Flash your EucBuddy firmware.
Choose your device and release, then update over USB. Your licence is checked automatically and your settings stay with you.
Ready to update?
Plug in a USB data cable. We'll check your device licence before flashing.
Need help connecting your device?
Use a USB-C data cable — charge-only cables won't work. The steps below follow the board you picked above.
LilyGO T-Display-S3
New device first time
-
Connect the device to your computer by USB-C.
-
Hold BOOT, press and release RESET, then release BOOT. The screen stays dark — that is update mode.
Both buttons sit next to the USB-C port. Access depends on your case. -
Click Update Your Buddy and select USB JTAG/Serial debug unit.
-
Keep USB connected until the update reaches 100% and EucBuddy starts. If the screen stays dark, press either side button once.
Updating EucBuddy
-
Wake the device — press either side button if the screen is dark.
-
Connect it to your computer by USB-C.
-
Click Update Your Buddy and select USB JTAG/Serial debug unit.
-
Keep USB connected until the update reaches 100% and EucBuddy starts. If the screen stays dark, press either side button once.
No port listed? Hold BOOT, press and release RESET, release BOOT and retry. If prompted, follow Licence activation — once per device.
M5Stick-S3
New stick first time
-
Connect the stick to your computer by USB-C.
-
Hold POWER until the screen goes dark and the green LED blinks. Release the button.
Works with the stick on or off. -
Click Update Your Buddy and select USB JTAG/Serial debug unit.
-
Keep USB connected until the update reaches 100% and EucBuddy starts. If the screen stays black, press POWER once.
Updating EucBuddy
-
Turn on the stick.
-
Connect it to your computer by USB-C.
-
Click Update Your Buddy and select USB JTAG/Serial debug unit.
-
Keep USB connected until the update reaches 100% and EucBuddy starts. If the screen stays black, press POWER once.
No port listed? Hold POWER until the green LED blinks, release it and retry. If prompted, follow Licence activation — once per device.
More about Stable and Development
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 device and lets it flash the latest firmware. Once a device is activated, it stays activated — flash as many updates as you want, forever.
-
Start the update with the procedure above. When the flasher reads an unlicensed device, a friendly popup appears: Your EucBuddy needs some care.
-
Click Get your licence to grab a one-time code from Buy Me a Coffee. The code arrives by email.
-
Back on the flasher page, click Already have a licence, then enter your code (
XXXX-XXXX-XXXX-XXXX) and a nickname for your device. -
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 an unused code? Reach out and we'll help you recover it. Each code activates exactly one device and can't be reused on another.