# thermal-node-01 — ESPHome device config (ESPHome 2024.6+ syntax)
# Revision 2. Changes from v1:
#  - All thresholds in °C (DS18B20 reports °C; v1's "155" °F threshold could never trip)
#  - Interlocks run ON THE DEVICE, so they work with Home Assistant or MQTT down
#  - Relay moved off GPIO12 (a strapping pin) to GPIO26
#  - Fail-safe: mining is OFF at boot, on any sensor fault, on low flow and on supervisor loss
#  - Real 0–10 V output through a GP8403 DAC; the ESP32 cannot drive 0–10 V directly
# This node is the SECOND layer of protection. The FIRST layer is the hardwired
# coil chain (BESS SOC dry contact → thermal switch → this relay → contactor coil).

substitutions:
  name: thermal-node-01
  trip_supply_c: "65.6"    # 150 °F — set at or below the hydro-miner vendor's max outlet temperature
  warn_supply_c: "62.8"    # 145 °F
  min_flow_gpm: "2.0"      # the vendor's minimum loop flow for the installed fleet
  flow_k_ppg: "100.0"      # PLACEHOLDER pulses per US gallon — use the meter datasheet, then bucket-test

esphome:
  name: ${name}
  on_boot:
    priority: -100
    then:
      - switch.turn_off: mining_relay      # never auto-start mining after a reboot

esp32:
  board: esp32dev
  framework:
    type: esp-idf

logger:

# Prefer wired Ethernet (e.g. an Olimex ESP32-POE-ISO) in plant rooms. Wi-Fi shown for brevity.
wifi:
  ssid: !secret iot_ssid
  password: !secret iot_password

ota:
  - platform: esphome
    password: !secret ota_password

mqtt:
  broker: !secret mqtt_broker          # broker on VLAN 40
  port: 8883
  username: !secret mqtt_user
  password: !secret mqtt_password
  certificate_authority: !secret mqtt_ca_pem
  on_disconnect:
    - switch.turn_off: mining_relay      # supervisor lost → shed (fail-safe)

one_wire:
  - platform: gpio
    pin: GPIO4

i2c:
  sda: GPIO21
  scl: GPIO22

gp8403:
  id: valve_dac
  voltage: 10V

output:
  - platform: gp8403
    id: valve_out
    gp8403_id: valve_dac
    channel: 0

sensor:
  - platform: dallas_temp
    address: 0x2c3c012345678928          # replace with your probe's address from the boot log
    name: "Loop Supply Temp"
    id: supply_temp
    update_interval: 2s
    filters:
      - median:
          window_size: 3
          send_every: 1

  - platform: dallas_temp
    address: 0x2c3c012345678929
    name: "Loop Return Temp"
    id: return_temp
    update_interval: 2s

  - platform: pulse_counter
    pin:
      number: GPIO27
      mode: INPUT_PULLUP
    name: "Primary Loop Flow"
    id: flow_gpm
    unit_of_measurement: "gal/min"
    accuracy_decimals: 2
    update_interval: 5s
    filters:
      - lambda: return x / ${flow_k_ppg};   # pulses/min ÷ pulses/gal = GPM

  - platform: template
    name: "Recovered Heat"
    unit_of_measurement: "kW"
    accuracy_decimals: 2
    update_interval: 10s
    # Q[BTU/h] = k × GPM × ΔT[°F], with k ≈ 480 for 30 % PG; 1 kW = 3412.14 BTU/h
    lambda: |-
      float dT_f = (id(supply_temp).state - id(return_temp).state) * 1.8f;
      return 480.0f * id(flow_gpm).state * dT_f / 3412.14f;

binary_sensor:
  # The relay's hardwired twin: the inverter's SOC dry contact, read back for visibility only
  - platform: gpio
    pin:
      number: GPIO25
      mode: INPUT_PULLUP
      inverted: true
    name: "BESS SOC Permissive (hardwired)"

  # Contactor auxiliary NO contact: reports the ACTUAL bus state, not just the command
  - platform: gpio
    pin:
      number: GPIO33
      mode: INPUT_PULLUP
      inverted: true
    name: "Mining Bus Energized (contactor aux)"
    id: mining_bus_state

  - platform: template
    id: low_flow
    name: "Primary Loop Low Flow"
    lambda: return isnan(id(flow_gpm).state) || id(flow_gpm).state < ${min_flow_gpm};
    filters:
      - delayed_on: 10s

  - platform: template
    id: high_temp_warn
    name: "Loop Supply High Temp Warning"
    lambda: return id(supply_temp).state > ${warn_supply_c};
    on_press:
      - number.set:
          id: valve_pos
          value: 100                       # send all heat to the dry cooler

  - platform: template
    id: interlock_fault
    name: "Mining Interlock Fault"
    device_class: problem
    lambda: |-
      return isnan(id(supply_temp).state) || isnan(id(return_temp).state)
          || id(supply_temp).state > ${trip_supply_c}
          || id(low_flow).state;
    on_press:
      - switch.turn_off: mining_relay
      - logger.log:
          level: ERROR
          format: "INTERLOCK: mining bus shed (temp/flow/sensor fault)"

switch:
  - platform: gpio
    pin: GPIO26
    id: mining_relay
    internal: true
    restore_mode: ALWAYS_OFF

  # Exposed control. Turning ON is refused while any interlock is faulted.
  - platform: template
    name: "Mining Bus Enable"
    id: mining_enable
    lambda: return id(mining_relay).state;
    turn_on_action:
      - if:
          condition:
            binary_sensor.is_off: interlock_fault
          then:
            - switch.turn_on: mining_relay
          else:
            - logger.log:
                level: WARN
                format: "Enable refused: interlock fault active"
    turn_off_action:
      - switch.turn_off: mining_relay

number:
  - platform: template
    name: "Diverter Valve to Dry Cooler"
    id: valve_pos
    unit_of_measurement: "%"
    min_value: 0
    max_value: 100
    step: 1
    optimistic: true
    restore_value: true
    initial_value: 100                     # boot state: reject heat (safe)
    set_action:
      - output.set_level:
          id: valve_out
          level: !lambda return x / 100.0;