Flash Bruce firmware on the M5Stack Core2
Install the open-source Bruce firmware on your M5Stack Core2 (ESP32) directly from this page. You need Chrome or Edge on a desktop computer and a USB-C data cable.
How do I flash Bruce on the Core2?
Connect the Core2 with a USB-C cable, click Connect, choose the serial port, then click Flash. The board resets into flash mode automatically via the CH9102 or CP2102 USB bridge.
Which browsers can flash the Core2?
| Browser | Supported |
|---|---|
| Chrome / Edge (desktop) | Yes |
| Chrome (Android) | Yes |
| Safari (macOS / iOS) | No |
| Firefox | No |
Browser flashing relies on the Web Serial API, available only in Chromium-based browsers.
Troubleshooting
| Symptom | Fix |
|---|---|
| No port shows in the picker | Use a USB-C data cable (not charge-only). On Windows, install the CH9102 or CP2102 driver if the port isn't detected. |
| Failed to connect | Unplug and replug the device, then click Connect again. |
| Download / CORS error | The firmware host or proxy is briefly unreachable. Refresh and retry. |
| Board unresponsive after flash | Hold the side button while connecting USB to force bootloader entry, then click Connect. |
What is Bruce?
Bruce is an open-source firmware tool for ESP32 devices used in wireless and hardware research and education. Source code and releases are published at github.com/BruceDevices/firmware under the AGPL-3.0 license.
Frequently asked questions
What is Bruce firmware?
Bruce is an open-source ESP32 multi-tool firmware (Sub-GHz, RF, IR, RFID/NFC, WiFi, BadUSB). It is community firmware (AGPL-3.0); this page flashes the upstream binary.
Does the M5Stack Core2 enter flash mode automatically?
Yes. The Core2 uses a CH9102 or CP2102 USB bridge, which supports automatic bootloader entry via the DTR/RTS lines — just click Connect, no buttons needed.
Do I need an RF module for Bruce on the Core2?
Bruce's Sub-GHz tools need an external CC1101 module and the 2.4 GHz tools need an nRF24 module. The Core2 base unit does not include these radios, so you'll need add-on hardware to use those menus.
Which browsers can flash the Core2?
Chrome or Edge on desktop (and Chrome on Android). Flashing uses the Web Serial API, which Safari and Firefox do not support.
WARNING
For educational and lawful testing purposes only. Comply with all applicable laws in your jurisdiction.