OWB Monitor - Firmware Config

The OWB monitor runs thesada-fw on a LILYGO T-SIM7080-S3. This page covers the OWB-specific configuration.

Hardware

Component	Details
Board	LILYGO T-SIM7080-S3 (ESP32-S3 + SIM7080G + AXP2101)
Temperature	4x DS18B20 on GPIO12 (1-Wire bus)
Current	ADS1115 with 2x SCT-013-030 CT clamps (I2C SDA=1, SCL=2)
Battery	18650 LiPo via AXP2101, solar input
Connectivity	WiFi primary, LTE-M cellular fallback

config.json

The full config lives on LittleFS at /config.json. Edit via the web UI, HTTP API, or MQTT CLI.

Key sections for OWB

WiFi + MQTT:

"wifi": {
  "networks": [
    { "ssid": "YourIOT", "password": "your-password" }
  ],
  "ap_password": "changeme",
  "ap_timeout_s": 300
},
"mqtt": {
  "broker": "mqtt.example.com",
  "port": 8883,
  "user": "mqtt",
  "password": "your-mqtt-password",
  "topic_prefix": "thesada/owb",
  "ha_discovery": true,
  "buffer_in": 4096,
  "buffer_out": 4096
}

Temperature sensors (DS18B20):

"temperature": {
  "pin": 12,
  "interval_s": 60,
  "auto_discover": true,
  "conversion_wait_ms": 850,
  "read_retries": 2,
  "max_delta_c": 40,
  "unit": "F",
  "sensors": [
    { "address": "28...", "name": "House Supply" },
    { "address": "28...", "name": "House Return" },
    { "address": "28...", "name": "Barn Supply" },
    { "address": "28...", "name": "Barn Return" }
  ]
}

Set auto_discover: true on first boot to detect sensor addresses automatically
After discovery, sensor addresses and names are saved to config
conversion_wait_ms: 850 gives reliable reads on long wire runs (default 750)
unit: "F" publishes in Fahrenheit (thresholds in alert scripts always use Celsius)
read_retries: 2 re-reads a probe on a transient bus fault before reporting it disconnected (default 2). DS18B20 scratchpad CRC is always checked by the driver; this adds retries on top.
max_delta_c: 40 rejects a reading that jumps more than 40 C from the last good value and reports disconnected instead - guards against marginal-bus garbage (long flying leads can read wildly wrong but CRC-valid). Set 0 to disable.

Multiple 1-Wire buses: to drive more than one bus, replace the scalar pin with a buses list. Each bus gets its own GPIO; probes from all buses aggregate into one sensor list (DS18B20 ROM addresses are globally unique):

"temperature": {
  "buses": [ { "pin": 9 }, { "pin": 10 } ],
  "auto_discover": true
}

The scalar pin form still works and is treated as a single bus.

Live probe management: attach or swap a probe without rebooting - run temp.discover over the CLI to re-walk every bus and pick up new probes; temp.discover --prune drops probes that no longer respond and clears their stale entries.

Current sensing (ADS1115 + CT clamps):

"ads1115": {
  "i2c_sda": 1,
  "i2c_scl": 2,
  "address": 72,
  "interval_s": 60,
  "line_voltage": 120,
  "channels": [
    { "name": "House Pump", "mux": "A0_A1", "gain": 0.256, "clamp_a_per_v": 30 },
    { "name": "Barn Pump", "mux": "A2_A3", "gain": 0.256, "clamp_a_per_v": 30 }
  ]
}

line_voltage: 120 - used for power (watts) calculation. Update if your supply voltage differs.
clamp_a_per_v: 30 - CT clamp ratio, amps per 1 V of output. SCT-013-030 = 30, SCT-013-005 = 5. Defaults to 30 if omitted.
RMS sampling: 30 samples over 2x 60Hz cycles for accurate AC current measurement

Multiple ADS1115 chips: to read more than 4 channels, wire a second ADS1115 at a different I2C address (ADDR pin to VDD = 0x49) and list both under devices. Each device carries its own channels; i2c_sda / i2c_scl / interval_s / line_voltage stay shared at the top level:

"ads1115": {
  "i2c_sda": 1,
  "i2c_scl": 2,
  "interval_s": 60,
  "line_voltage": 120,
  "devices": [
    { "address": 72, "channels": [ { "name": "House Pump", "mux": "A0_A1", "gain": 0.256 } ] },
    { "address": 73, "channels": [ { "name": "Barn Pump",  "mux": "A0_A1", "gain": 0.256 } ] }
  ]
}

The scalar address + top-level channels form still works and is treated as a single device.

Telegram alerts:

"telegram": {
  "bot_token": "your-bot-token",
  "chat_ids": ["your-chat-id"]
}

Alert logic is in /scripts/rules.lua on LittleFS (hot-reloadable, no recompile needed).

Deployment

First flash (USB):

cd base
cp examples/config.json.example data/config.json
# edit config.json with your WiFi, MQTT, sensor names
pio run -e esp32-owb --target upload
pio run -e esp32-owb --target uploadfs

Subsequent updates (OTA):

The node checks GitHub releases every 6 hours and auto-updates. Or trigger manually:

# Via MQTT CLI
mosquitto_pub ... -t 'thesada/owb/cli/ota.check' -m ''

# Via HTTP (if on same network)
curl -u admin:changeme -X POST http://<node-ip>/ota -F 'firmware=@build/firmware.bin'

Push scripts remotely:

printf '/scripts/rules.lua\n' > /tmp/payload.bin
cat rules.lua                >> /tmp/payload.bin
mosquitto_pub ... -t 'thesada/owb/cli/fs.write' -f /tmp/payload.bin
mosquitto_pub ... -t 'thesada/owb/cli/lua.reload' -m ''

MQTT topics

All sensor data publishes to per-sensor topics under the configured prefix:

Topic	Value
`thesada/owb/sensor/temperature/house_supply`	`65.20`
`thesada/owb/sensor/temperature/house_return`	`57.10`
`thesada/owb/sensor/current/house_pump`	`0.70`
`thesada/owb/sensor/power/house_pump`	`84.0`
`thesada/owb/sensor/battery/percent`	`100`
`thesada/owb/status`	`online` / `offline` (LWT)
`thesada/owb/alert`	alert messages from rules.lua

Home Assistant picks these up automatically via MQTT auto-discovery (when ha_discovery: true).

Verification

After deployment, verify with the MQTT CLI:

mosquitto_pub ... -t 'thesada/owb/cli/version' -m ''
mosquitto_pub ... -t 'thesada/owb/cli/sensors' -m ''
mosquitto_pub ... -t 'thesada/owb/cli/selftest' -m ''

Or via the web dashboard at http://<node-ip>/ (login: admin/changeme).