Powersaving on companion when serial is off (ble/wifi)

[weebl2000]

Summary

Adds power saving to the companion radio when BLE/WiFi is disabled by the user. When the serial interface is off (and GPS is not enabled), the device enters ESP32-S3 light sleep for 30-minute intervals, significantly reducing power consumption for battery-powered companion nodes that are left running as pure relays.

Changes

Light sleep in companion radio (examples/companion_radio/main.cpp)

• Enters 30-minute light sleep cycles when serial_interface.isEnabled() is false and GPS is off
• Wakes on: LoRa packet (ext1), timer (30min), or button press (GPIO wakeup)
• Stays awake briefly after wake to process any pending work before sleeping again
• Initial 2-minute delay before first sleep to allow setup/connection

WiFi radio actually turns off (src/helpers/esp32/SerialWifiInterface.cpp/h)

• disable() now calls WiFi.disconnect(true) and WiFi.mode(WIFI_OFF) to power down the radio
• enable() reconnects using stored SSID/password credentials
• Previously disable() only set a flag — the WiFi radio stayed powered on

Button wakeup with correct polarity (src/helpers/ESP32Board.h)

• enterLightSleep() accepts optional pin_wake_btn parameter (backward-compatible)
• Uses GPIO wakeup (GPIO_INTR_LOW_LEVEL) for button — correct for active-LOW buttons
• Keeps ext1 (ANY_HIGH) for LoRa DIO1 only — these can't share a mask since they need opposite trigger levels

Pending work detection (examples/companion_radio/MyMesh.cpp/h)

• hasPendingWork() checks outbound packet queue to avoid sleeping while packets are queued

Notes

• Only affects ESP32-S3 targets (gated by CONFIG_IDF_TARGET_ESP32S3)
• Boards without PIN_USER_BTN gracefully skip button wakeup
• GPS-enabled nodes skip sleep entirely (GPS needs continuous operation)
• No changes to the repeater sleep path — sleep() still calls enterLightSleep(secs) without button

[weebl2000]

Moved button handling logic to ESP32Board - this has the added benefit that repeaters will also wake up when you press the button (they do not currently).

[weebl2000]

@fschrempf Actually basically all devices are low when pressed. Updated the code accordingly.

On my Heltec v4 the screen turns off when I disable bluetooth.