> ## Documentation Index
> Fetch the complete documentation index at: https://docs.meowkit.cc/llms.txt
> Use this file to discover all available pages before exploring further.

# Firmware Update

This guide walks you through your first firmware update. Updating the firmware does not modify files stored on the microSD card.

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# What you need

* A Windows, macOS, or Linux computer
* A USB Type-C Cable
* The latest version of Google Chrome or Microsoft Edge
* A MeowKit with at least 30% battery

> MeowKit has one USB port. File transfer, USB features, and firmware updates all share this port and cannot be used at the same time.

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# Start the update

Before you begin, make sure MeowKit is **powered off** and the USB cable is disconnected.

<Steps>
  <Step title="**Enter Download Mode.**">
    Insert a Dupont jumper wire through the opening on the back of MeowKit until it presses and holds the `BOOT` button.

    Keep holding `BOOT`, then press and hold the Power button for 1–2 seconds. Release the Power button, then release `BOOT` and remove the jumper wire.

    The screen will remain off in Download Mode. This is expected.
  </Step>

  <Step title="**Connect MeowKit.**">
    Use a **USB Type-C cable** to connect Meowkit to your computer.
  </Step>

  <Step title="**Open the download page.**">
    Go to [https://meowkit.cc/pages/download](https://meowkit.cc/pages/download) and click "**Connect and install**".
  </Step>

  <Step title="**Select the serial port.**">
    Choose **USB JTAG/serial debug unit (COMxx)**, such as COM16, then click "**Connect**".

    On Windows, the port name also includes a COM number, such as `COM16`. Port names may appear differently on macOS and Linux.  
  </Step>

  <Step title="**Select the firmware.**">
    Click "**Install Meowkit S3**".
  </Step>

  <Step title="**Confirm the installation.**">
    Check "**Erase device**", then click "**Next**".

    > **Important:** Erasing the device removes settings and data stored in MeowKit’s internal memory. Files on the microSD card are not affected.
  </Step>

  <Step title="**Start the update.**">
    Confirm the installation and click "**Install**" to begin the firmware update.
  </Step>

  <Step title="**Wait for completion.**">
    Keep MeowKit connected while the firmware is being installed. Do not close the browser or disconnect the USB cable.

    When the progress reaches 100% and **Installation complete** appears, the update is finished.
  </Step>
</Steps>

If MeowKit does not restart automatically, disconnect the USB cable and power it on normally.

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# If you do not see a serial port

Try these steps in order:

1. Disconnect the USB cable and power off MeowKit.
2. Connect directly to another USB port on your computer. Do not use a USB hub or dock.
3. Try another USB-C cable that supports data transfer.
4. Enter Download Mode again: hold BOOT, power on MeowKit, wait 2 seconds, release BOOT, then reconnect the USB cable.
5. Close any software that may be using the serial port, such as the PlatformIO Serial Monitor.
6. Reload the download page and click Connect and install again. If the port still does not appear, try another computer.

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# If the update is interrupted

An interrupted installation does not permanently damage MeowKit.

Power off the device, enter Download Mode again, and restart the installation. MeowKit may not start normally until the firmware has been written successfully.

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