NVS Configuration

The firmware stores configuration in the ESP-IDF NVS (Non-Volatile Storage) flash partition under the lora_cfg namespace. Settings persist across reboots.

NVS namespace

Namespace: lora_cfg

Keys

LoRa radio settings

Key	Type	Default	Description
lora_addr	uint16	1	Device LoRa address
lora_dest	uint16	0	Default destination (base station) address
lora_net	uint8	0	Network ID (0–16)
lora_band	uint32	915000000	Frequency in Hz
lora_sf	uint8	9	Spreading factor (7–12)

Camera pipeline settings

Key	Type	Default	Description
cam_period	uint32	0	Periodic capture interval in ms (0 = disabled)
cam_motion	uint8	0	Motion detection enabled (0 or 1)
cam_quality	uint8	12	JPEG quality (0–63 for OV2640, lower = better)

Default behavior

If the lora_cfg namespace doesn’t exist or a key is missing, the firmware uses the hardcoded defaults from load_lora_config() in main.c. This happens on first boot or after an NVS erase.

Runtime updates

The C:CONFIG LoRa command updates in-memory settings but does not persist them to NVS. Settings revert to NVS values on reboot.

To persist changes, NVS must be written explicitly. Currently, NVS is read-only at startup — runtime persistence would require adding nvs_set_* calls to the config command handler.

Spreading factor trade-offs

SF	Range	Airtime	Throughput	Use case
7	Shortest	Fastest	Highest	Short range, fast transfers
9	Medium	Medium	Medium	Default — balanced
12	Longest	Slowest	Lowest	Maximum range, slow transfers

Higher SF values increase range at the cost of much longer per-packet airtime, which directly impacts image transfer duration.

NVS partition layout

NVS occupies 16KB in the partition table:

nvs,  data, nvs,  0x9000, 0x4000  (16KB)

This is sufficient for dozens of key-value pairs. The partition is separate from the OTA app partitions and survives firmware updates.