Flash Bruce firmware on the M5Stack Cardputer
Install the open-source Bruce firmware on your M5Stack Cardputer directly from this page — nothing to download or install. You need Chrome or Edge on a desktop computer and a USB-C data cable.
How do I flash Bruce on a Cardputer?
Connect the Cardputer with a USB-C cable, click Connect above, choose the serial port, then click Flash. The Cardputer uses an ESP32-S3 and enters flash mode automatically — you do not need to hold any buttons.
Which browsers can flash the Cardputer?
| Browser | Supported |
|---|---|
| Chrome / Edge (desktop) | ✅ Yes |
| Chrome (Android) | ✅ Yes |
| Safari (macOS / iOS) | ❌ No |
| Firefox | ❌ No |
Browser flashing relies on the Web Serial API, which ships only in Chromium-based browsers.
Troubleshooting
| Symptom | Fix |
|---|---|
| No port shows in the picker | Use a USB-C data cable (not charge-only) and try a different port. |
| "Failed to connect" | Unplug and replug the device, then click Connect again. |
| Download / CORS error | The firmware host is briefly unreachable — wait and retry. |
| Wrong chip detected | Make sure no other app (Arduino IDE, serial monitor) holds the port. |
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.
WARNING
For educational and lawful testing purposes only. Comply with all applicable laws in your jurisdiction.