WiFi Logic

This page explains how the device decides between running its own Access Point and connecting to your WiFi network, and how it behaves over time.

Terminology: STA mode (Station) is sometimes also called Client mode. Both terms describe the same role: the device joining your existing WiFi network. AP mode means the device runs its own WiFi Access Point that you connect to directly.

WiFi States

The device can be in one of the following states:

• AP — The device runs its own Access Point. Used when no WiFi client credentials are configured.
• STA_CONNECTING — A short STA-only phase where the device tries to join your WiFi network without exposing its own AP.
• STA — The device is connected to your WiFi network.
• AP_STA — Fallback mode: the device runs its own Access Point and keeps retrying the WiFi client connection in the background.
• OFF — WiFi is fully turned off (to save power).

How It Works

Starting up

• If no WiFi client credentials are configured, the device starts directly in AP mode.
• If WiFi client credentials are configured, the device always starts with a short STA_CONNECTING phase. During this phase it tries to join your network without broadcasting its own AP.
  • If the connection succeeds before the initial timeout expires, the device stays in STA.
  • If the connection does not succeed in time, the device switches to AP_STA.

The length of the initial STA-only window is set by Initial WiFi client connection attempt (seconds) in the configuration.

Fallback (AP_STA)

• In AP_STA, the Access Point becomes available so you can still reach the device, while the STA side keeps trying to connect in the background.
• If STA connects while in AP_STA, the AP is turned off and the device returns to STA.

Losing the connection

• If STA disconnects after being connected, the device does not go straight back to AP. It first starts a new STA_CONNECTING phase.
• This means every new connection attempt starts with a short STA-only window — including boot, retry after OFF, and reconnect after a lost connection.

Turning WiFi off

• In AP mode, the AP can stay available forever, or turn off after the configured AP timeout (Disable Auto AP after (minutes), 0 = stay on).
• In AP_STA mode, WiFi can turn fully OFF after the AP has been idle long enough (Disable AP+Client after (minutes), 0 = never).
• If retry after OFF is enabled (Retry interval after WiFi off (minutes)), the device waits for the configured interval and then restarts the whole cycle from STA_CONNECTING.
• If retry is disabled (0), OFF becomes a terminal state — WiFi stays off until reboot or manual intervention.

Low power mode: In paths where WiFi would normally transition to OFF, the device sends a status packet and restarts instead.

State Transitions

Scenarios

1. No WiFi credentials

• The device starts its AP immediately.
• If AP timeout is disabled, the AP stays up continuously.
• If AP timeout is enabled and nobody uses the AP for long enough, WiFi turns off.

2. WiFi available at boot

• The device starts in STA_CONNECTING.
• It joins the configured network during the initial STA-only window.
• The AP never appears.

3. WiFi unavailable at boot, fallback AP allowed forever

• The device starts in STA_CONNECTING.
• After the initial timeout, it switches to AP_STA.
• The AP becomes available and stays available.
• STA keeps retrying in the background until WiFi comes back.
• Once STA connects, the AP disappears and the device returns to STA.

4. WiFi unavailable at boot, fallback AP has timeout

• The device starts in STA_CONNECTING.
• It moves to AP_STA after the initial timeout.
• If nobody uses the AP and the AP+Client timeout expires, WiFi turns OFF.
• If retry is enabled, the device waits for the retry interval and starts over from STA_CONNECTING.
• This cycle repeats until STA eventually connects, or until retry is disabled.

5. AP is actively used during fallback

• The device is in AP_STA.
• While at least one AP client is connected, the AP idle timer is effectively pushed forward.
• The timeout only matters after the last AP client disconnects.

6. STA drops after it was working

• The device leaves STA and enters STA_CONNECTING.
• It first tries to recover in STA-only mode again.
• If WiFi returns quickly, the device goes back to STA without broadcasting an AP.
• If WiFi does not return in time, the device falls back to AP_STA.

7. Retry after OFF disabled

• The device can still reach OFF after the AP+Client timeout.
• Once in OFF, it stays there until manual intervention or reboot.

8. Low power mode

• In paths where WiFi would normally transition to OFF, the device sends a status packet and restarts instead.