Troubleshooting
Uploading the sketch
| Problem | Fix |
|---|---|
| Board not listed in the Arduino IDE | Install Arduino UNO R4 Boards in Tools → Board → Boards Manager. Use a USB-C data cable. |
WiFi.h errors | Choose the board Arduino UNO R4 WiFi, not the Minima. |
| Upload fails | Unplug the power bank, use only the computer's USB while uploading. Try another USB-C cable. |
Wi-Fi and data
| Problem | Fix |
|---|---|
| Python shows nothing | Check the IP address is the same in the sketch (udp.beginPacket) and in Python (UDP_IP), and that it's your computer's current IP. Computers can get a new IP after a restart. |
| Arduino doesn't join the network | Check the Wi-Fi name and password in the sketch. Use a 2.4 GHz network. |
| Computer and Arduino on different networks | Both must be on the same Wi-Fi network. Guest networks often block devices from talking to each other. |
| Firewall blocks the data | Allow Python through the firewall for UDP port 13900, or test with the firewall off briefly. |
Address already in use in Python | Another program uses port 13900. Close it, or check with netstat -ano | findstr :13900 on Windows. |
| Data slow or with gaps | Run speed_test_250_samples.py. Move the Arduino closer to the router and away from other 2.4 GHz devices. |
Signal
| Problem | Fix |
|---|---|
| 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 Arduino must run from the power bank, not the computer's USB. Move away from chargers and power strips. |
| Can't see blinks or chewing | The default view is the 8–12 Hz alpha band. Change the filter to 1–40 Hz (see Software). |
| Big swings when moving | Movement of the electrodes or cables. Sit still, keep cables short. |
| Alpha doesn't rise with eyes closed | Check an electrode is on the back of the head (Pz, O1, O2), keep the eyes closed for 10 seconds in a quiet room. |
Is it the board or the setup? Set all channels to input-shorted (CHnSET = 0x01) in the sketch. If the signal stays within a few µV, the hardware is fine. See Noise elimination.
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.