Smart Lock Hardware & Firmware Development Using nRF52840

Client Location: Europe

Industry: Smart Home & Commercial Access Control

Technology Partner: Adequate Infosoft

Core Platform: Nordic Semiconductor nRF Series

One of our European customers is a rapidly expanding smart security firm that specializes in developing cutting-edge access control solutions for residential apartments, office buildings, co-working spaces, and short-term rental properties such as Airbnb’s.

Their goal was to replace traditional mechanical locks and fragmented access systems with a single, intelligent, secure, and connected smart lock platform.

They contacted Adequate to provide an entire end-to-end solution for the design and implementation of the BLE smart locking system including electronic components, firmware, back-end development on the cloud, mobile application development, and manufacturing of the physical product.

The client wanted an integrated smart-lock system that allows for different ways to authenticate access. The device must also achieve a high level of security, be low powered, and be scalable to accommodate future growth and changes in technology.

The key features needed are:

• Mobile unlocking through BLE
• Authentication through fingerprint;
• Access via RFID card/tag
• Access via secure keypad PIN
• Capability to be used offline
• User & access management through cloud computing
• Mobile applications (iOS & Android)
• Long battery life and Hardware designed and built fully ready to manufacture.

The solution developed by Adequate Infosoft is an integrated multi-access smart lock system, consisting of hardware, embedded firmware, cloud and applications powered by Nordic Semiconductor Controllers.

Access Methods Implemented

• BLE Mobile Unlock (Smartphone App)
• Capacitive Fingerprint Sensor
• RFID (MIFARE / NFC-compatible cards)
• Touch Keypad (PIN-based access)
• Admin & Temporary Access Codes

The management of these various access methods is controlled through a single firmware and cloud platform for easy administration.

Nordic Products Used

• nRF52840 – Primary BLE SoC
• Bluetooth 5.0 / 5.2 (BLE Long Range)
• High-performance ARM Cortex-M4F
• Secure boot and hardware cryptography
• nRF52 Series (nRF52832) – Secondary variants for cost-optimized models
• Nordic SoftDevice S140 – BLE protocol stack

Hardware Parts

• Custom made 4-layer PCB
• Low Power Motor Driver for Locking
• Capacitive Fingerprint Module
• RFID Reader Module
• Touch Sensitive Keypad Interface
• Hall Sensors (Lock Position Detection)
• Battery Management and Power Supply Control
• Secured Debug and OTA Interfaces

We optimized the hardware for low power consumption, signal integrity and mechanical durability to meet the environmental and safety requirements of Europe.

Firmware Architecture

• Nordic nRF5 SDK and the Zephyr Real-Time Operating System for more advanced versions
• Modular design methodology
• State machine driven by events (i.e., will react to events)
• Secure bootloader with OTA support

Core Features of the Firmware

• BLE GATT services for operating the lock
• Secure pairing and establishing trus
• Encrypted processing of commands
• Method for determining access rights using multi-mode validation
• Capability to control motors and process feedback from motors
• Power optimization, this includes running in deep sleep, and waking on an event
• Validation of credentials in offline mode
• Logic to ensure a failure-safe condition exists while locking/unlocking

Security Implementation

• AES-128 encryption
• Secure storage of keys
• Rolling tokens for all BLE commands
• Protection against replay attacks
• Use of OTA for secure firmware updates

Adequate Infosoft built a scalable cloud backend to manage devices and users across thousands of locks.

Backend Tech Stack

• AWS Cloud Infrastructure
• REST & MQTT-based device APIs
• Secure device authentication
• Role-based access control (RBAC)
• Real-time access logs and audit trails
• Time-based and location-based access rules

Cloud Features

• Remote user provisioning
• Temporary and scheduled access
• Lock status monitoring
• Firmware OTA management
• Analytics and reporting dashboard

Mobile Apps

• iOS App (Swift)
• Android App (Kotlin)

Features:

• BLE unlock
• Fingerprint and PIN management
• User invitations
• Access history
• Emergency access handling
• Multi-lock management

Web Admin Dashboard

• Built using React + Node.js
• Organization and building management
• User roles and permissions
• Access analytics
• Device health monitoring

Adequate Infosoft supported the client beyond prototyping into DFM (Design for Manufacturing) and mass production readiness.

Manufacturing Support

• Prototype builds for EVT and DVT
• Flashing tools for production of firmware
• Factory test firmware
• Automated QA test procedure
• Assembly & Calibration Documentation
• Coordination with European/Chinese manufacturers

The final design was certification-ready for CE conformance and local classifications.

• Fully functional multi-access BLE smart lock
• Stable BLE performance with extended range
• Battery life optimized for real-world usage
• Secure cloud-managed access system
• Manufacturing-ready product platform
• Scalable architecture for future variants

The client is now preparing for mass production and commercial rollout across Europe, with Adequate Infosoft as their long-term technology partner.

• Deep expertise in Nordic nRF52 & nRF5 platforms
• Strong embedded + cloud + mobile integration
• Proven experience in BLE security systems
• End-to-end ownership from PCB to production
• Long-term support and scalability mindset

This project showcases Adequate Infosoft’s competence in offering secure, scaleable and ready-for-production BLE smart lock solutions based upon Nordic’s nRF solutions.

From hardware and firmware to cloud and mobile apps, we helped our European client move confidently toward mass manufacturing and market expansion.