project that I titled Low-cost AI Power theft detection that detects electricity theft, bypass of electricity, high electricity usage, with the help of TinyML integrated and trained into the esp32 and alert with the help of the buzzer and shows in a well polished web dashboard, sensor used would be communicated after the project as been finally built and ready for implementation.

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Cover image for This is a project I

This is a project I titled: Development of High Blood Pressure (HBP) Prediction and Monitoring System Using CNN-BiLSTM and Fuzzy Logic in Real Time Still undergoing development: 1. The Flask backend is operational with an integrated CNN-BiLSTM prediction pipeline and a fuzzy logic module for health risk assessment, along with REST API endpoints for communication. 2. A Flutter mobile application has been developed, featuring a dashboard that displays various health metrics and successfully communicates with the backend. ‎3. Hardware development includes the successful configuration of the ESP32 microcontroller, integration of an OLED display, and testing of the MAX30102 PPG sensor for real-time waveform acquisition. 4. AI integration involves transmitting real PPG data from the MAX30102 sensor to the Flask backend, where the CNN-BiLSTM model generates blood pressure predictions, which are then returned to the ESP32 and backend. ‎5. The complete communication pipeline from sensor to monitoring dashboard has been established, confirming successful real-time signal processing for blood pressure prediction. ‎6. Ongoing work focuses on sensor stabilization, hardware integration, synchronization of live updates, alert mechanisms, power management, and final system packaging. 7. The core real-time HBP prediction system using CNN-BiLSTM is implemented and tested, with the project now in the optimization stage before final deployment. Willing to hear suggestions and getting more gigs to work with and solving of problems

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Cover image for My lab environment, and this

My lab environment, and this is a project giving to me by a client to test my ethical hacking skill cracking an encrypted .rar file open and seeing the content inside, I was authorised and I confirmed it was his before I performed my attacks. And I successfully hacked into it. Not to be disclosed cause of what it contains and for privacy but this was when I was working on the project. So am opened to share my expertise and solving problems in whatever you bring to my table. Lekk's Forge got you covered.

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Cover image for A fully functional health website

A fully functional health website for a project given to me to work on by a client but still on development stage. It shows a lot of detailed information and a graph to express the blood pressure trends, with the help of AI prediction using various models to make this possible. Will deliver soon and talk more about it when done.

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