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

# Firmware upgrades

> How to update Delta GaN ESC firmware safely, including version pairing with VESC Tool and recovering from a failed update.

How to move a Delta GaN ESC to a new firmware build without losing your configuration or bricking the board.

<Warning>
  **Never disconnect or cut power during a firmware update.** An interrupted write can leave the controller unable to boot. Make sure the DC supply is stable and the USB cable will not be knocked out before you start.
</Warning>

## Before you start

<Steps>
  <Step title="Back up your configuration">
    In VESC Tool, save both configurations to XML:

    * **XML → Save Motor Configuration**
    * **XML → Save App Configuration**

    An upgrade can reset parameters to defaults. Restoring a saved XML takes seconds; re-deriving a tuned configuration does not.
  </Step>

  <Step title="Note your current versions">
    The status bar shows the connected hardware and firmware version. Write down what you are coming *from*, so you can go back if the new build misbehaves.
  </Step>

  <Step title="Check VESC Tool version pairing">
    If Intrusive Robotics has specified a VESC Tool version for the target firmware, **use that version**. Mismatched tool and firmware versions can produce misread parameters or a failed update.
  </Step>

  <Step title="Power the board properly">
    DC power on the main input terminals, then USB A → USB C. The Delta is not powered over USB and will not enumerate on USB alone.
  </Step>
</Steps>

## Where to get firmware

<Card title="Latest release" icon="download" href="https://github.com/IntrusiveRobotics/Delta/releases/latest">
  Prebuilt Delta firmware binaries on GitHub.
</Card>

VESC Tool also ships bundled firmware. On a firmware mismatch warning, the bundled build matching your hardware is usually the right choice.

## Performing the update

<Steps>
  <Step title="Connect">
    Serial interface, correct port, click Connect. Confirm the status bar shows the board.
  </Step>

  <Step title="Open the Firmware page">
    In VESC Tool's left toolbar.
  </Step>

  <Step title="Select the firmware">
    Either the bundled build matching your hardware, or a `.bin` you downloaded. **Confirm it is the Delta build** — flashing firmware for different hardware is how boards get bricked.
  </Step>

  <Step title="Flash and wait">
    Start the update and leave it alone. Do not unplug USB, cut DC power, or close VESC Tool. The controller reboots on its own when finished.
  </Step>

  <Step title="Reconnect and verify">
    Reconnect and confirm the status bar reports the new firmware version.
  </Step>
</Steps>

## After the update

<Steps>
  <Step title="Check your parameters survived">
    Read the motor and app configurations back and compare against your saved XML. Pay particular attention to current limits, voltage cutoffs, and temperature limits.
  </Step>

  <Step title="Restore from XML if needed">
    **XML → Load Motor Configuration**, then write it to the controller.
  </Step>

  <Step title="Re-verify before loading the motor">
    Open Realtime Data, run the motor up gently, and confirm the Fault field stays clear — exactly as you would after first setup. See [motor tuning](/guides/motor-tuning).
  </Step>
</Steps>

<Note>
  A major firmware change can alter how detected motor parameters are interpreted. If low-speed behaviour changes after an upgrade, re-run detection rather than assuming the old values still apply.
</Note>

## Troubleshooting

| Symptom                                   | Check                                                                                                    |
| ----------------------------------------- | -------------------------------------------------------------------------------------------------------- |
| Firmware mismatch warning on connect      | Expected when tool and firmware differ. Flash the bundled firmware matching your hardware.               |
| Update fails partway                      | Cable quality and USB hub power. Use a direct port, USB A → USB C, and retry.                            |
| Board will not connect after an update    | Confirm DC power is applied. Try a different cable and port before assuming the worst.                   |
| Parameters look wrong after upgrading     | Tool/firmware version mismatch can misread parameters. Match versions, then restore from your saved XML. |
| Motor behaves differently after upgrading | Re-run detection and re-check limits before applying load.                                               |

## Related

<CardGroup cols={2}>
  <Card title="Experimental firmware" icon="flask" href="/firmware/experimental">
    Pre-release builds and what to expect from them.
  </Card>

  <Card title="Motor tuning and parameters" icon="sliders" href="/guides/motor-tuning">
    Re-verifying limits after an upgrade.
  </Card>
</CardGroup>