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Electronic boards, from schematic to the field.

I’m Geoffrey Fournier, an independent R&D engineer: I design and verify electronic boards, their radio and their firmware, through to production. My specialty: battery-powered field devices, from wildlife trackers to research instruments at sea. 13 years in the trade, methods from regulated industries, and a passion for wildlife and the environment.

Start with a fixed-price design review: from €1,600 excl. VAT, report in about a week. Then design and build by milestones, or team extension on a daily rate.

Get my board reviewedDiscuss a project

or write to contact@coxpert.com

For research labs, conservation NGOs, hardware startups and regulated industries. Work with Arribada, CLS, CNRS (LIRMM), Ifremer and IDOCEAN.

On screen: Linkit v4, an open-hardware satellite tracker board (CERN OHL), simplified. Oscilloscope traces are illustrations.

Electronic boards

Boards designed to last for years in the field and to be built in volume: from a 2 × 2 cm module to a dense board of 8 layers or more, delivered with a production package ready for the assembler.

  1. Multilayer routing

    Schematic and layout, rigid or flex, RF lines and antenna area included; parts placed for the enclosure and for assembly.

  2. Low power

    Supplies and sleep modes sized for the target battery life, then measured.

  3. Charging and harvesting

    Solar, wireless, Ethernet (PoE), piezoelectric or USB power; charging restarts from a dead battery.

  4. Sensors

    Every common sensor family, from motion and depth to light, infrared and ultrasound: the board wakes on an event, measures and logs it.

  5. Production files

    A complete manufacturing package, then follow-up with the assembler: BOM cost and availability, parts shared across projects, board acceptance.

Radio and antennas

Satellite, cellular, long-range radio, Bluetooth, or no radio at all for a logger read on site: the choice depends on location, cost and energy. Antenna and RF chain are tuned, then checked in the field.

  1. Antennas

    Choice, placement, ground plane and enclosure; matching measured, not estimated.

  2. RF chain

    Filtering, amplification and matching between module and antenna: every decibel lost costs range and battery.

  3. Radio modules

    Radio modules that are already certified: satellite (Argos, Kinéis, Iridium), LoRa, Bluetooth, GNSS; cellular (LTE-M, NB-IoT) on request.

  4. Coexistence

    Several radios on one board, placed and routed so that none deafens the others.

Embedded software and tools

The firmware turns a board into a product: it reads the sensors, drives the radios, manages power and updates in the field. Desktop and web tools configure the device and read back its data.

  1. Firmware

    Written for the microcontroller’s constraints: sleep, real time, updates in the field.

  2. Drivers

    Each sensor and radio module speaks its own protocol; reusable drivers let the microcontroller talk to each one.

  3. Tests

    Code tested on a computer at every change, then on the board.

  4. Tools

    Desktop or browser apps to configure the board, update it and read its data.

Validated by measurement

A board is validated when measurements confirm the specification, on the bench and then in the field. The method comes from medical devices, aerospace and rail: written requirements, traceability and tests at every milestone, as a V-model, in agile iterations, or both.

  1. Requirements

    Requirements written together and linked to their tests; each milestone closed by a review.

  2. Design rules

    Boards drawn to IPC standards, easy to build and test; code to strict rules, analyzed and reviewed.

  3. Bench verification

    Bring-up supply by supply, each function checked, power budget measured per state, any gap explained.

  4. Field validation

    On the animal, at sea, at a research station: link, positions and battery life checked where the device lives.

  5. Production tests

    A test bench, delivered with the board, programs, checks and logs every board, or a sample per batch.

Quality and standards: every result traced to a requirement and a test report. Standards practiced: ISO 13485, IEC 60601, IEC 62304 (medical, on the Oscult ultrasound scanner); RED for CE marking, FCC, ETSI EN 300 220, EN 301 489 (radio and EMC); IPC-⁠2221, IPC-⁠7351, IPC-⁠A-⁠610 (boards). Aerospace: work within a DO-⁠178C and DO-⁠254 framework. Practices: MISRA C-style coding rules, static analysis, DFM and DFT.

Three offers

A fixed price when the scope is known, a quote by milestones for a whole device, a daily rate for open-ended needs.

  1. Fixed price

    Design review

    Reviewed from your files (Altium, KiCad or PDF): architecture and technical choices, schematic, layout, BOM (cost, availability, alternatives) and power budget. Delivered: a written report, each issue located by sheet and designator and ranked (blocking, to fix, advisory), then a call to walk through it. Firm price and delivery date confirmed in writing after reading your files.

    Request a review
    Focused
    One area: €1,600 to €2,400 excl. VAT, about 1 week
    In-depth
    Whole board, DFM and DFT: €4,000 to €7,000 excl. VAT, 2 to 3 weeks
    Urgent
    Priority slot, +50 %

    Included: one check of your fixes, within 30 days of the report.

  2. Custom quote

    Design and build

    From requirements to production files: architecture, schematic, layout, prototypes, bring-up, firmware, tests and field trials, then manufacturing follow-up if you wish. First milestone: a fixed-price scoping phase (requirements, architecture, estimated power budget, firm quote for the rest), deducted from the project if it goes ahead. A board designed elsewhere starts with an in-depth review.

    Discuss a project
    Milestones
    Scoping, schematic, layout, prototypes, trials, final package
    Delivered
    Sources, Gerbers, BOM, firmware repository, test reports
    Price
    Scoping €1,600 to €2,400 excl. VAT (deducted), then a written quote by milestones

    Each milestone closes with a review and the files delivered to you.

  3. Daily rate

    Team extension and consulting

    A period inside your team, advice on an architecture or a component choice, or training for your engineers.

    Discuss team extension
    Format
    Daily rate, for a set period, in a written quote
    Topics
    Boards, radio, firmware, test benches, method
    Where
    Remote, from Réunion Island

    Working hours adapted to your team’s time zone.

Review prices: a focused review (schematic, power, RF, layout or BOM) depends on complexity; an in-depth review before production, on the board (layers, radios, HDI or flex). Several boards or a complete system: quoted on request. Lead times count from complete files. A focused review’s price is deducted from an in-depth review or a project ordered within 30 days.

Commitments: a written quote before any work; an NDA before any file exchange, if you wish; design, code and test results are yours, or published open source if you prefer. CII approval (French innovation tax credit for SMEs, on CoXpert’s invoices): renewal in progress, status on request.

Work

Open-source projects, all for Arribada, with their GitHub repositories; a name without a link is not published yet. For other clients and employers: the project and the role only.

  • Linkit v4 board, top and bottom: GNSS antenna, Argos SMD module, connectors
    Linkit v4, top and bottom
  • Argos SMD satellite module, 2 × 2 cm, soldered on its host board
    Argos SMD module, 2 × 2 cm
  • Two sea turtle tags: a Linkit v4 board, cells and a whip antenna sealed in clear epoxy
    Sea turtle tag, sealed in epoxy
  • LoRa SMD module built around a RAK3172 system in package
    LoRa SMD module, 2 × 2 cm
  • The two boards of the RSPB bird tracker
    RSPB bird tracker boards
  • 3D render of the Marlin system, top and bottom: the I/O board for Raspberry Pi CM5 with its power board, from the Altium design files
    Marlin system: I/O and power boards, 3D render

Boards made for Arribada: photos by Arribada, renders from the design files.

Open source

  1. 01
    Linkit v4 satellite tracker

    Open satellite tracker for Argos and Kinéis, made with CLS: the board on screen.

    Board, firmware (main author), tool

    linkit-v4-hw · linkit-v4-core · CLS-Argos-Linkit-pylinkit · CLS-Argos-Linkit-CORE · CLS-Argos-Linkit-Hardware

  2. 02
    Argos SMD module

    A 2 × 2 cm satellite module pre-certified by CLS, with firmware, Zephyr driver and host boards.

    Boards, firmware (main author), driver (co-written)

    argos-smd-hw · argos-smd-at-kineis-firmware · argos-smd-driver-zephyr · featherwings-argos-smd-hw · gps-smd-m10 · argos-smd-test-arduino · standalone-smd-hw

  3. 03
    Surface and dive tracker

    Argos tracker on a flex circuit with a built-in antenna; it transmits when it surfaces.

    Board and firmware

    op-tracker-hw · op-tracker-firmware

  4. 04
    LoRa 868 MHz modules

    Two 2 × 2 cm LoRa modules, low or high power, interchangeable with the Argos module.

    Hardware design

    lora-smd-hw · lora-smd-rak3172sip

  5. 05
    Bird tracker with mortality detection

    Argos bird tracker that flags when the animal stops moving, with its flexible solar panel support.

    Hardware design

    rspb-tracker-hw · rspb-pv-support

  6. 06
    Marlin system boards

    Input-output board (PCIe, Ethernet) and 12/24 V power board around a Raspberry Pi CM5.

    Hardware design

    marlin-core-hw · marlin-pwr-hw

  7. 07
    Tracker management platform

    Web and desktop app to configure trackers, estimate battery life and monitor their data.

    Design and development

    arribada-web-platform

Private: clients and employers

  1. 08
    Marine research

    Instruments for research projects at sea.

    Electronics and firmware · CNRS (LIRMM), Ifremer, IDOCEAN

  2. 09
    Handheld ultrasound scanner

    Oscult: FPGA beamformer board, power board connected to an iPad, C firmware; EMC tests passed; ISO 13485, IEC 60601 and IEC 62304 practiced toward CE marking (in progress).

    Hardware lead · Oscadi (employee)

  3. 10
    Aircraft engine monitoring

    Bearing vibration analysis on ARM and DSP.

    Internship (2012), then algorithm optimization (2013) · Safran

  4. 11
    Railway station remote control

    Software in Ada, industrial protocols in C++.

    R&D engineer (2013 to 2015) · Systerel, for Alstom

Other private projects: details and references on request.

Portrait of Geoffrey Fournier

One engineer, the whole board

CoXpert is one engineer: me, Geoffrey Fournier, independent since 2019. I do every review and every design myself, from schematic to field trial.

Based in
Réunion Island, France; remote work
Education
Engineering degree in embedded systems (ECE Paris); BSc in signal processing (Aalborg University)
Time zone
UTC+4: 2 to 3 h ahead of Paris, 3 to 4 h ahead of London, 1 h ahead of Nairobi
Languages
English, French
  1. Aerospace and railSafran; Systerel, for Alstom2013 · 2014
  2. Medical devicesOscadi2015 · 2018
  3. Wildlife tracking and marine researchCoXpert, independent; Arribada since 20232019

Registered in France: sole proprietor (entrepreneur individuel, micro-entreprise), SIREN 850 085 804.

Frequently asked questions

Do you sell ready-made trackers?

No: each device is designed and built for its project, even from a bare idea. Start with a call, then the fixed-price scoping phase described under Design and build; the open-source boards under Work show what has been built so far.

Another provider designed the board. Can you review it before production?

Yes: a board designed elsewhere starts with an in-depth review, whose report your team or the original designer can act on directly.

What does a project quote include?

The milestones, the deliverables and the number of prototype iterations. An extra iteration is quoted separately, as is prototype manufacturing (boards, parts, assembly). After delivery: a 3-month warranty (any defect in the delivered work fixed at no cost), then support billed for time spent or as a monthly plan.

Do you offer terms for NGOs or open-source projects?

On request: say so in your first message, with the project and what will be published.

Is the design ready for certification (CE, FCC)?

It is prepared for it from the schematic onward: RED, FCC and EMC requirements are taken into account. The compliance tests themselves are run by an accredited laboratory.

We work under ISO 13485. Can you meet our quality requirements?

Yes: the deliverables are written to your requirements (requirements, traceability, test reports, design reviews), and your quality system stays yours. ISO 13485, IEC 60601 and IEC 62304 were practiced on the Oscult ultrasound scanner, which passed its EMC tests.

Who pays for network subscriptions?

You do: satellite and network subscriptions (Argos, Kinéis, Iridium, LoRaWAN, cellular) are in your name, with the operator.

How is the work invoiced?

In euros, excluding VAT: by milestone for a project, on delivery for a review. VAT at 8.5 % for clients on Réunion Island, otherwise as your country’s rules require.

Who handles our files, and where?

Only me, with no subcontracting. I work in France (Réunion Island is a French department, under French and EU law), under NDA if you wish, and in your own tools and servers if your policy requires it (Altium Designer preferred).

You work alone: what if you are unavailable?

Sources and documentation are delivered at every milestone, in standard tools (Altium or KiCad, Git): another engineer can take over, and your project never depends on a file you do not have.

You are on Réunion Island: how do calls and prototypes work?

I set calls in your team’s working hours. Prototypes: when I build them as part of the project, I order them directly; when you build them, I cover shipping to my bench.

Do you design the enclosure?

No: the enclosure is designed by your mechanical team or by a partner mechanical designer. The board is laid out to fit it and delivered with its 3D model (STEP).

Can you run the field trials?

Yes, bench first, then in the field, with partners on Réunion Island or on your site. Travel costs are charged to the project.

A board to review, or a device to build?

Describe the project, its stage and timeline, with any files you can share; NDA first if needed. Then a call and a written quote.

I reply within 2 business days, with the earliest start date. My schedule is currently busy: tell me when you need the work.

contact@coxpert.com

Book a call about your project

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