Firmware development services for wearables, voice devices and trackers
Duobay writes embedded firmware for wearables, voice and recording devices, and LTE and GNSS trackers: BLE, signed OTA updates and per-device provisioning. The source goes into your own repository with build instructions, at every paid gate.
What we build firmware for
Three product types, written alongside the board and enclosure we design. This is not general embedded outsourcing.
Rings, pendants, pins and badges
Encode, encrypt and buffer audio to flash. Send it to the phone over BLE with resume after a dropped connection, or upload over Wi-Fi or LTE-M. Recording starts from a button, and the recording light stays on whenever the mic is live.
See the product page →Health wearablesBands, rings and watches
Sensor duty cycling and sleep states on low-power Bluetooth LE SoCs, measured per mode. Signed OTA over BLE with rollback, so sensor and algorithm changes can ship after launch. General wellness only, no medical claims.
See the product page →LTE and GNSS trackersBattery trackers that report to your cloud
GNSS fix, LTE attach and MQTT over TLS to your broker. Per-device certificates where you hold the CA, configurable report intervals, motion, geofence and low-battery events.
See the product page →Reference designs: voice-capture badge and LTE and GNSS tracker.
Firmware by gate
Firmware ships at two gates. Each one ends with files in your repository, and you can stop after either. The full gate sequence is on how it works.
| Stage | Firmware work | What you get |
|---|---|---|
| Gate 1 · Works-like prototype 3–6 weeks | First firmware on the target silicon, running on proven modules on a custom carrier board. Power, latency and RF measured on the units. | First firmware in your repository. Measured power, latency and RF numbers. Go / adjust / stop recommendation. |
| Gate 2 · EVT · first custom PCB 6–10 weeks | Firmware on the custom PCB after bring-up, with OTA updates and provisioning. | Firmware repository with build instructions. EVT test report. Every electrical, mechanical and firmware file for the EVT design. |
Exit at Gate 1: Stop and keep the units and all source files. Exit at Gate 2: Stop and take the full design package to any factory.
How firmware development runs
Every step ends with a measurement on real units, so you decide on data. Embedded firmware development here means these six steps, in this order.
Bring-up on the board
Power rails, clocks, radio and sensors checked board by board. You receive the logs.
Power profile
Current per mode measured on real units and turned into a runtime estimate you can check.
RF numbers
Conducted power and pre-scan results, so the firmware radio settings are checked before a formal lab slot.
Signed OTA
Update images are signed, and the device rolls back if an update fails. Your backend or app triggers the update.
Data integrity
Device-to-app-to-cloud transfer is tested with interruptions, full storage and low battery.
Test report
Results from these steps go into the EVT test report at Gate 2.
Your repository, your keys
Firmware source goes into your repository with build instructions. If you stop at any gate, you take the files with you and a new team can build the same image. Per-device keys are provisioned on the line, and the signing keys and certificate authority stay with you. We keep no copy after handover.
The contract assigns the IP and every source file to you at each paid gate. Read how that works in who owns source files under a US contract, and what the handover contains in the SBOM and source handover checklist.
Engineering guides for this work
Circuit Breaker Pattern for Device Fleets and Cloud Retries
Read →PlatformsSWD vs JTAG: Debug Ports, Connectors and Probes
Read →PlatformsEmbedded Programming Workflow for Connected Device Firmware
Read →ProcessFirmware Development Services: A Buyer's Guide
Read →ProcessFirmware Engineer: Hire, Contract or Outsource?
Read →PlatformsWhat Is an Embedded System? Parts and Examples
Read →Firmware: common questions
How do OTA updates work?
Update images are signed, and the device rolls back if an update fails. Over BLE the phone app delivers the image. On cellular builds your backend triggers the update. The signing keys are yours.
Who owns the firmware source?
You do. The firmware source goes into your repository with build instructions, at every paid gate. Details are in who owns source files under a US contract and the SBOM and source handover checklist.
What do you need from us to start?
A description of the product, the target runtime and form factor, the phone app or cloud endpoint the device talks to, and any dev-kit demo or board you already have. An engineer reviews it before the first call. A Duobay engineer replies within 1 business day.
Do you take general embedded firmware projects?
No. We write firmware for wearables, voice and recording devices, and trackers, as part of a device we also design. We do not take firmware-only outsourcing for unrelated products.
Next step. Send us the product description, a dev-kit demo or a board. An engineer reviews it before the call. A Duobay engineer replies within 1 business day.
Written by the Duobay engineering team. Duobay is a service of Aximora Labs Inc., a US company. Contact is in the San Francisco Bay Area, and the engineering team is in Shenzhen. About Duobay.