Use 2.4 GHz Wi-Fi. If your router combines 2.4 GHz and 5 GHz under one name, the sensor still needs the 2.4 GHz network to be available.
Check name and password length. SSIDs must be 32 characters or fewer. Passwords must be 63 characters or fewer.
Use the app first. The app sends Wi-Fi details to the device over the paired Bluetooth connection.
Use the captive portal if needed. When no Wi-Fi is saved, the device can expose a temporary Terrestream-XXXX setup network. Join it from your phone, open 192.168.4.1, and enter Wi-Fi details there. The portal times out after 10 minutes idle.
If it still fails. Move the sensor closer to the router, confirm the password, avoid guest networks that block devices from the internet, and retry setup.
