All configuration is stored in NVS (Non-Volatile Storage) and survives power cycles. Settings can be changed via the CONFIG portal or by editing firmware constants.

Firmware Constants

Info

These constants are compile-time defaults. Change them before flashing, or use the CONFIG portal to modify at runtime.

Radio Settings

CODE

#define DEFAULT_FREQ_MHZ      433.500f   // Default frequency (MHz)
#define DEFAULT_POWER_DBM     17         // TX power (dBm) -- up to 22 via RadioLib
#define DEFAULT_SLEEP_SEC     10         // Deep sleep between TX cycles (s)
#define DEFAULT_REPEAT_COUNT  3          // Message repetitions per frequency

Morse Settings

CODE

#define DEFAULT_MESSAGE       "SOS"      // Base Morse message
#define DEFAULT_WPM           13         // Words per minute

Audio Settings

CODE

#define DEFAULT_AUDIO_VOL     180        // 0-255 DAC volume
#define DEFAULT_AUDIO_ENABLE  true       // Audio on/off

Display Settings

CODE

#define DEFAULT_OLED_ENABLE   true       // OLED on/off
#define DEFAULT_OLED_INVERT   false      // Invert colors for sunlight

Scan Settings

CODE

#define DEFAULT_SCAN_DWELL_MS 400        // RSSI dwell time per frequency (ms)
#define DEFAULT_RSSI_THRESH   -90        // Detection threshold (dBm)

Battery Settings

CODE

#define BAT_VREF_MV           3900       // ADC full-scale voltage in mV
#define BAT_SAMPLES           32         // ADC samples per reading
#define BAT_READ_MS           5000       // Battery read interval (ms)

GPS Settings

CODE

#define GPS_FIX_TIMEOUT_S     60         // Max seconds to wait for fix
#define GPS_MIN_SATS          3          // Minimum satellites for valid fix

NVS Keys

All settings live in the ESP32 Non-Volatile Storage under the namespace aegis. The exact keys below match the firmware Preferences reads/writes.

Key	Type	Default	Range / Notes
`fcount`	uint8	1	1-10 frequencies
`freq0`..`freq9`	float	433.500	MHz, one key per frequency slot
`msg`	string	“SOS”	Max 64 chars, A-Z 0-9 space
`wpm`	uint8	13	5-40
`pwr`	int8	17	-9 to +22 dBm
`sleep`	ulong	10	Deep sleep seconds between TX cycles
`dwell`	uint16	400	50-2000 ms scan dwell time
`rssi`	int8	-90	-120 to -40 dBm detection threshold
`mode`	uint8	0	0=BEACON 1=SEARCH 2=CONFIG 3=EMERGENCY
`aswitch`	bool	false	Auto-switch to BEACON on low battery
`rep`	uint8	1	1-10 message repetitions per frequency
`avol`	uint8	180	0-255 DAC volume
`aen`	bool	true	Master audio enable
`olen`	bool	true	OLED enable
`olinv`	bool	false	OLED invert mode
`gpsen`	bool	false	GPS module enable
`gpsbeac`	bool	false	Include GPS coords in Morse payload
`gpstmo`	uint8	30	GPS fix wait timeout (10-120 s)
`namen`	bool	false	Include name in Morse payload
`fname`	string	""	First name (max 32 chars)
`lname`	string	""	Last name (max 32 chars)
`poten`	bool	false	SW_UP/DN volume adjust enable
`potwpm`	bool	false	SW_UP/DN WPM adjust enable

Note

Key names are intentionally short (NVS has per-key overhead). freq0..freq9 are separate keys, not an array.

Fail-safe: if NVS is empty, corrupt, or missing any key, the firmware falls back to the hardcoded defaults in the section above. The device is always functional after a factory reset or first flash.

Button Reference

Button	GPIO	Press	Duration	Action
SW_MODE	33	Short	< 2s	Toggle BEACON/SEARCH
SW_MODE	33	Long	>= 2s	Activate EMERGENCY
SW_SEL	32	Short	< 3s	Toggle VOL/WPM target
SW_SEL	32	Long	>= 3s	Launch WiFi AP
SW_SEL	32	Hold	>= 1s	Save to NVS
SW_UP	35	Short	—	Increment parameter
SW_UP	35	Hold	> 500ms	Auto-repeat increment
SW_DN	34	Short	—	Decrement parameter
SW_DN	34	Hold	> 500ms	Auto-repeat decrement
MODE+SEL	33+32	Both	>= 5s	Factory reset

Warning

Factory reset erases all NVS configuration. Device reboots with default settings.

Factory Reset Procedure

Power on device
Hold both MODE and SEL buttons
Keep holding for 5 seconds
Device reboots with default configuration
Reconfigure via CONFIG portal

Calibration

Battery Voltage

If readings differ from multimeter measurement:

CODE

#define BAT_VREF_MV   3900   // Increase if too low, decrease if too high

Audio Volume

Default 180 (~70%). Adjust via UP/DN buttons when VOL is selected.

Morse Speed

Default 13 WPM. Adjust via UP/DN buttons when WPM is selected.

Tip

Hold SEL for 1 second to save current VOL and WPM to NVS. Values persist across power cycles.