Troubleshooting
Browser and connection
| Problem | Fix |
|---|---|
| The lab won't connect at all | Use desktop Chrome or Edge, on the HTTPS site. Safari, Firefox and phones are not supported. |
| No serial port appears | Use a USB data cable, not a charge-only one. Close the Arduino IDE and any other serial monitor. |
| Starter kit numbers don't move | When the port opens the kit restarts. Wait until its status says live. |
Octopus-16-XXXX not in the Bluetooth list | Check the power bank is on and the LED blinks slowly (advertising). Move closer to the computer. |
| Octopus connects, then drops | Retry the connection. Keep the board close to the computer for the first run. |
Flashing
| Problem | Fix |
|---|---|
| XIAO port not found | Hold BOOT, tap RESET, release BOOT, then install again. |
| Octopus silent after flashing | Unplug and replug the USB once. |
| Starter kit flash fails | Close other serial monitors. Only Uno / ATmega328P boards (16U2 or CH340) are supported. |
| Kit screen doesn't say "octoBio Kit Ready" | Flash again from the Flash page. |
Signal
| Problem | Fix |
|---|---|
| Octopus on Bluetooth but no EEG data, or LED fast double-blinks | The XIAO is seated the wrong way round (180°). Reseat it so the 5V / GND / 3V3 labels line up. A board that flashes and shows up on Bluetooth does not prove the ADC is connected. |
| EEG ok stays red | Press the board straight down so every pin touches the scalp. Part the hair under the pins. Sit still. |
| Huge swings in the signal | Blinks, jaw clenches and movement. Relax the face and keep still. |
| Alpha doesn't rise with eyes closed | Place the board over the back of the head (visual cortex). Keep the eyes closed for a full 10 seconds. |
| Distance shows a negative number | The echo was missed. Point the sensor at a facing surface. |
Pogo pin care
The Octopus 16 uses spring-loaded pogo pins. Dirt, liquid or sideways force can make a pin stick.
- Clean the pin tips with isopropyl alcohol (IPA above 90%) and blow out dust with compressed air.
- Press the board straight down (90°). Never push or tilt the pins sideways under pressure.
- To free a stuck pin: put a drop of IPA into the pin barrel, gently work the plunger with a non-metal tool, and let it dry fully before powering on.
🚫
Do not use oil or grease on the pins. It attracts dirt and damages conductivity.
See also Octopus 16 pogo pin care.
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.