Flash your EucBuddy firmware.
Stable: Loading…
Development: Loading…
Firmware update for your M5Stick-S3, directly from the browser. No toolchain, no drivers.
Select your buddy's new home
More boards coming soon.
Stable is recommended for everyday use.
Flashing Instruction
Pick the path that matches your device.
Brand new stick first time
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Connect the device to your computer with a USB-C cable.
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Hold the POWER button until the screen turns off and the green LED starts blinking.
It doesn't matter whether the device is on or off — holding POWER always lands you in bootloader mode. -
Click Update Your Buddy and pick the serial port in the browser dialog. Look for USB JTAG/Serial debug unit.
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Wait for the progress bar to reach 100%. The device should reboot on its own and start EucBuddy. If the screen stays black, press POWER once.
Already flashed with EucBuddy
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Make sure the stick is turned on.
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Connect it to your computer with a USB-C cable.
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Click Update Your Buddy and pick the serial port in the browser dialog. Look for USB JTAG/Serial debug unit.
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Wait for the progress bar to reach 100%. The device reboots on its own and starts EucBuddy. If the screen stays black, press POWER once.
If no serial port shows up in the browser, use the brand-new-stick procedure on the left (just hold POWER until the green LED blinks). If a licence needed popup appears after the flash, see Licence activation below — you only need to do it once per device.
Which firmware should I choose?
Both channels are official EucBuddy builds. Choose the balance that suits you.
Stable
The most thoroughly tested release, chosen to keep everyday rides dependable and avoid breaking changes. This is the best choice for most riders.
RecommendedDevelopment
The newest EucBuddy experience, with cutting-edge features and recent improvements first. It may also contain more bugs or behavior that is still being refined.
Early accessLicence activation
A one-time unlock per device. No subscriptions, no recurring fees.
EucBuddy is a passion project. A single, one-off licence permanently unlocks a stick and lets it flash the latest firmware. Once a device is activated, it stays activated — flash as many updates as you want, forever.
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Flash your stick with the procedure above. When the flasher reads an unlicensed device, a friendly popup appears: Your EucBuddy needs some care.
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Click Get your licence to grab a one-time code from Buy Me a Coffee. The code arrives by email.
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Back on the flasher page, click Already have a licence, then enter your code (
XXXX-XXXX-XXXX-XXXX) and a nickname for your stick. -
Click Activate licence. Done — the device is now permanently unlocked and the firmware finishes flashing. Re-flash anytime with the procedure above; you'll never be asked again.
Lost your code or changed sticks? Reach out — codes are one-device-one-purchase, but we can help. Each code adds exactly one device and can't be reused.