Wearable PCB and Firmware Developers You Can Hire

The right team composition depends on what already exists. We can align developers around roles such as:

  • Hardware architect: Defines the MCU, radio, sensors, power tree and test strategy.
  • PCB designer: Creates schematics, stack-up, layout and manufacturing documentation.
  • RF/BLE engineer: Reviews antennas, matching, ground strategy, coexistence and RF results.
  • Firmware developer: Builds drivers, RTOS tasks, BLE services, storage and diagnostics.
  • Low-power engineer: Profiles current and optimizes wakeups, peripherals, radio and sensor schedules.
  • Sensor engineer: Integrates PPG, ECG, temperature, IMU or pressure sensing and signal-quality logic.
  • Validation engineer: Performs bring-up, fault isolation, current profiling and manufacturing-test development.

Roles may be combined or separated for precision analog, rigid-flex, multi-radio or regulated products.

Case Study: ESP32 Wearable Audio Prototype – Mixed-Signal PCB Design Showcase

ESP32 Wearable Audio Prototype
ESP32 · Mixed-Signal

ESP32 Wearable Audio Prototype

We recently partnered with a client developing an ESP32-based wearable audio prototype, focusing on delivering a compact, high-performance mixed-signal PCB design.

The client had desire to have their schematic and PCB designed with a professional electrical engineer with experience in working on cylindrical products that are approximately 10.5 mm high x 46 mm in diameter. Our team completed a complete design from concept to build to assist the customer in the development of a fully functional prototype of the produce.

Project Challenge

The wearable product consisted of a complete mixed signal audio chain that had an ADC and DAC to support a true mixed signal application.

A true mixed signal design is challenging because it must strategically combine different types of circuits (i.e. analog vs. digital) in a small cylindrical form factor and create a low noise environment while still operating within a highly noisy digital switching environment.

The products design included constraints from an ESP32 based microprocessor design, power management requirements, sensor integration, and enclosure design mechanical limitations therefore, the final design had to have the ability to be designed based on an initial prototype run to ensure reliability and acceptable signal integrity.

The Process We Followed

The first step was to review the client's high-level conceptual and technical requirements. We entered into a mutual non-disclosure agreement (NDA) with the client in order to protect any potentially sensitive information related to the product design, enabling us to then gain access to the complete system architecture, audio chain specifications, connectivity requirements, and constraints from all mechanical aspects.

The next step was to develop a complete schematic design by selecting components needed for the audio chain, (i.e., an appropriate set of low-noise ADC/DAC ICs) and designing appropriate passive filtering networks, including power supply filters decoupling and power supply conditioning were critical to the success of the audio chain.

Grounding schemes and routing of signals, as well as isolating the analog and digital domains to minimize inducement of noise or interference, were given careful consideration in the early stages of design.

After the schematic was approved, we transitioned into the PCB layout phase. As part of the PCB layout, we followed industry-standard best practices in mixed-signal design by ensuring:

  • The optimal layout of mixed-signal components (i.e., placing analog and digital components in such a way to minimize crosstalk).
  • The routing of low-noise signals through the PCB.
  • The creation of controlled impedance paths for high-speed digital signals.
  • Adequate heating and electrical decoupling for reliable performance.
  • Provision of test points and connectors to facilitate bench testing.

As we created the layout, we continually worked with the client and adjusted to the real-world limitations of the product and design iterations. Ultimately, both the electrical and mechanical aspects of the prototype product were achieved within the required small cylindrical package.

Outcome

The deliverables for the project included a complete set of schematics and PCB layout drawings for a low-noise mixed-signal audio chain, as well as documents related to the component selection and layout notes used to produce the prototype design.

The client was provided with a prototype-ready design that could be used for testing purposes in a smaller volume before moving onto larger production runs.

The work on this project highlights the experience we bring to designing wearable products using the ESP32 platform, as well as designing PCB layouts for mixed signals.

We were able to produce a feasible product under technical constraints through our extensive knowledge of low-noise mixed signal PCB layouts and the use of high-quality components. Finally, by utilizing proven signal integrity techniques and working collaboratively with our engineering partners, we were able to create a product ready for testing in a real environment.

Relevant Adequate Infosoft Case Studies

Wearable PCB Design Expertise

Miniaturized Schematic and Layout Design

We specialize in creating rigid, flexible, and rigid-flex circuit boards for applications like smart rings, smart bands, smart patches, smart tags, and 'smart clothing' modules. Our work involves using dense placement techniques and working with small pitch technology, controlled return strings, HDI technologies, bend-radiuses, and enclosure-aware test pads. The IPC provides separate guidelines for rigid, flexible, HDI, and RF boards, and customers have a chance to agree about any special requirements.

A board is analyzed as an assembly concerning the height of components, the surfaces facing the skin, the sealing, the charging contacts, flex zones, and accessibility. Early working with mechanical magazines reduces revisions that can affect the performance of antennas, sensors, or batteries.

RF, Antenna and Signal Integrity

It is important to note that human tissues, batteries, displays and metals can disrupt the operation of even the smallest antennas. Developers will need to consider locations for keep-outs, feed and matching networks, transmission lines, return paths and RF test access to ensure proper performance. The performance will only be validated in the given enclosure with the use of representative conditions.

For mixed-signal wearables, it is vital to separate sensitive analog channels from regulators, clocks, haptics and the paths radio currents. The area of concerns in this respect includes grounding, filtering, references and sampling timing.

Batteries, Charging, and Power Configuration

The power system may comprise Li-ion battery, charger, protections, fuel gauge, regulators, load switches and operational mode. The budgeting process is carried out based on operational states instead of relying on average current consumption; hence, thermal limits and peak signal or haptic current are considered.

Embedded Firmware Development for Wearables

Operating Systems, Talented Engineers and Device Operations

The firmware developers are utilizing Nordic nRF52/nRF53, STM32, ESP32 and other qualitative and appropriate formats by means of C/C++, vendor SDKs, Zephyr and other designs working on the principles of an OS.

The architecture guarantees that the separation is made for board support, drivers, services, application logic, connectivity, and diagnostics making the hardware revisions more manageable.

The scope can cover different drivers like I²C, SPI, UART, and ADC, peripherals like sensors, displays, and haptics, as well as others such as storage, touch and gestures, watchdogs, error recovery, manufacturing modes, and diagnostics.

The mobile, cloud, and testing divisions have the access to the interfaces.

BLE Connectivity and Secure OTA

We develop advertising, connections, GATT services, permissions, pairing, bonding, batching and reconnection. Payloads define byte order, timestamps, sequences, errors and versions. Secure OTA can include signed firmware, compatibility checks, resumable transfer, confirmation and rollback where hardware supports it.

Optimization of Low-Power Firmware

Battery life is calculated as a sum of time spent in advertising, transfer, sensing, processing, idle and sleeping. Current profiling uncovers unexpected wakeups, active peripherals, polling and too much radio activity.

Zephyr runtime power management can suspend inactive devices but requires correct implementations of drivers.

Optimization includes interrupts, FIFOs, sensor duty cycles, power domains, BLE parameters and batching. We report test conditions instead of claiming the runtime based on capacity calculations.

Embedded Wearables Solutions: Hardware, PCB & IoT Development – Contact Us

For your next wearable device development requirement, you can hire Embedded Wearables Engineers from us for trusted partner development.

As a full-stack software and hardware development company, we can provide all-in-one IoT wearable solution development. Our Engineers have all the required technical expertise in PCB design, hardware engineering, embedded firmware development and IoT integration to ensure that your wearable solution development will be done seamlessly from concept through the production of the product.

Our IoT Certifications Demonstrating Our Expertise

Our IoT certifications demonstrate our strong expertise in designing and developing reliable connected systems. They validate our skills in embedded hardware, wireless communication, and IoT architecture, ensuring we deliver secure, efficient, and production-ready solutions for modern smart devices and industrial IoT applications.

Microsoft Certified – Azure Solutions Architect Expert

Microsoft Certified – Azure Solutions Architect Expert

Microsoft Certified – Azure IoT Developer Specialty

Microsoft Certified – Azure IoT Developer Specialty

AWS Certified Solutions Architect – Associate – Preeti

AWS IoT

Frequently Asked Questions

Can I hire only a firmware or PCB developer?

Yes. We are able to address one gap in competencies or propose a full team. In systems design, however, multidisciplinary decision-making is preferred as PCB and firmware issues are interconnected.

Can your developers help with our already finished prototype?

Definitely. We are able to carry out an assessment of all documentation, replicate errors, and investigate technical debt. Having a hardware is a real advantage.

Are you involved with EVT, DVT, and production?

Definitely. Our work can cover the start of the product, revision management, tests and DFM coordination, test firmware, and issue resolution for mass manufacturing.

Can you guarantee battery life, BLE range or certification?

No responsible developer should guarantee these before measurement and formal testing. We define targets, engineer toward them and provide evidence under documented conditions. Accredited laboratories and authorized bodies determine certification results.

Who owns the PCB and firmware source files?

The ownership of intellectual property, third-party parts and handover conditions should be discussed and recorded in the contract. The deliverables list may explicitly cover editable design sources, firmware repositories and documentation of the build process.

Ashok Patel
Ashok Patel
Senior Engineering Project Manager
AI/ML, DevOps, Data Science & Automation | IoT & C#/.NET | Azure & AWS Expert | Certified AI & Cloud Engineer | 1,500+ LinkedIn Followers
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