---
title: "MQTT"
date: 2025-01-27
draft: false
description: "a description"
tags: ["mqtt", "esp"]
---
# MQTT
A configured MQTT server will receive statistical and status data from the controller.

### Topics

| Topic | Example | Description |
|-------|---------|-------------|
| `firmware/address` | `192.168.1.2` | IP address in station mode |
| `firmware/state` | `VersionInfo { ... }` | Debug information about the current firmware and OTA slots |
| `firmware/last_online` | `2025-01-22T08:56:46.664+01:00` | Last time the board was online |
| `state` | `online` | Current state of the controller |
| `mppt` | `{"current_ma":1200,"voltage_ma":18500}` | MPPT charging metrics |
| `battery` | `{"Info":{"voltage_milli_volt":12860,"average_current_milli_ampere":-16,...}}` | Battery health and charge data |
| `water` | `{"enough_water":true,"warn_level":false,"left_ml":1337,...}` | Water tank status |
| `plant{1-8}` | `{"sensor_a":...,"sensor_b":...,"mode":"TargetMoisture",...}` | Detailed status for each plant slot |
| `pump{1-8}` | `{"enabled":true,"pump_ineffective":false,...}` | Metrics for the last pump activity |
| `light` | `{"enabled":true,"active":true,...}` | Night light status |
| `deepsleep` | `night 1h` | Why and how long the ESP will sleep |

### Data Structures

#### Firmware State (`firmware/state`)
Contains a debug dump of the `VersionInfo` struct:
- `git_hash`: Branch and commit hash
- `build_time`: Compilation timestamp
- `current`: Current running partition
- `slot0_state`: State of OTA slot 0
- `slot1_state`: State of OTA slot 1

#### MPPT (`mppt`)
- `current_ma`: Solar charging current in mA
- `voltage_ma`: Solar panel voltage in mV

#### Battery (`battery`)
Can be `"Unknown"` or an `Info` object:
- `voltage_milli_volt`: Battery voltage
- `average_current_milli_ampere`: Current draw/charge
- `design_milli_ampere_hour`: Battery capacity
- `remaining_milli_ampere_hour`: Remaining capacity
- `state_of_charge`: Charge percentage (0-100)
- `state_of_health`: Health percentage (0-100)
- `temperature`: Temperature in degrees Celsius

#### Water (`water`)
- `enough_water`: Boolean, true if level is above empty threshold
- `warn_level`: Boolean, true if level is below warning threshold
- `left_ml`: Estimated remaining water in ml
- `percent`: Estimated fill level in percent
- `raw`: Raw sensor voltage in mV
- `sensor_error`: Details if the level sensor fails
- `water_frozen`: Boolean, true if temperature is below freezing
- `water_temp`: Water temperature in degrees Celsius
- `temp_sensor_error`: Details if the temperature sensor fails

#### Plant (`plant{1-8}`)
- `sensor_a` / `sensor_b`: Moisture sensor status
    - `Disabled`
    - `{"MoistureValue":{"raw_hz":5000,"moisture_percent":65}}`
    - `{"SensorError":{"ShortCircuit":{"hz":...,"max":...}}}`
- `mode`: Watering mode (`Off`, `TargetMoisture`, `MinMoisture`, `TimerOnly`)
- `do_water`: Boolean, true if watering is currently required
- `dry`: Boolean, true if moisture is below target
- `cooldown`: Boolean, true if the pump is in cooldown period
- `out_of_work_hour`: Boolean, true if currently outside allowed watering hours
- `consecutive_pump_count`: Number of pump cycles without reaching target
- `pump_error`: Details if the pump is failing
- `last_pump`: Timestamp of last activity
- `next_pump`: Estimated timestamp for next allowed activity

#### Pump (`pump{1-8}`)
- `enabled`: Boolean, pump was active
- `pump_ineffective`: Boolean, no flow detected during pumping
- `median_current_ma`: Median pump current
- `max_current_ma`: Peak pump current
- `min_current_ma`: Minimum pump current

#### Light (`light`)
- `enabled`: Boolean, is enabled in config
- `active`: Boolean, led is currently on
- `out_of_work_hour`: Boolean, led should not be on at this time of day
- `battery_low`: Boolean, battery is low so led usage is restricted
- `is_day`: Boolean, the sun is up (determined by solar panel voltage)