Mapping OTthing sensors for SAT #134

sergeantd83 · 2025-12-22T19:34:21Z

sergeantd83
Dec 22, 2025
Collaborator

Part I ( Mapping EMS/ESP32 sensors for SAT )

SAT	OT Thing	UOM	Read / Write	Description	MsgID
DATA_FLAME_ACTIVE	flame	Binary	R	Whether the flame is ON or OFF	0:LB3
DATA_DHW_SETPOINT	dhw_set_t	°C	R / W	The DHW setpoint	56
DATA_CONTROL_SETPOINT	ch_set_t	°C	W	The Boiler flow water temperature setpoint	1
DATA_REL_MOD_LEVEL	rel_mod	%	R	The current boiler modulation	17
DATA_BOILER_TEMPERATURE	flow_t	°C	R	The boiler flow water temperature	25
DATA_RETURN_TEMPERATURE		°C	R	The return water temperature	28
DATA_DHW_ENABLE	dhw_mode	Binary	R	When the DHW is in use	0:LB2
DATA_CENTRAL_HEATING	ch_mode	Binary	R	When the thermostat asks for heating	0:LB1
DATA_SLAVE_MEMBERID	memberId	Integer	R	The unique number of the Boiler Manufacturer	3:LB
DATA_BOILER_CAPACITY		kW	R	The Rated maximum power in kW of the boiler	15
DATA_REL_MIN_MOD_LEVEL		%	R		15
DATA_MAX_REL_MOD_LEVEL_SETTING		%	W	The maximum allowable power of the boiler	14
DATA_DHW_SETPOINT_MINIMUM	dhwMin	°C	R	The min value for the DHW setpoint	48
DATA_DHW_SETPOINT_MAXIMUM	dhwMax	°C	R	The max value for the DHW setpoint	48

Part II ( Boiler control )

OTGW Command Payload	OT Thing Command Payload	Description
`await self._send_command(f"CH={1 if state == DeviceState.ON else 0}")`		The CH command starts / stops the heating
`await self._send_command(f"CS={value}")`		The CS command manipulates the boiler flow water setpoint
`await self._send_command(f"MM={value}")`		The MM command manipulates the maximum modulation of the boiler
`await self._send_command(f"SW={value}")`		The SW command changes the DHW setpoint
`await self._send_command(f"SH={value}")`		The SH command manipulates the max allowable boiler flow water temperature

Part III ( Command Topic )

OTGW Command Topic	OT Thing Command Topic
`await mqtt.async_publish(self.hass, f"{self._topic}/set/{self._node_id}/command", payload)`

Part IV ( Publish Topic )

OTGW Publish Topic	OT Thing Publish Topic
`OTGW/value/{self._node_id}`

Phunkafizer · 2025-12-22T22:57:33Z

Phunkafizer
Dec 22, 2025

OTthing submits all readable status information in a single MQTT topic:

/state
is "otthing/ by default, but can be configured in OTthing. Exampletopic:

otthing/31F44C/state

Example for the JSON payload sent in this topic:

{
    "runtime": 351450,
    "freeHeap": 158496,
    "resetInfo": 12,
    "fw_version": "2.21",
    "USB_connected": false,
    "reset_reason0": 12,
    "reset_reason1": 1,
    "numWifiDisc": 0,
    "new_fw": "v2.21",
    "dateTime": "22.12.2025 23:21:19",
    "wifi": {
        "status": 3,
        "mode": 1,
        "ipsta": "192.168.178.34",
        "mac": "9C:9E:6E:31:F4:4C",
        "hostname": "otthing",
        "sta_ssid": "abcdefg",
        "rssi": -57
    },
    "mqtt": {
        "connected": true,
        "basetopic": "otthing/31F44C",
        "numDisc": 0
    },
    "slave": {
        "slave_config_member": {
            "value": "4108",
            "dhw_present": true,
            "ctrl_type": false,
            "cooling_config": false,
            "dhw_config": false,
            "master_lowoff_pumpctrl": false,
            "ch2_present": false
        },
        "memberId": 8,
        "status": {
            "value": "30a",
            "fault": false,
            "ch_mode": true,
            "dhw_mode": false,
            "flame": true,
            "cooling": false,
            "ch2_mode": false,
            "diagnostic": false
        },
        "vent_status": null,
        "dhwMax": 65,
        "dhwMin": 5,
        "tr_override": 0,
        "rel_mod": 12,
        "ch_pressure": 1.7,
        "flow_t": 44.7,
        "dhw_t": 35,
        "outside_t": null,
        "unsuccessful_burner_starts": 3,
        "num_flame_signal_low": 188,
        "burner_starts": 13559,
        "burner_op_hours": 19491,
        "dhw_burner_op_hours": 405,
        "fault_flags": null,
        "rp_flags": {
            "value": "101",
            "dhw_setpoint_rw": true,
            "max_ch_setpoint_rw": false,
            "dhw_setpoint_trans": true,
            "max_ch_setpoint_trans": false
        },
        "remote_override_function": {
            "value": "3",
            "manual_change_priority": true,
            "program_change_priority": true
        },
        "connected": true,
        "txCount": 706238,
        "rxCount": 706236,
        "timeouts": 1
    },
    "thermostat": {
        "ch_set_t": 40.6,
        "room_t": 19.8,
        "room_set_t": 22,
        "master_config_member": {
            "value": "116",
            "smartPowerImplemented": false
        },
        "memberId": 22,
        "dhw_set_t": 51,
        "status": {
            "value": "300",
            "ch_enable": true,
            "dhw_enable": true,
            "cooling_enable": false,
            "otc_active": false,
            "ch2_enable": false
        },
        "txCount": 329058,
        "rxCount": 329058,
        "invalidCount": 0,
        "smartPower": "low"
    },
    "heatercircuit": [
        {
            "roomsetpoint": 22,
            "roomtemp": 19.8,
            "ovrdFlow": false,
            "mode": 2
        },
        {
            "ovrdFlow": false,
            "mode": 2
        }
    ],
    "outsideTemp": 0.5,
    "1wire": {
        "2812ba651b1301a4": 33.4,
        "28c070881b130145": 44.7
    }
}

Topics for setting values:
<basetopic>/dwhSetTemp set DHW temperature
<basetopic>/chSetTemp1 set flow temperature channel 1; <basetopic>/chMode1 has to be set to "heat"
<basetopic>/chSetTemp2 set flow temperature channel 2; <basetopic>/chMode2 has to be set to "heat"
<basetopic>/chMode1 "off" switches off channel 1
<basetopic>/chMode2 "off" switches off channel 2
<basetopic>/chMode1 "auto" will let OTthing calculate the flow temperature for channel 1
<basetopic>/chMode2 "auto" will let OTthing calculate the flow temperature for channel 2

0 replies

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Uh oh!

Mapping OTthing sensors for SAT #134

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{editor}}'s edit

{{editor}}'s edit

Uh oh!

Replies: 1 comment

Uh oh!

{{title}}

Uh oh!

Select a reply

Uh oh!

Uh oh!

Mapping OTthing sensors for SAT #134

Uh oh!

Uh oh!

sergeantd83 Dec 22, 2025 Collaborator

Replies: 1 comment

Uh oh!

Phunkafizer Dec 22, 2025

sergeantd83
Dec 22, 2025
Collaborator

Phunkafizer
Dec 22, 2025