← Back to all work
Beta testing · Consumer electronics

EWatch, a programmable ESP32-S3 smartwatch.

EWatch is a programmable ESP32-S3 smartwatch and dev board. Code it by hand like any other Arduino board, or describe what you want and let an LLM write the firmware. You can buy it as a bare board, as a kit to build yourself, or ready to wear. I design and assemble them here in the UK.

EWatch is in certification and has not shipped yet.

It has WiFi, Bluetooth and a lithium battery, so it has to pass radio, EMC, electrical safety and product security assessment before I am allowed to send one to anyone. Pre-orders and Kickstarter pledges pay for that testing. Nothing ships until it passes. Estimated delivery: April 2027.

How certification is going →

Pre-order ↗ Specifications
Fully assembled EWatch smartwatch on a black mesh strap

EWatch

In the press

Written about EWatch.

Sht 02 — Three ways in

Same board in all three.

The EWatch bare board: the assembled ESP32-S3 circuit board with its USB-C port
SKU · EW-PCB-01Bare board

The PCB

Just the board and the screen: ESP32-S3, USB-C, display connector, assembled and bring-up tested. Bring your own battery, strap and enclosure.

  • EWatch mainboard (assembled)
  • 1.69" touch display
£59 Pre-order

Pre-order. Ships after certification, estimated April 2027. Cancel any time before it ships for a full refund. Pre-order terms

Most popular
The EWatch kit laid out: circuit board, touchscreen, battery, vibration motor and mesh strap
SKU · EW-KIT-01Self-assembly

The Kit

Every part of the watch, laid out for a one-afternoon build. PCB, screen, battery, vibration motor and strap, plus the case CAD files so you can print it, mill it or send it out.

  • EWatch mainboard
  • 1.69" touch display
  • 400 mAh battery
  • Vibration motor
  • Strap
  • Case CAD files (On request)
£99 Pre-order

Pre-order. Ships after certification, estimated April 2027. Cancel any time before it ships for a full refund. Pre-order terms

The fully assembled EWatch on a black mesh strap
SKU · EW-ASM-01Ready to wear

The Watch

Assembled, tested and pre-flashed. Charge it and start writing watch faces.

  • Fully assembled EWatch
  • Free USB-C programming cable
  • Pre-flashed with latest EWatchOS
£129 Pre-order

Pre-order. Ships after certification, estimated April 2027. Cancel any time before it ships for a full refund. Pre-order terms

EWatch (models EW-PCB-01, EW-KIT-01, EW-ASM-01) will receive security updates until at least 31 December 2029. Security and support

Certification

Certification status

What EWatch has to pass before it ships: radio (EN 300 328), EMC (EN 301 489), electrical safety (EN 62368-1), RF exposure, and the UK product security rules for connected devices. The battery has to come with UN38.3 transport test evidence.

Sht 03 — How it scales

As deep as you want to go.

EWatch is a full ESP32-S3 development board, wrist-sized. Write the firmware yourself, the way you would on a Feather or a Watchy. Or paste the open-source drivers and one example project into an LLM and let it write the firmware for you.

If you'd rather not install anything, write and compile at ewatch.cloud and flash the watch from Chrome over USB-C. The editor, flashing and the project library are free.

i.

Open-source drivers

Drivers for display, touch, IMU, BLE, charging and sleep modes. Call display.text(), imu.steps(), ble.notify(). Everything's on GitHub.

ii.

Reference watch faces

Working watch faces you can browse and fork in EWatch Cloud. Read one, change it, flash your version. They also make good context to hand an LLM, because the code already runs.

iii.

Vibe-code with an LLM

I run Claude Code inside PlatformIO with the driver headers and one example pasted in as context. Ask for a watch face that shows your next meeting and vibrates 5 minutes before: it usually works first try, because the model has real running code to copy from. When it doesn't, you end up reading the driver yourself.

iv.

Standard ESP32-S3 board

Underneath it's a vanilla ESP32-S3 dev board. Program it from Arduino IDE, PlatformIO, or ESP-IDF in C, C++, MicroPython or Rust.

v.

Drop to the metal

Drive peripherals over I²C / UART, write to registers, fold it into your own RTOS task graph. The drivers are open source, so when you outgrow them you can read them.

vi.

From hobby to product

Start with the LLM. Drop to the driver layer when you need precision, or to bare-metal when you're counting microamps.

Sht 04 — Specifications

Hardware, documented.

Display1.69″ full-colour touchscreen
ProcessorESP32-S3 · WiFi + Bluetooth Low Energy
Battery400 mAh · runtime depends on how much time you spend in sleep and deep sleep
ConnectivityUSB-C · WiFi · Bluetooth · I²C · UART
ChargingCharging, battery-level sensing, latching power button
Programmable inC, C++, Python via Arduino IDE, PlatformIO or ESP-IDF
Water resistanceNone. Keep it dry.
Security updatesUntil at least 31 December 2029
StrapStandard 20 mm · included on Kit & Watch · user-replaceable
Board dimensions34 × 28 mm · 2-layer · ENIG finish
Reviews

In their own words.

5.0 / 5 From 1 review How reviews work
  1. Beta tester · early unit

    Fantastic little device!

    Got my unit of Ewan a couple months back, and it's been amazing to see the development that's been happening with it. There is something about having a platform that's so accessible and customisable on your wrist that is really exciting. Especially with options for vibe coding things, and how well it's set up for it. I've found some improvements I want to make to the casing, and was even considering using this as a platform / start for a little desk robot which would be so cute! I know there is no way I would have the time to get to making something like this where I can tinker with it, so having this as a starter device is pretty ideal.

    Jamie Hutcheson ·

Sht 07 — Frequently asked questions

Questions about EWatch.

Is EWatch a smartwatch like an Apple Watch or a Garmin?

No. EWatch is a dev board for people who want to program their own watch. It doesn't track health or fitness out of the box. It's a watch you write the software for.

Which version should I pick?

The PCB if you want an ESP32-S3 board with a good touchscreen for your own project. The Kit if you want to build the watch yourself (you'll need a soldering iron for the battery and the vibration motor). The Watch if you want it assembled, tested and flashed, ready to program.

Do I need to install anything to program it?

No. You can write, compile and flash from Chrome at ewatch.cloud over USB-C. If you'd rather work locally, use the Arduino IDE or PlatformIO. ESP-IDF should work too, but I haven't tested it yet.

Do I need to pay for EWatch Cloud?

The editor, flashing and the project library are free. The AI assistant and other compute-heavy tools run on Cloud credits, which you top up when you need them. Early adopters get a month of the paid features free.

Do I have to use the AI assistant?

No, it's optional. You can write everything yourself in C, C++ or MicroPython, or build it from blocks in Studio.

When will I get it?

Estimated April 2027. Before it ships, the watch has to pass UKCA and CE radio certification. If anything moves that date, I'll post an update straight away.

Is it certified?

Not yet. Radio, EMC and safety testing comes before any sales, and nothing ships until it passes.

Is it waterproof?

No. It hasn't been tested for water resistance, so keep it dry.

Can I make my own case?

Yes. The Kit comes with the case CAD files, so you can print or mill your own.

What strap does it use?

The Watch comes on a 20 mm metal mesh strap with a magnetic latch. Any standard 20 mm strap with spring bars fits.

How long does the battery last?

It ships with a 400 mAh battery. These are calculated battery life figures: I worked them out from the component datasheets, because I haven't measured battery life on production units yet. They assume the screen dims to a screensaver after 5 seconds and sleeps after 20.

Calculated battery life:

  • Checking the time and notifications through the day, no WiFi or Bluetooth: about 5 days.
  • The same with WiFi syncing every 5 minutes: about 3 to 4 days.
  • With Bluetooth connected all day: about 7 hours on the current firmware, which keeps the processor at full speed while Bluetooth is on. Improving that is on my list.
  • Screen on the whole time: about 7 hours.

It's a dev board, so your own code decides most of this. I'll post measured figures before the watches ship.

How long does it take to charge?

The calculated charge time is about an hour and a half to two hours from empty over USB-C. I haven't measured it yet.

Prompt it. Wear it.

In certification

EWatch —

Two options. Either is fine.

01

Tell me when I can order

I'll email you news about EWatch and the other things I make. A few a year. Unsubscribe any time. Privacy.