Open & Hackable Wearable Body Monitors

Last updated 2026-09-21 · updated weekly by an automated research job · run #8.

The verdict

The current state of the art, as of 2026-08-18 (confidence unverified):

The open-firmware wearable ecosystem remains anchored by Bangle.js 2 as the most mature shipping device with PPG, accelerometer, GPS, and a stable hardware revision. Newer platforms like SensWear and HealthyPi 6 are emerging but are not yet shipping or proven. For a slim wrist monitor with PPG, accelerometer, and BLE, a custom PCB or modifying an existing open platform is still required, as no shipping device combines all three with an ambient-light sensor.

What triggered or contributed to this call:

• 2026-08-18 — SensWear project page on Hackaday.io confirms design files to be published on EasyEDA. (update, vendor-claim)
• 2026-08-18 — ProtoCentral unveils HealthyPi 6, powered by STM32H7 microcontroller. (discovery, secondary)

Contenders:

• Bangle.js 2 — Most mature shipping open smartwatch with PPG, accelerometer, GPS, stable hardware, and active community.
• HealthyPi Move — Shipping open-source watch form factor with extensive biosensing (ECG, PPG, SpO2, EDA).
• PineTime — Fully open hardware with community firmware, though original model lacks some sensors; Pro version announced.
• VitalTrack PPG&Motion — Closest to target pod form factor (synchronized PPG + IMU stream) but campaign status unconfirmed.

What this is, and how it works

This page is generated, not written. A scheduled job runs weekly on a machine in a homelab. Each run it:

1. Searches the open web for both the products already tracked here and for category-level terms designed to turn up ones we've never heard of.
2. Feeds those results to a language model along with everything already on this page, and asks it what is genuinely new. Finding nothing is an acceptable answer, and most runs should find little.
3. Writes the result into a versioned JSON dataset (data/live-research/open-wearables.json) and commits it. This page is re-rendered from that file.

So: a machine wrote the prose here. Every changelog entry carries at least one source link, and every item and entry carries a confidence label:

• primary-source — vendor documentation, a published paper, or a regulator.
• secondary — reputable press.
• vendor-claim — marketing or an unreplicated vendor statement.
• unverified — a single low-quality source, usually auto-discovered.

Any label weaker than primary-source is printed beside the finding, so an unflagged row is a primary source. A tracker that hides its own uncertainty is worse than no tracker.

What this is not. Not medical advice. Not a review site — nothing here has been tested in our hands. No affiliate relationships, no sponsored placements, nothing bought. Vendor claims are attributed to the vendor rather than restated as findings. Where a price, a date, or a regulatory status is unknown, it is left blank instead of guessed.

What's new

No new developments since 2026-08-31, the date of the most recent entry below. That is a real finding, not a gap: this beat moves in weeks and months.

The last 30 days

AsteroidOS 2.0 launched, offering an open-source Linux distribution for smartwatches. This is a community-driven firmware project, not new hardware, and its utility depends entirely on having a supported device to flash. Separately, the PineTime Pro's rumored specs—including an AMOLED display and GPS—were detailed in a secondary report; this remains an upcoming device from Pine64, and the claims are unverified vendor or community speculation.

Two new open-source hardware projects appeared. The H-Watch, from an academic group, is a fully published platform featuring NB-IoT for direct cellular connectivity, a notable but power-intensive alternative to BLE phone relay. The Open-SmartWatch project also published its hardware files and 3D-printable designs. Both are in early stages and their viability as stable, slim wrist-worn platforms is unverified.

On the component side, the ESP32-S3-MINI-1 module's product page was updated with bulk ordering details, cementing it as the go-to compact, certified wireless module for custom builds. ProtoCentral's HealthyPi 6 campaign page went live on Crowd Supply, listing expansion modules, but this is a vendor claim for an unshipped dev platform, not a wrist-worn monitor.

For someone building today, the landscape of genuinely open, stable wrist hardware remains unchanged: Bangle.js 2 and the original PineTime are the only proven options. The new announcements are either firmware for existing hardware or early-stage projects that add complexity (like direct cellular) without solving the core problem of a reliable, slim, sensor-equipped open device.

Written 2026-09-21 from the changelog below, not from a fresh search.

Drawn from: nothing — there are no changelog entries in the last 30 days.

The last year

The last year saw a steady trickle of new open-source hardware announcements, but the field remains defined by a handful of established, reliable products. The biggest movement was in new development platforms. The VitalTrack PPG&Motion sensor pod, a near-perfect match for a slim, wrist-worn telemetry device, remains "coming soon" on Crowd Supply with no campaign launch or shipping confirmation. ProtoCentral, however, successfully funded and began shipping the HealthyPi Move, a full-featured open-source biometric watch, and announced its successor, the HealthyPi 6, on Crowd Supply. Separately, the SensWear platform, based on Nordic's latest nRF54L15 chip, was announced with plans to publish design files. For someone building today, these are vendor claims of future capability; the only new, buyable open hardware for body monitoring is the HealthyPi Move.

In established open devices, the story is stability. The Bangle.js 2 continues as the benchmark for a fully open, community-supported wrist device with published schematics and a stable hardware revision. The PineTime saw a restock of its original model, but the major news was the announcement of the PineTime Pro, promising an AMOLED display, GPS, and new sensors. This is still a future product based on secondary reports from PINE64's announcements. The Watchy remains available but lacks any PPG sensing, keeping it outside the core body-monitor scope. A notable negative finding from a Hackaday article confirms the tracker's anchor premise: even the reverse-engineered Mi Band 10 with custom firmware is a fragile hack against a closed hardware platform that will silently revise.

On the component side, progress is incremental but concrete. Espressif solidified the ESP32-S3-MINI-1 as the go-to certified module for compact custom designs, and M5Stack introduced the M5StampS3 BAT Module, which uniquely adds proper battery charge management to the Stamp lineup. Cheap MAX30102 breakouts remain ubiquitous for prototyping. For connectivity, the baseline conclusion held: BLE-to-phone relay is the only practical choice for a power-constrained wrist device. While Meshtastic documentation confirmed support for health telemetry, and academic projects like H-Watch proposed NB-IoT cellular, these require substantial gateway infrastructure or sacrifice too much size and battery life for the target slim wrist form factor.

The most promising technical development came from academia, not hardware: the publication of Pulse-PPG, an open-source foundation model pre-trained on a massive dataset of raw PPG signals. If its performance holds, this could significantly lower the barrier to extracting useful biomarkers from the PPG sensors already on these devices. However, it remains an unverified study without integration into any shipping platform. Similarly, software projects like AsteroidOS 2.0 and the Open-SmartWatch project expand firmware options but don't address the core hardware scarcity. The year ultimately reinforced that for a reliable, slim, open body monitor, you are still choosing between the mature Bangle.js 2, the newly shipping HealthyPi Move, or designing your own PCB around components like the ESP32-S3-MINI-1 and a MAX30102.

Written 2026-09-07 from the changelog below, not from a fresh search.

The ones that mattered:

• 2026-08-10 — Pulse-PPG open-source foundation model for wearable PPG signals published. (study, primary-source)

All time

The field for open, hackable wrist-worn body monitors remains defined by a scarcity of viable hardware. The standing finding holds: consumer fitness bands are a dead end due to silent hardware revisions and locked firmware. The only reliable paths are devices designed open from the start or building from breakout components. Since tracking began, the most significant shift is the arrival of a new generation of fully open biometric monitors, moving beyond simple heart-rate sensing.

What works is a short list. For a complete, slim, open device, the Bangle.js 2 remains the only proven option with a stable hardware revision, published schematics, and an active community. It lacks an ambient light sensor but otherwise matches the target spec. For a component-based build, the MAX30102 bare breakout modules are the commodity PPG sensor, dirt-cheap and reliable. Connectivity is solved: BLE-to-phone relay is the baseline, proven by Bangle.js and every commercial band. It offloads power-hungry WAN connectivity to a device the user already carries.

What does not work, or remains unproven, is more numerous. Cellular/LTE direct-on-wrist is correctly considered dormant; the battery and size penalty is prohibitive for a slim monitor. LoRaWAN and ESP-NOW are only viable in niche, infrastructure-heavy deployments and are not general solutions. The VitalTrack PPG&Motion sensor pod, which physically resembles the target pod, remains "coming soon" on Crowd Supply with unverified openness. The Aidlab "Hackable Wearable" is a chest-strap platform, not a wrist device. Watchy has no PPG sensor. New entries like SensWear and Biocoin are announced as open-source platforms, but confidence is unverified from secondary reporting; they are worth watching but not yet tangible.

The biggest changes in this window are the maturation of more capable open devices and new software tools. The HealthyPi Move has successfully funded and begun shipping, offering a major leap in onboard sensing (continuous ECG, SpO2, EDA) in a fully open watch form factor. Its recent firmware update (vendor-claim) adds features, suggesting active development. PineTime is back in stock, and a "Pro" model with more sensors has been announced (secondary), though it remains an upcoming product. On the software side, the open-source Pulse-PPG Foundation Model (unverified) represents a potential leap in signal processing if it delivers on its promise of field-trained PPG analysis. Meshtastic now formally documents a telemetry module for health metrics, though using it requires custom firmware compilation.

The open gaps are clear. There is still no buyable, open, slim wrist pod (PPG, accelerometer, ambient light) with a single stable hardware revision. The component path—pairing an ESP32-S3-MINI-1 module with a MAX30102 and a proper BMS like the M5StampS3 BAT Module—remains a custom PCB project. For someone deciding where to spend attention: if you need a working device today, buy a Bangle.js 2. If you need advanced biometrics in an open package, the HealthyPi Move is now a shipping option. If you are scoping a custom build, the component ecosystem is stable, but the integration work is yours.

Written 2026-08-10 from the changelog below, not from a fresh search.

How the field breaks down, by what we're actually tracking:

• open-firmware-device — 7 items: Bangle.js 2, PineTime, Watchy, HealthyPi Move, Open-SmartWatch, AsteroidOS, H-Watch.
• dev-platform — 5 items: VitalTrack PPG&Motion, Aidlab "Hackable Wearable", SensWear, Biocoin, HealthyPi 6.
• connectivity — 5 items: BLE-to-phone relay (connectivity), LoRaWAN (connectivity), Meshtastic (connectivity), ESP-NOW / ESP-to-ESP (connectivity), Cellular/LTE direct-on-wrist relay.
• component — 4 items: ProtoCentral Pulse+, MAX30102 bare breakout modules, M5StampS3 BAT Module, ESP32-S3-MINI-1 (chip-down module).
• protocol — 1 item: Pulse-PPG Foundation Model.

Gone quiet or discontinued. Kept here rather than deleted, because a tracker that removes its failures is a product page:

• Cellular/LTE direct-on-wrist relay — Putting an LTE modem (e.g. SIM7080G class) directly on the wrist device instead of relaying through a phone. Last activity 2026-08-04.

Tracked products

Available now. Price and regulatory status are blank where we have not read them on a primary source — they are never inferred.

Our take

The rest of this page is machine-written. These lines are not.

Bangle.js 2. The strongest shipping precedent for this build. No ambient-light sensor — the one gap versus the target spec. Recommended as the fastest way to validate the wrist-telemetry concept before committing to a custom PCB.

Watchy. Open hardware reference, not a sensing candidate — no HR path.

HealthyPi Move. Most fully-featured open sensing platform found, but a chunky research watch — the opposite of the slim target form factor. Reference for sensor selection, not for mechanical design.

Aidlab "Hackable Wearable". Open-ish and real, but chest-worn and ~4x the target BOM budget for the whole custom band. Reference only.

ProtoCentral Pulse+. Breadboard-stage part for proving the PPG signal chain pre-PCB.

MAX30102 bare breakout modules. Cheapest way to start the custom-board PPG signal chain this week.

M5StampS3 BAT Module. Established during the 2026-08-04 cart audit: no Stamp-line part combines BMS + motion, which is what pushed this project into custom-PCB territory.

ESP32-S3-MINI-1 (chip-down module). Fallback if the design ever needs WiFi/ESP-NOW instead of nRF52 BLE — note this trades away the lower-power nRF52 baseline chosen for the slim band.

Upcoming

Announced, no date.

PineTime

Pine64's fully open smartwatch: nRF52832, heart rate + accelerometer, community-built InfiniTime firmware, dev edition with SWD access.

First seen 2026-08-04 · confidence primary-source · open-firmware-device

Why it's here: PineTime Pro specifications detailed: AMOLED, GPS, dual-core Cortex-M33. (2026-08-31) — Liliputing article details expected PineTime Pro upgrades including AMOLED display, GPS, blood oxygen sensor, digital crown, and dual-core Cortex-M33 MCU.

Sources: Pine64 product page

Our take. Cheapest genuinely-open option. Same nRF52 lineage as the target custom-PCB MCU choice.

Coming Soon

Announced with a date, or an open pre-order.

VitalTrack PPG&Motion

Newert (Korea) sensor pod: synchronized PPG + IMU streamed over BLE, 14.5 x 40.5 x 12 mm, ~3 g. Crowd Supply campaign listed "coming soon." 3D-printable enclosure files and iOS/Android/Windows SDK, pitched as an open development platform.

First seen 2026-08-04 · confidence secondary · dev-platform

Why it's here: No changelog entry explains this status yet.

Sources: Crowd Supply · Newert product page

Our take. Closest thing found to a buyable version of the target pod — pod-in-capsule sized already. Open DATA access confirmed (SDK, enclosure files); open FIRMWARE is not yet confirmed — watch the campaign page. No ambient-light sensor. Not yet funded.

HealthyPi 6

ProtoCentral's latest open-source biometric monitor platform based on STM32H7 dual-core microcontroller.

First seen 2026-08-18 · confidence unverified · dev-platform

Why it's here: HealthyPi 6 Crowd Supply campaign page is live with expansion modules. (2026-08-31) — ProtoCentral's HealthyPi 6 open-source biometric monitor platform is listed on Crowd Supply, alongside AI accelerator (HealthyLink Edge AI) and EEG expansion modules.

Sources: Crowd Supply page

What We're Watching

Exists, unproven, or newly discovered. This is where auto-discovered items land.

LoRaWAN (connectivity)

Long-range, low-power LoRa with a managed network layer. Needs gateway infrastructure (own concentrator or public TTN-class coverage) not currently present in the estate.

First seen 2026-08-04 · confidence primary-source · connectivity

Why it's here: No changelog entry explains this status yet.

Sources: none recorded — this item is a name we've seen and not much more.

Our take. Wrong tool for a wrist device that mainly stays in range of home BLE infrastructure — kilometers of range and low bandwidth solve a problem this project doesn't have.

Meshtastic (connectivity)

Open-source LoRa mesh firmware, no gateway/carrier required, active real project (Heltec/T-Beam/RAK hardware).

First seen 2026-08-04 · confidence primary-source · connectivity

Why it's here: Meshtastic documentation details telemetry module supporting health metrics. (2026-08-10) — Meshtastic's telemetry module configuration documentation lists support for health metrics (heart rate, oxygen saturation, body temperature), requiring firmware compiled with specific macros.

Sources: Meshtastic

Our take. Genuinely real and solves the gateway problem LoRaWAN has, but not the radio-on-the-wrist size/bandwidth problem — a LoRa radio doesn't fit the slim pod, and Meshtastic is built for short text/telemetry, not continuous biometric streaming. More relevant to a sibling away-node project than the band itself.

ESP-NOW / ESP-to-ESP (connectivity)

Espressif's proprietary WiFi-band peer-to-peer protocol (used by Stamp Fly to Atom Joystick) — direct device-to-device, no AP needed.

First seen 2026-08-04 · confidence primary-source · connectivity

Why it's here: No changelog entry explains this status yet.

Sources: none recorded — this item is a name we've seen and not much more.

Our take. Only runs on ESP32-family silicon, not the nRF52 chosen for the slim band's lower power draw. Adopting it means swapping the MCU family and giving back the power/size advantage that made the band slim in the first place. Not adopted.

SensWear

Open-source modular wearable development platform based on Nordic nRF54L15 Bluetooth LE SoC and multiple sensors.

First seen 2026-08-10 · confidence unverified · dev-platform

Why it's here: SensWear project page on Hackaday.io confirms design files to be published on EasyEDA. (2026-08-18) — The SensWear project creator stated on the Hackaday.io project page that they are working on publishing the design files on EasyEDA for ease of use.

Sources: CNX Software Article · Hackaday.io Project

Biocoin

Open-source wearable platform for multiplexed and multimodal biosensing, published in an academic journal.

First seen 2026-08-10 · confidence unverified · dev-platform

Why it's here: No changelog entry explains this status yet.

Sources: npj Biosensing Article

Pulse-PPG Foundation Model

Open-source, field-trained foundation model for processing photoplethysmography (PPG) signals from wearables.

First seen 2026-08-10 · confidence unverified · protocol

Why it's here: No changelog entry explains this status yet.

Sources: arXiv Paper

Open-SmartWatch

Open-source smartwatch project with published hardware files, firmware, and 3D-printable enclosure designs.

First seen 2026-08-24 · confidence unverified · open-firmware-device

Why it's here: Open-SmartWatch project details published hardware files, firmware, and 3D-printable designs. (2026-08-31) — The Open-SmartWatch project page confirms availability of hardware files for ordering PCBs or assembled watches, firmware source code, and 3D-printable enclosure designs.

Sources: Project homepage

AsteroidOS

Open-source Linux distribution for smartwatches, allowing users to revive or customize supported devices.

First seen 2026-08-24 · confidence unverified · open-firmware-device

Why it's here: AsteroidOS 2.0 community-driven Linux distribution for smartwatches launches. (2026-08-31) — AsteroidOS 2.0 is released as an open-source Linux distribution for smartwatches, aiming to give users control over firmware and data on supported devices.

Sources: Project homepage

H-Watch

Fully open-source smart monitoring platform for health tracking with NB-IoT cellular connectivity.

First seen 2026-08-31 · confidence unverified · open-firmware-device

Why it's here: H-Watch open-source smart monitoring platform with NB-IoT cellular connectivity announced. (2026-08-31) — ETH-PBL publishes H-Watch, a fully open-source wearable smart monitoring platform for health tracking featuring NB-IoT for direct cloud connectivity and reported low power consumption.

Sources: GitHub Repository

Promising

Early-stage, but the evidence or the approach is genuinely interesting. The only editorial bucket on this page — an item only lands here with a reason recorded in the changelog.

BLE-to-phone relay (connectivity)

Band stays BLE-only; a phone companion app holds the connection and forwards telemetry over whatever WAN the phone already has. The standard pattern (Whoop/Oura/Garmin/Bangle.js).

First seen 2026-08-04 · confidence primary-source · connectivity

Why it's here: No changelog entry explains this status yet.

Sources: none recorded — this item is a name we've seen and not much more.

Our take. Chosen baseline for the slim band. No size or battery penalty on the wrist device; works anywhere the phone has signal, including travel (train/car) since phone stays within a meter.

Open questions

Publishing what we don't know is the point. These are things the job is actively watching for; when one gets answered it becomes a changelog entry and moves down here to the answered list.

• Does VitalTrack PPG&Motion's campaign confirm open FIRMWARE (not just open data access/SDK), and does the Crowd Supply campaign fund? — open since 2026-08-04.
• Has any shipping open-firmware wearable added an ambient-light sensor to a PPG + accelerometer + BLE combo, or is that combination still custom-PCB-only? — open since 2026-08-04.
• Has any Colmi/consumer-ring-class device stabilized on one hardware revision long enough for community firmware to be reliably reusable across purchases? — open since 2026-08-04.
• If a Meshtastic mesh backbone is ever built for the away-node project, would it change the calculus for band connectivity while traveling? — open since 2026-08-04.

Full changelog

Everything, newest first, grouped by the month we found it. Long by design — it's the receipts.

August 2026

Dreamlab Live Research uses autonomous systems to track the state of the art in fields of interest. New trackers appear as the interests do.

Generated from a versioned dataset in a git repository: every state this page has ever been in is a commit, and a bad run is revertible. The dataset is the source; this page is build output and is not itself edited.

• Dataset: data/live-research/open-wearables.json (schema version 2)
• Runs completed: 8 · cadence: weekly
• Items tracked: 22 · changelog entries: 18
• Distinct sources seen: 222
• Last run recorded: 2026-09-21T05:47:15Z (status: no-changes)