wifi cyw43

[k-madsenDK]

Title: Expose CYW43 WiFi power management (powersave/performance) and TX power in Arduino API

Context

• Board: Raspberry Pi Pico W (RP2040 + CYW43)
• Core: Earle Philhower Arduino-Pico
• Use case: Always-on device with webserver/NTP running 24/7
• AP: Ubiquiti/UniFi (common in the field)

Problem
On Pico W the CYW43 driver defaults to a balanced power-save. With certain AP policies (e.g., Group Rekey Interval, inactivity timeouts) we see periodic reconnects, typically every 30/60 minutes. Example log (real device):

[UNSYNCED] WATCHDOG_RESET
[2025-08-17 00:03:03] WIFI_RECONNECT 192.168.7.49
[2025-08-17 00:33:00] WIFI_RECONNECT 192.168.7.49
[2025-08-17 01:02:59] WIFI_RECONNECT 192.168.7.49
[2025-08-17 02:02:59] WIFI_RECONNECT 192.168.7.49
[2025-08-17 02:33:03] WIFI_RECONNECT 192.168.7.49
... (pattern continues throughout the day) ...

Workarounds like periodic UDP keep-alives help, but the robust fix for some deployments is to run the radio in “no powersave” / “performance” mode and/or set a higher TX power. This used to be reachable via low-level cyw43 calls, but those are not exposed in the current Arduino layer.

Request
Please expose a minimal WiFi power management and TX power API at the Arduino level so sketches can control the CYW43 radio without custom CMake builds:

Proposed API (Arduino)

• Power-save control:

  • WiFi.setPowerSave(bool enabled); // enabled=false => no power save
    or
  • WiFi.setPowerMode(WIFI_PM_NONE | WIFI_PM_DEFAULT | WIFI_PM_PERFORMANCE);

• TX power (if supported by the driver/firmware on Pico W):

  • WiFi.setTxPower(int8_t dBm); // clamp to valid range
  • Optional: WiFi.getTxPower();

Rationale

• Keeps Arduino workflow (no CMake), which many users rely on for Pico W.
• Matches what MicroPython exposes via wlan.config(pm=...).
• Helps stabilize long-lived connections on APs that are sensitive to powersave DTIM/PS buffering.
• Avoids ad-hoc hacks in sketches (e.g., synthetic traffic every 30s).

Design sketch (mapping to cyw43)

• Internally map to CYW43 driver:
  • WIFI_PM_NONE -> cyw43_wifi_pm(..., CYW43_NO_POWERSAVE_MODE) or performance eq.
  • WIFI_PM_DEFAULT -> cyw43_wifi_pm(..., CYW43_DEFAULT_PM)
  • WIFI_PM_PERFORMANCE -> cyw43_wifi_pm(..., CYW43_PERFORMANCE_PM) (if available)
• Guard with #ifdefs for driver variants; return bool for success/failure.

Backward compatibility

• Default behavior unchanged (keep current balanced powersave).
• New API is opt-in for users who need it.

Alternatives considered

• Keep-alive traffic: works but wastes airtime/power and doesn’t fix root cause.
• User-side CMake build and custom core patches: heavy for Arduino users.
• MicroPython: too slow/unsuitable for some real-time/web workloads on RP2040.

Environment evidence

• Real-world logs show periodic reconnects under UniFi even with strong RSSI.
• Disabling powersave on similar platforms often eliminates periodic kicks.

Related

• Ideas category: wifi cyw43 (wifi cyw43 #3080)
• Please consider also a Tools menu item (Pico W WiFi Power Save: Default/Off/Performance) for quick testing.

Example usage
void setup() {
WiFi.begin(ssid, pass);
if (WiFi.waitForConnectResult() == WL_CONNECTED) {
WiFi.setPowerMode(WIFI_PM_NONE); // or WiFi.setPowerSave(false);
// Optionally: WiFi.setTxPower(10); // if supported
}
}

Thanks for maintaining the Pico W support — exposing these knobs would solve practical field issues without forcing users off the Arduino toolchain.

[earlephilhower]

Power mode is already exposed

arduino-pico/libraries/WiFi/src/WiFiClass.h

Lines 409 to 412 in c2fe192

	void aggressiveLowPowerMode();
	void defaultLowPowerMode();
	#endif
	void noLowPowerMode();

After WiFi.begin you can call one of those to set the driver config

[k-madsenDK]

thx :-)