// Embedded systems consultancy for hardware companies.

Embedded Intelligence. From Silicon to System.

Expert firmware, IoT, BLE, and Android engineering. Contracted, remote-first, delivered.

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// What we do

Engineering Services

Full-stack embedded expertise, from bare-metal firmware to mobile applications and cloud-connected systems.

firmware

Embedded Firmware Development

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 & iot

BLE, Wireless & IoT Systems

Custom BLE profile design, Nordic nRF5340/5240 development, and RF protocol implementation, alongside end-to-end IoT product delivery with AWS IoT, cellular data, MQTT, and cloud-connected pipelines.

linux

Embedded Linux & Driver Development

Custom Linux kernel drivers, device tree configuration, platform bring-up, and systems integration on Raspberry Pi and industrial platforms.

mobile

Mobile Application Development

Native Android apps in Java plus Flutter and React Native for iOS and Android, purpose-built to pair with embedded hardware via BLE or network APIs. Payment, EPOS, and BLE service apps with EMV and contactless certification experience.

hardware

PCB Design & Hardware Bring-Up

KiCad schematic capture and PCB layout, PCBA sourcing, hardware validation, and board-level bring-up and debugging.

payments

Payment Systems & POS

Android-based payment terminal development, EMV and contactless certification, acquirer integration, and PCI-aware architecture.

// Flexible workforce

£110k saved versus a full-time hire.

Senior firmware, BLE, Linux, and mobile expertise, on tap.

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 for a fraction of the cost, with the flexibility to scale up or down as your project demands.

  • Start in 1–2 weeks, not months
  • £0 recruitment fees
  • Scale up or down monthly
  • No single point of failure
  • Full team, one contract
  • 30-day notice, no lock-in
Compare retainer to full-time hire
Retainer
Full-Time
Annual cost
From £36k
£111k+
Time to start
1–2 weeks
3–6 months
Skill breadth
Full team
One person
Recruitment fees
£0
£13k+
Exit flexibility
30 days
3–6 months
Absence cover
Team covered
Project stalls

// Also from ETL

Products in the wild.

Two production tools built from the same engineering practice we sell.

// simupay

Open Beta

SimuPay

Multi-protocol acquirer host simulator for payment terminal developers, QA engineers, and certification teams. Replaces live banking connections during development.

  • APACS 70, Amex & ISO 8583
  • Scenario builder & rules engine
  • TLS encryption & MAC support
Try SimuPay free

// onebox lite

Shipping

OneBox Lite

Rugged industrial data-acquisition platform. Four protected analogue inputs, three MOSFET load switches, Wi-Fi + BLE 5, RS-485, USB-C, microSD, onboard temperature, humidity, and 3-axis accelerometer sensing.

  • Wireless-first industrial telemetry
  • Interactive 3D specification
  • Production hardware available
Explore the 3D brief

// Technology stack

Technology Stack

Battle-tested across a breadth of embedded architectures, protocols, and development ecosystems.

Languages

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

Embedded C/C++JavaPythonC#DartJavaScriptAssembly

RTOS / OS

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

FreeRTOSEmbedded LinuxZephyrNuttXTiny-OS

Hardware 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

ARM Cortex M4/M7AtmelNordic nRF5340/5240ESP32Raspberry PiPICAmbiq

Protocols / Comms

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

BLECANSPII2CUARTRS485MQTTTCP/IPWiFiGPRS2.4GHz RF

Mobile

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

Android (Java)FlutterReact NativeiOS

Tools & Standards

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

KiCadMISRA CEMVContactlessPC-LintQT Framework

IoT Platforms

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

AWS IoTTelenorMQTT Brokers

// What we build

Selected Work

Real-world engineering across industries: from sensor acquisition and wearable devices to payment terminals and vehicle systems.

// Featured Product · Interactive 3D Brief

OneBox Lite

A rugged, wireless-first industrial data-acquisition platform. Four protected analogue inputs, three high-current load switches, and a full Wi-Fi + BLE stack on one board. Explore the specification with an interactive 3D model.

View 3D Brief →
01 / 06

Industrial Sensor Acquisition

Bespoke fibre-optic enabled data logger for demanding sensor acquisition environments, feeding AI-based feature detection. Linux-based custom kernel drivers deliver high-accuracy sensor sampling on downwell toolchains with AI model integration.

Embedded C Linux Drivers Kernel Fibre Optic AI/ML Data Pipeline
02 / 06

Wearable & Fitness

Nordic nRF5340-based BLE transmitter/receiver with real-time SD card storage and optical + accelerometer sensors. ESP32 firmware reverse-engineered a BLE device profile for Zwift compatibility, paired with a custom Android BLE service app.

nRF5340 ESP32 BLE Zephyr Android Zwift Sensors
03 / 06

Automotive

ARM Cortex M7 in-vehicle ECU with CAN bus integration, FreeRTOS, and QT-based touchscreen keypad on Linux.

ARM Cortex M7 CAN Bus FreeRTOS QT Linux
04 / 06

Sports Technology

ESP32 IoT device measuring professional football pitch surfaces, with React Native mobile app and web platform sync.

ESP32 React Native IoT AWS
05 / 06

Payments / FinTech

Android payment applications for the UK market; full EMV/contactless certification with multiple acquirers.

Android EMV Contactless Java
06 / 06

Tracking & Telematics

CAN bus RFID authentication device for forklift fleet management, trialled with a major UK logistics provider. Zephyr/FreeRTOS BLE asset trackers and environmental sensors extend the platform with cellular data sync.

CAN Bus RFID BLE Zephyr FreeRTOS Cellular Embedded C

// A selection of clients we’ve delivered for

// About

Who We Are

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.

30+ products shipped, 15+ silicon architectures (Nordic, ESP32, STM32, ARM Cortex), 20+ years of practitioner experience.

// Get in touch

Start a conversation.

We take briefs selectively: the ones where deep embedded expertise changes the outcome. Tell us yours and we’ll route you to the right engineer, typically within one business day.