Back to Standard Update

μCritter Bootloader Update

Advanced recovery page for the bootloader firmware only. Use this page only if the uCritter team told you to.

Advanced Users Only. This flow updates the bootloader itself. Most users should return to the standard update page instead.

Note: Chrome or another Chromium browser is required. WebUSB is not supported on iPhone or iPad.

Bootloader Update

Use this only when instructed. The standard update flow now lives on its own page so it stays isolated from this recovery path.

Bootloader Update Progress
Waiting...

Step 1: Flash Bootloader Firmware

This special firmware packages the bootloader update image. Put your Critter into bootloader mode first, then flash this stage.

Loading firmware...

Step 2: Update Bootloader on Device

After the device reboots from Step 1, use the on-device menu:

Settings > DEVELOPER > UPDATE BOOTLOADER

Confirm the update on the device itself and wait for the reboot to finish.

Step 3: Flash Standard Firmware

This returns the device to the normal firmware. If supported, this page will try the USB serial bootloader trigger for you first.

Waiting for Step 2...

Before You Start

Keep this simple: this page is only for the bootloader wizard. If you just need the latest normal firmware, go back to the standard update page.

  • Enter bootloader mode manually with Start + Select + Down, then press reset with a paperclip.
  • Confirm the bootloader screen shows ~CAT BOOTLOADER MODE~ before Step 1.
  • Leave the device plugged in whenever the page is actively guiding you through a flash stage.

Step 1 Notes

Step 1 flashes a temporary firmware image that carries the new bootloader update package.

  • If the browser prompts for permission, choose MCUBOOT.
  • If the device shows up as CAT PROTOTYPE, you are not in bootloader mode yet.
  • If the page asks for a refresh between stages, refresh and stay on this same bootloader page.

Step 2 Notes

The actual bootloader upgrade happens on the device after Step 1 finishes.

  • Navigate to Settings > DEVELOPER > UPDATE BOOTLOADER.
  • Wait for the update and reboot to finish before clicking the Step 2 confirmation button on this page.
  • If the device stalls or reboots oddly, do not continue into Step 3 until the device is stable again.

Step 3 Notes

Step 3 restores the normal application firmware after the new bootloader is in place.

  • The page will try the USB serial bootloader handoff first when supported.
  • If that handoff fails, manually re-enter bootloader mode and click the same Step 3 button again.
  • When Step 3 completes, you can set the device clock from the same page.