Case Study
ParcelPoint Smart Locker
A complete embedded solution for automated parcel management — from custom PCB hardware to a cloud-connected Qt/QML touchscreen application.
EMBEDDEDLogistics3 months2024
Case Study
A complete embedded solution for automated parcel management — from custom PCB hardware to a cloud-connected Qt/QML touchscreen application.
The Challenge
Develop a secure, reliable automated locker system that works 24/7 in outdoor environments, handles payment processing, provides real-time status updates, and offers an intuitive user experience.
The system needed to handle the full parcel lifecycle — drop-off by couriers, secure storage, SMS notifications to recipients, and M-PESA payment on collection — all from a ruggedised outdoor unit.
Beyond the hardware, the challenge included building a cloud backend for locker management, a Qt/QML touchscreen UI for the kiosk, and a mobile app for operators — all integrated and deployable within three months.
Hardware Design
We designed a multi-board architecture using industrial-grade components rated for outdoor environments. The main controller board handles lock actuation, payment terminal integration, and 4G LTE connectivity.
Power supply design covers 12V/5V/3.3V rails with surge protection and EM control circuits for reliable solenoid operation. Each locker compartment has an independent lock driver with fault detection.
The PCB layout was optimised for manufacturing, with full DFM review and a BOM structured for local sourcing in Kenya where possible.
Firmware Development
The firmware runs on a Linux-based embedded OS with a multi-threaded architecture handling lock control, payment processing, cloud sync, and UI communication simultaneously.
OTA update capability allows remote firmware deployment without physical access to the unit. A comprehensive error recovery mechanism ensures the system returns to a safe state after any fault.
Real-time monitoring pushes health data — door status, payment terminal state, temperature, connectivity — to the cloud backend every 30 seconds.
User Interface
The kiosk UI was built with Qt/QML targeting a 10-inch industrial touchscreen. The interface supports multi-language operation and was designed for accessibility, with large touch targets and clear visual feedback.
Offline capability ensures the UI remains functional during connectivity gaps — transactions are queued and synced when the connection is restored. All interactions are logged for analytics.
The responsive design adapts to different screen orientations and ambient light conditions, with automatic brightness adjustment for outdoor readability.
Technology Used
Custom PCB · Multi-board architecture
Linux Embedded · C/C++ · Multi-threaded
Qt / QML · 10" Industrial Touchscreen
RESTful API · Real-time Notifications
M-PESA · Daraja API
4G LTE · MQTT · SMS (Africa's Talking)
Work With Us
Every project starts with a conversation. Tell us your constraints and goals — hardware, firmware, or full stack — and we'll tell you how we'd approach it.