The Device Flasher page is where you load the firmware file you built on the configuration page onto your device. This works for both the T-Watch S3 and the T-Embed, using the same page.

This is called ‘flashing’ the device, as the memory that the firmware is written to is called flash memory.

It all happens in your browser — there’s nothing to install. You’ll need Google Chrome or Microsoft Edge; other browsers such as Firefox and Safari can’t talk to the device over USB and won’t work.

You don’t need any programming knowledge — just work through the page from top to bottom.

Before you start

You’ll need:

• The .bin firmware file you downloaded from the T-Watch-S3 configuration page or the T-Embed configuration page.
• A USB cable that carries data, not just power. Some cables only charge — if your device isn’t found in Step 2 below, try a different cable.
  • The T-Watch S3 uses a USB micro cable.
  • The T-Embed uses a USB-C cable.

Step 1 — Select the firmware file

Under 1. Select Firmware File, click the file box and choose the .bin file you downloaded from the configuration page.

The page checks the file and uploads it. You don’t have to set a start address or any other technical option — the file you download already contains everything the device needs, and the page works out where it goes.

If you see an error message here:

• “File must be .bin” — you’ve picked the wrong file, or renamed the firmware so it no longer ends in .bin.
• “File too small” — the file isn’t a firmware image. A real one is at least 0.3 MB. This usually means a download didn’t finish, so download it again from the configuration page.

About the Audio File Status section

Section 2. Audio File Status is there for information only. It lists what it found for both devices, whichever firmware you happen to have selected, so seeing a line about the other device is normal and isn’t a mistake.

You don’t need to do anything in this section. If you chose to have sound on the T-Embed, it is already built into the .bin file — there’s no separate audio file for you to select or flash.

Step 2 — Connect your device

Plug your device into your computer with a data-capable USB cable — micro-USB for the T-Watch S3, USB-C for the T-Embed.

Once the firmware file has been checked, a Connect button will appear under 3. Connect & Flash. Click it. Your browser will show a list of devices — choose the one for your watch or T-Embed and click Connect in that list.

The names in this list come from your computer, not from HandShake, so they’re often unhelpful — something like “USB Serial Device”, “USB JTAG/serial debug unit”, or a string of letters and numbers rather than “T-Watch S3”. If it’s not obvious which entry is your device, close the list, unplug the device, click Connect again and note down what’s in the list without it, then plug the device back in and click Connect once more. The extra entry that appears only when the device is plugged in is the one you want.

If your device doesn’t appear in the list, make sure it’s powered on and properly connected, then try disconnecting and reconnecting the cable.

Step 3 — Install the firmware

Once the device is connected, a small window opens with a few choices. Click Install HandShake code.

You’ll be asked to confirm. There’s also an Erase device tick box — you can leave this alone. The firmware you downloaded is a complete image, so erasing first isn’t needed.

You’ll then see it work through Preparing installation, Writing, and finally Installation complete. Writing takes a short while — leave the cable connected and don’t close the browser tab until it says it has finished.

The device restarts on its own once installation is complete, so there’s nothing further for you to do.

If something goes wrong

Don’t panic. If flashing fails partway through, or you flash the wrong file by mistake, just reconnect the device and repeat the steps above with the correct file. There’s no way to damage the device by flashing it again.

• Device not detected? Check it’s connected and powered on. Try a different USB cable or a different USB port on your computer.
• Flash failed? Disconnect and reconnect the device, then try again.
• Still stuck? Open the browser’s developer console (press F12) to see if there’s an error message, and get in touch if you need help — it’s useful for me to know if you’ve hit a problem.