Expert firmware, IoT, BLE, and Android engineering — contracted, remote-first, delivered.
// What we do
Full-stack embedded expertise — from bare-metal firmware to mobile applications and cloud-connected systems.
firmware
Bare-metal and RTOS-based C/C++ firmware for ARM Cortex, Atmel, PIC, ESP32, and Nordic nRF platforms. From board bring-up to production-ready code.
wireless
Custom BLE profile design, Nordic nRF5340/5240 development, MQTT/IoT integration, and RF protocol implementation for connected products.
linux
Custom Linux kernel drivers, device tree configuration, platform bring-up, and systems integration on Raspberry Pi and industrial platforms.
iot
End-to-end IoT product development including AWS IoT, cellular data, sensor acquisition, and cloud-connected data pipelines.
mobile
Native Android apps in Java, including payment applications, BLE service apps, and EPOS integrations with EMV/contactless certification experience.
hardware
KiCad schematic capture and PCB layout, PCBA sourcing, hardware validation, and board-level bring-up and debugging.
cross-platform
Flutter and React Native development for iOS and Android, purpose-built to communicate with embedded hardware via BLE or network APIs.
payments
Android-based payment terminal development, EMV and contactless certification, acquirer integration, and PCI-aware architecture.
// Flexible workforce
Why companies choose retainers over full-time hires.
Hiring a full-time embedded engineer costs upwards of £110k in year one when you factor in recruitment, NI, pension, equipment, and bench time. A retainer with ETL gives you access to a full team of specialists — firmware, BLE, Linux, mobile — for a fraction of the cost, with the flexibility to scale up or down as your project demands.
// Our product
Test every payment scenario. Ship with confidence.
SimuPay is our multi-protocol acquirer host simulator built for payment terminal developers, QA engineers, and certification teams. It replaces the need for live banking connections during development — giving you a real-time, controllable test environment that speaks your terminal's language.
// Technology stack
Battle-tested across a breadth of embedded architectures, protocols, and development ecosystems.
Deep proficiency in systems-level and application languages. Our core strength is in embedded C/C++ for bare-metal and RTOS environments, complemented by Java for Android platforms, Python for tooling and test automation, and modern mobile languages like Dart for cross-platform work.
Technologies
Extensive experience with real-time operating systems for deterministic embedded workloads. We architect task scheduling, interrupt handling, and resource management across FreeRTOS, Zephyr, and custom Linux builds — choosing the right OS for each project's latency, memory, and power constraints.
Platforms
Hands-on board-level expertise across ARM Cortex, Nordic, Espressif, and legacy architectures. From initial schematic review through bring-up, peripheral configuration, and production firmware — we work directly with silicon, not just abstractions on top of it.
Architectures
Fluent in the full spectrum of embedded communication — from chip-level buses (SPI, I2C, UART) through industrial fieldbus (CAN, RS485) to wireless stacks (BLE, WiFi, MQTT). We implement protocol layers from scratch when needed and optimise for throughput, latency, or power as the application demands.
Protocols
Native and cross-platform mobile development purpose-built to pair with embedded hardware. Our Android apps handle BLE service discovery, real-time data streams, and payment terminal integration. Flutter and React Native projects extend reach to iOS while maintaining tight hardware coupling.
Frameworks
Production-grade engineering demands proper tooling and compliance. We design PCBs in KiCad, enforce MISRA C for safety-critical code, certify against EMV and contactless payment standards, and use static analysis tools like PC-Lint to catch defects before they reach hardware.
Tools
End-to-end IoT system integration connecting edge devices to cloud infrastructure. We build device-to-cloud data pipelines using AWS IoT Core, cellular connectivity providers, and MQTT broker architectures — handling provisioning, OTA updates, and telemetry at scale.
Platforms
// What we build
Real-world engineering across industries — from sensor acquisition and wearable devices to payment terminals and vehicle systems.
Sensor Acquisition
Bespoke fibre-optic enabled data logger for demanding sensor acquisition environments, feeding AI-based feature detection.
Wearable Technology
Nordic nRF5340-based BLE transmitter/receiver with real-time SD card storage and optical + accelerometer sensors.
Fitness / IoT
ESP32 firmware reverse-engineered a BLE device profile for Zwift compatibility, plus a custom Android BLE service app.
Industrial / Energy
Linux-based custom kernel drivers for high-accuracy sensor sampling on downwell toolchains with AI model integration.
Automotive
ARM Cortex M7 in-vehicle ECU with CAN bus integration, FreeRTOS, and QT-based touchscreen keypad on Linux.
Sports Technology
ESP32 IoT device measuring professional football pitch surfaces, with React Native mobile app and web platform sync.
Payments / FinTech
Android payment applications for the UK market; full EMV/contactless certification with multiple acquirers.
Fleet Management
CAN bus RFID authentication device for forklift fleet management, trialled with a major UK logistics provider.
Asset Tracking
Zephyr/FreeRTOS BLE asset trackers and environmental sensors with cellular data sync.
// About
Embedded Technologies Limited is a specialist engineering consultancy offering deep expertise across the full embedded product lifecycle. From initial hardware design and PCB layout through firmware bring-up, BLE/IoT integration, and mobile application development, we deliver production-grade solutions across industries including medical technology, sports performance, vehicle systems, and payment terminals.
We work remotely and integrate seamlessly with client teams — whether the requirement is technical delivery, architecture guidance, or hands-on development from concept to certification.
// Get in touch
Have a project in mind? Share the details and we will get back to you promptly.
Thank you for getting in touch. We will review your project brief and respond within one business day.
Typical response within 1 business day. All enquiries treated in confidence.