Configuration keys

All keys can be sent from the server (…/<mac>/config, retained JSON), from the web interface (Configuration tab), or over USB serial as one JSON line. N = slot number. Keys marked reboot make the node restart about 1 second after being applied; otherwise they take effect immediately. How cfg_ver, rejected, and the retained rules work is in Config and reports.

Connection

Key	Type	Default	Notes
`mqtt_host`	text, max. 63	`auto`	`auto` = gateway IP from DHCP. reboot
`mqtt_mode`	enum	`auto`	`auto`, `mqtt3`, `mqtt5`, `mqtts3`, `mqtts5` (Network and connection modes). reboot
`mqtt_port`	integer 0 … 65535	`0`	non-TLS port; `0` = the type’s default (11883 / 11884). reboot
`mqtts_port`	integer 0 … 65535	`0`	TLS port; `0` = 18883. reboot
`mqtt_ca`	PEM text, max. 3000	empty	private CA for TLS, replacing the public bundle. Its value is not in the report, only its summary. reboot
`ntp_server`	text, max. 63	`auto`	NTP server. Effective list in `ntp_server_effective`. reboot
`workspace`, `channel`	text, max. 64	empty	both filled = direct mode. reboot
`mqtt_user`, `mqtt_pass`	text, max. 64 / 128	empty	direct mode: device ID and device key. `mqtt_pass` is write-only. reboot
`label`	text, max. 20	empty	location name on the LCD
`hw`	text, max. 8	`A`	hardware revision, set during assembly

Telemetry

Key	Type	Default	Range	Notes
`payload_format`	text	`flat2` (new units)	`flat`, `senml`, `flat2`	payload format (Payload formats). reboot
`telemetry_interval_ms`	integer	`10000`	5000 … 3600000	regular send interval
`temp_report_delta_c`	decimal	`0.5`	0 … 20	send early if a slot’s temperature changes by this much; `0` = disabled
`power_report_delta_w`	decimal	`10`	0 … 5000	send early if power changes by this many watts (absolute); `0` = disabled
`hist_kb`	integer	`2048`	0 … 6144	history buffer in PSRAM (KiB), direct mode only with `flat2`. `0` = disabled. `hist_effective_kb` in the report = the size actually active. reboot

Telemetry is also sent early when the alarm level changes and when a sensor disappears or returns; the minimum gap between sends is 2 seconds.

Global sensors

Key	Type	Default	Notes
`pzem`	boolean	`true`	the PZEM-004T is read and power metrics are sent
`sht41`	boolean	`false`	SHT41 installed. reboot
`temp_autobind`	boolean	`true`	a new DS18B20 is automatically bound to the lowest empty temperature slot

Temperature slots `t1` … `t4`

Key	Type	Default	Range	Notes
`tN_en`	boolean	`true`		`false` turns the slot off
`tN_label`	text	`T1`…	max. 12 ASCII	name for humans and the LCD
`tN_name`	text	empty	`[a-z][a-z0-9_]`, max. 24	metric name; empty = slot ID
`tN_rom`	text	empty	16 hex starting with `28`	the ROM of the bound sensor
`tN_offset_c`	decimal	`0`	−10 … 10	calibration
`tN_warn_c`, `tN_alarm_c`	decimal	`-1`	−1 … 125	per-slot limits; `-1` = follow default, `0` = disabled

Digital inputs `d1` … `d4`

Key	Type	Default	Range	Notes
`dN_type`	text	`off`	`off`, `door`, `ups`, `water`, `smoke`, `generic`
`dN_active`	text	`high`	`high`, `low`	the pin level that means active
`dN_name`	text	empty	like `tN_name`	metric name
`dN_label`	text	`D1`…	max. 11 ASCII
`dN_text_true`, `dN_text_false`	text	empty	max. 8 ASCII	LCD status text
`dN_alarm`	boolean	`false`		may trigger an alarm
`dN_alarm_on`	text	`active`	`active`, `inactive`
`dN_alarm_delay_s`	integer	`-1`	−1 … 3600	`-1` = follow `alarm_delay_s`

Digital outputs `o1` … `o4`

Key	Type	Default	Notes
`oN_en`	boolean	`false`	slot enabled
`oN_active`	text	`low`	`high` / `low`: the pin level that means ON
`oN_label`	text	`O1`…	max. 11 ASCII
`oN_name`	text	empty	metric name

Alarms

Key	Type	Default	Range	Notes
`temp_warn_c`	decimal	`30`	0 … 125	default temperature warning; must be < `temp_alarm_c`
`temp_alarm_c`	decimal	`35`	0 … 125	default temperature alarm
`temp_alarm_hyst_c`	decimal	`1`	0 … 10	temperature hysteresis
`alarm_delay_s`	integer	`30`	0 … 3600	delay for all alarms
`volt_min_v`, `volt_max_v`	decimal	`0`	0 … 300	`volt_min_v` < `volt_max_v`
`current_max_a`	decimal	`0`	0 … 100
`power_max_w`	decimal	`0`	0 … 25000
`alarm_buzzer`	boolean	`true`		buzzer on alarm
`maintenance_until`	integer	`0`	epoch seconds	maintenance mode; needs a synchronized clock

Display and buttons

Key	Type	Default	Range	Notes
`lcd`	boolean	`true`		LCD installed. reboot
`lcd_backlight_s`	integer	`120`	0 … 3600	`0` = always on
`lcd_idle_s`	integer	`60`	0 … 3600	return to the Summary; `0` = never
`tz_offset_min`	integer	`420`	−720 … 840	time zone of the LCD clock and rule schedules
`buttons_locked`	boolean	`false`		the Actions item in the LCD menu is disabled
`exp_addr`	integer	`33` (0x21)	32 … 39 or 56 … 63	PCF8574 I2C address. reboot
`lcd_addr`	integer	`0`	0 or like `exp_addr`	`0` = automatic; must not equal `exp_addr`. reboot

Firmware target

Key	Type	Notes
`fw_version`	text	target version; empty = no target
`fw_url`	text	`.bin` address; starting with `/` = from the gateway
`fw_sha256`	text	the file’s SHA-256, 64 hex

Details: Firmware and OTA.

Metric names: rules

Apply to tN_name, dN_name, oN_name, and Modbus source metric names:

lowercase letters, digits, _; starts with a letter; max. 24 characters;
unique across all slots (an empty name counts as the slot ID); swapping the names of two slots in one message is allowed;
must not start with alarm_, rule_, flag_, src_, and must not be a fixed name: voltage, current, power_draw, energy, frequency, power_factor, temp_ambient, humidity, maintenance, uptime, heap_free, state, fw, model, hw, ip, gateway, button;
renaming starts a new data series; moving a name to another slot does not.