Hire the Best Bluetooth Freelancers
in China

Senior Software Architect specializing in secure systems and IoT Sec solutions with 15+ years of experience. I architect and deliver end-to-end nfc solutions, from embedded firmware to cloud-based backend systems. 🎯 CORE EXPERTISE IOT Systems - NFC Solutions: Reader/Writer, HCE, Digital Wallets (Android/iOS) - Smart Cards: JavaCard, MIFARE, DESFire, NTAG,Global Platform,GP,JCOP,Secure Element - Security: PKI, FIDO, Secure Element,HSM, PCI-DSS Compliance - RFID Systems: Asset Tracking, Access Control - EMV Payment: L1/L2/L3 Kernel Development & Certification - Microcontrollers: ESP32, STM32 (WiFi/BLE, RTOS) - Firmware: Secure Bootloader, OTA Updates, Real-time Systems - Industrial Applications: POS Terminals, Vending Machines, Access Control - IoT Architecture: Sensor Integration, Remote Management Full-Stack Development - Backend: Node.js, REST APIs, Database Design (SQL/NoSQL) - Cloud Services: Firebase, AWS/Azure/GCP Deployment - Mobile: Android (NFC APIs), iOS (CoreNFC), React Native - Desktop: Qt, .NET, Cross-platform Applications - Languages: C/C++, JavaScript/TypeScript, Java, C# 💼 SIGNATURE PROJECTS ✅ ESP32 IoT Systems - Created NFC-enabled payment solution with cloud integration - Built secure firmware with OTA update capabilities - Integrated Firebase for real-time data synchronization ✅ Cross-Platform Digital Wallet - Developed mobile wallet supporting EMV contactless payments - Implemented HCE and Secure Element integration - Built Node.js backend with Firebase authentication ✅ Enterprise RFID Solutions - Designed asset tracking systems for industrial clients - Implemented access control with NFC/RFID readers - Deployed cloud-based management platform ✅ EMV Payment Terminal Solutions - Developed EMV L2 & L3 kernel for contact/contactless terminals - Achieved EMVCo certification for payment applications - Implemented secure key management and transaction processing 🔧 TECHNICAL STACK Hardware: ESP32, STM32, NFC Readers, RFID Systems Backend: Node.js, Express, Firebase, REST APIs Database: MongoDB, PostgreSQL, MySQL, Firestore Cloud: Firebase, AWS, Azure, Docker deployment Mobile: Android, iOS, React Native Desktop: Qt, .NET, Windows/Linux Security: PKI, FIDO, PCI-DSS, Secure Boot 📋 CERTIFICATIONS & STANDARDS EMVCo, PCI-DSS, PBOC, Global Platform, ISO 14443 I deliver production-ready solutions with clean code, comprehensive documentation, and ongoing support. Available for both fixed-price projects and long-term contracts.

I am a professional embedded software engineer with more than 10 years of experience. My current areas of expertise are IoT Applications & Embedded Systems Design, including embedded hardware/software. My Skills: - Know about MCU: Nordic, Silicon Labs, AVR, PIC,ESP32, etc. - Have experience in programming languages such as C/C++, - Solid knowledge of standard interfaces such as I2C, SPI, UART, and CAN. - Have experience using debugging tools such as Segger Jlink, CAN bus analyzer, Logic analyzer,RF analyzer. - IoT devices with wireless connectivity such as LTE, CAT-M1, NB-IoT, BLE, WIFI, NFC - Good experience in Battery Management Systems based on BQ products from TI. - Have experience using Alitium designer,Kicad - Know about medical Regulations and Directives such as EN 300 328,RoHS & REACH，EN 62368-1，EN 55032, EN 55035 etc. The development platform : - Keil .stm32cube, Micochip studio - On semiconductor IDE, Simplicity studio, - esp32-idf, Arduino - nrf connect sdk What I can do for you: (1 ) Electronic components selection,Schematic , PCBA design, output production files (2) Help you to review schematic , pcb files, and test hardware (3) quickly assist in making pcba samples, functional verification and abnormal problem analysis (4) Embedded software development from 0 to 1. (5) Help you to add new function or module to your embedded software system (6) Help you to review code ,test , fix bug in softeware (7) Based on the prototype of your needs, convert it into an actual embedded system design My advantage: （1） The processing and manufacturing efficiency in China is very high, and the cost of components is very low. If you want to do circuit modification and verification, I can use China's JLC and Taobao to quickly make PCBA. （2）I'm a full-stack developer capable of tackling both software and hardware challenges. This allows me to consider software design feasibility and convenience from a hardware design perspective, and vice versa.

I specialize in building Android Kiosk Mode (Lock Task Mode) applications for enterprise and dedicated devices. My experience includes developing robust Android apps that interact with BLE (Bluetooth Low Energy) devices, handling real-world hardware constraints, and ensuring reliability in production environments. I also build custom Android launchers, including minimal and productivity-focused designs similar to Niagara-style experiences. In addition to my Android expertise, I am expanding into cross-platform development using Flutter, with a focus on integrating native Android features and supporting iOS deployments. I have hands-on experience working with mobile subscription systems, including Google Play Billing and App Store in-app purchases. I can help implement subscription flows, purchase validation, and lifecycle handling. I am comfortable dealing with complex Gradle configurations, build issues, and debugging challenging edge cases. If you are looking for a developer who understands both system-level Android and modern mobile app requirements (including subscriptions and cross-platform solutions), I’d be happy to help.

I help companies debug, stabilize, and ship embedded products on STM32, ESP32, nRF52, EFR32, NXP KL17, JieLi, HDSC, and other ARM / RISC-V platforms. Typical problems I solve: • STM32 hard faults, crashes, boot issues • Custom board bring-up and peripheral integration • BLE / LoRa / MQTT connectivity issues • RS485 / Modbus communication instability • Low-power optimization for battery-operated devices • OTA reliability issues • Porting firmware to new boards, MCUs, or RTOS platforms • Turning prototypes into production-ready firmware I have 15+ years of embedded development experience across industrial communication systems, low-power IoT devices, wireless products, and mass-production consumer electronics. My background includes product lines with more than 10M devices shipped. Core platforms and technologies: • STM32 / ESP32 / nRF52 / EFR32/ NXP KL17 / JieLi • FreeRTOS / Zephyr / Arduino / PlatformIO • BLE / LoRa / NB-IoT / 4G / Cat.1 • RS485 / Modbus / UART / SPI / I2C • AWS IoT / MQTT / OTA • Battery-powered and ultra-low-power systems Selected experience: • STM32H7 controller platform with dual-core architecture, LVGL UI, RS485 communication, and ESP32-S3 connectivity co-processor • Ultra-low-power fault indicator for utility networks with multi-year battery life and LoRa communication • BLE thermal printer platform focused on wireless stability, motor control, print control, and production reliability Why clients work with me: • Strong debugging and root-cause analysis • Real production and manufacturing support experience • System-level architecture thinking • Clear communication and practical decisions • Reliable long-term collaboration Available for: • Firmware debugging and stabilization • Custom board bring-up • New feature development • RTOS-based firmware architecture • Wireless and industrial communication projects • Long-term embedded support Based in China (UTC+8), with flexible overlap for US / EU / AU teams. Typical response time: within 4 hours. Currently available for new debugging, bring-up, and embedded firmware support projects.

I’m Simon, Heading the IoT Systems architecture at Maxlinktek (US), supported with my own high-performance R&D team in China. Skills: ● Systems/Product architecture. ● PCBA design (Altium/KiCad) ● Linux Kernel/APP development(C/C++) ● STM8/STM32/ESP32/CH59x BLE/Other MCUs development(C/C++) ● PHP Laravel + Swoole(server backend) ● VUE UI(HTML5/Javascript) ● Android/iOS APP development(Flutter/Electron) ● DFM (Design for Manufacturing): Optimization for high-yield assembly and die-casting to minimize defects. ● Mass Production (MP) Management: Experienced in overseeing the lifecycle from EVT/DVT/PVT to full-scale production. ● BOM Optimization: Strategic sourcing and component selection for supply chain resilience and cost-efficiency. ● Regulatory Compliance: Pre-scan and verification for international standards (UL, CE, FCC, IP67/68). I bridge the gap between US-standard strategic leadership and direct Shenzhen factory-floor execution.With 15+ years in Linux development & maintenance and 8+ years in professional PCBA engineering, I specialize in building production-ready IoT ecosystems — from the first circuit trace to global mass production. This setup allows me to provide US-standard communication and project management, combined with unmatched cost-efficiency and R&D speed through my dedicated team in China. FROM PROTOTYPE TO MASS PRODUCTION 🚀 WE BUILD SCALABLE IOT ECOSYSTEMS — NOT JUST DEMOS. Most IoT projects fail after the prototype stage. We bridge the gap between a "bench-top demo" and a global product launch.. --- 💡 WHY PARTNER WITH US? ●●30%-75% Hardware Cost Reduction: We replace bloated Android systems with high-performance Native ARM Linux. This achieves the same fluid UI/UX with significantly lower hardware requirements, without sacrificing system stability or response speed. ●●20-40% BOM Optimization: Based on 8+ years of supply chain expertise, we proactively suggest reliable chip alternatives. We optimize your profit margins by selecting components that offer equivalent or superior performance at a more competitive price point. ●●Zero-Gap Delivery: We perform deep on-site debugging in China; you receive fully functional, debugged units—not bare boards. --- ⚙️ WHAT WE DO ? (OUR "PRODUCTION-FIRST" CAPABILITIES) ► HARDWARE ACCELERATION (DFM TO DELIVERY): ●●High-density PCBA design (Altium/KiCad) integrated with China’s elite supply chain for ultra-fast SMT and prototyping.We eliminate the costly "ship-debug-fail" cycle. ●●Precision Design: Layouts optimized for Design for Manufacturing (DFM) to ensure high yields. ●●Supply Chain Resilience: Multi-source component selection to survive global shortages. ► SOFTWARE & FIRMWARE INFRASTRUCTURE: We develop the critical "brain" that turns hardware into an enterprise-grade service. ●●Embedded Mastery: Native ARM Linux & Deep MCU (ESP32/STM32) optimization. ●●High-Concurrency Backend: PHP/Swoole & Laravel Octane managing 10,000+ live devices (MQTT/WebSockets). ●●Modern Interfaces: High-performance Web (VUE) and Cross-platform Mobile Apps (Android/iOS). ●●15+ Years Linux Maintenance: Expert server hardening and high-density automation (KVM/LXC/Docker). ●●Strategic OTA: Industrial-strength infrastructure to ensure security and long-term product evolution. ► AUTOMATED MASS-PRODUCTION PROVISIONING: We eliminate error-prone "manual flashing" with custom One-Device-One-ID tools, real-time cloud sync, and integrated packaging traceability. --- 📦 PROVEN TRACK RECORD Due to strict NDA obligations with enterprise clients, only a selected portion of my track record is showcased below. I maintain a high standard of intellectual property protection for all partners." ●●LG DUOBO Coffee Machine: End-to-end integration (PCBA, Firmware, App). ●●Nscreen32: World’s first LVGL-certified development board. ●●Ntablet: Successful open-source hardware tablet. --- 🤝 WHO WE WORK WITH 1. We seek serious IoT startups and product teams who view their products as long-term business ventures. We build for mass production from day one—from the first circuit trace to the global App Store release. 2. We partner with startups and product teams who want to build **real products — not just prototypes**. If you're planning: - An IoT product launch - Scaling from prototype to production - Or fixing a system that doesn’t scale 👉 We can help. --- 👉 Send an invite with a short description of your project and I’ll suggest a simple system architecture for you (no obligation).

I am Jennis Mike, an Embedded Systems and Product Developer focused on building real-world hardware and software systems that can move from prototype to production. My work combines embedded firmware, PCB design, IoT systems, and mobile/web integration. I work primarily with STM32 and ESP32 microcontrollers using workflows such as ESP-IDF, FreeRTOS, UART/SPI/I2C communication, motor control, and wireless systems. I also design custom PCBs using EasyEDA and prepare boards for manufacturing with JLCPCB. My projects include robotics systems, balancing robots, connected devices, and mobile applications. On the software side, I develop Flutter mobile applications, backend-connected platforms, and React-based web applications using Supabase and modern development workflows. Skills and experience include: • STM32 and ESP32 Development (ESP-IDF) • FreeRTOS • Embedded C/C++ • PCB Design & Schematic Design • EasyEDA & JLCPCB Manufacturing Preparation • IoT Systems • Flutter Mobile App Development • React-based Web Applications & Supabase Integration I enjoy solving engineering problems and helping turn ideas into functional prototypes and products.