Troubleshooting
Flashing
| Problem | Fix |
|---|---|
| ST-LINK not recognised | Use the Nucleo's ST-LINK USB port and a Micro-USB data cable. Install or update the ST-LINK driver. |
| Can't connect in STM32CubeProgrammer | Set the port to SWD and the programmer to ST-LINK, then click Connect. Unplug and replug the board. |
| FUS version is not v1.2.0.0 or v1.3.0.0 | Update the FUS first with the FUS file from STMicroelectronics for your STM32WB, then install the stack. |
| Stack upgrade fails | Check the file is stm32wb5x_BLE_Stack_full_fw.bin and the address is exactly 0x080CE000. |
| Board doesn't advertise after flashing | Upload both the stack and Micro_BCI.hex, then unplug and power the board again. |
Bluetooth connection
| Problem | Fix |
|---|---|
| Python GUI can't connect | The GUI scripts use a fixed address. Set address to your board's address. See Find your board's address. |
| Device not found in a scan | Check the board is powered and the stack and firmware are installed. Move closer. |
| macOS: address format | bleak on macOS shows a UUID instead of a MAC address. Use the UUID in the script. |
| Found but won't connect | It may already be connected to another app or phone. Close it, power the board off and on, and retry. |
| No Bluetooth option in the browser | Use Chrome or Edge. Safari, Firefox and iPhone / iPad browsers don't support Web Bluetooth. |
Data and signal
| Problem | Fix |
|---|---|
| No data, or all values constant | The shield may be shifted by one pin. Unplug, re-seat it, and check the alignment against the photo. |
| All channels noisy at once | Check the reference and bias ear clips first. Clean the earlobes and clip them firmly. |
| One channel flat or very large | That electrode isn't touching the skin. Part the hair, press it in, or add gel. |
| Strong 50/60 Hz hum | The board must run from the power bank, not a computer's USB port. Move away from chargers. |
| Values in the thousands of µV | Normal DC offset in raw data. Use 1.1_GUI.py (1–40 Hz filter) or filter the data. |
| Big swings when moving | Movement of electrodes or cables. Sit still and keep cables short. |
See Noise elimination for a step-by-step way to find the source of noise.
Still stuck?
Ask on Discord (opens in a new tab), open an issue on GitHub (opens in a new tab), or email pieeg@pieeg.com.