Initial project: XIAO ESP32S3 + SX1262 LoRa sensor link hytte–hjem

- cabin_node: subscribes to local MQTT (ESPHome sensors), sends
  temperature, battery voltage/SOC and switch states over LoRa SF12
- cabin_gw: receives LoRa packets, publishes JSON to home MQTT broker
- Bidirectional: gateway forwards ON/OFF commands from home HA to node
- cabin_node always in RX mode (12V powered) — commands arrive instantly
- ESPHome config for ESP32 on teknisk rom: Victron MPPT BLE + JBD BMS
  BLE + DS18B20 temperatures + GPIO switches for varme/VVB

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

esphome/cabin_tech.yaml

@@ -0,0 +1,169 @@
+substitutions:
+  device_name: cabin-tech
+  friendly_name: "Hytte teknisk"
+
+esphome:
+  name: ${device_name}
+  friendly_name: ${friendly_name}
+
+esp32:
+  board: esp32dev
+  framework:
+    type: arduino
+
+logger:
+api:
+  encryption:
+    key: !secret api_key
+
+ota:
+  - platform: esphome
+    password: !secret ota_password
+
+wifi:
+  ssid: !secret wifi_ssid
+  password: !secret wifi_password
+
+mqtt:
+  broker: !secret mqtt_broker
+  port: 1883
+  username: !secret mqtt_username
+  password: !secret mqtt_password
+  topic_prefix: hytte
+
+# ── BLE ──────────────────────────────────────────────────────────────────────
+
+esp32_ble_tracker:
+  scan_parameters:
+    active: false  # passive scanning — don't connect, just listen
+
+# Victron MPPT (SmartSolar) — reads BLE advertisements
+# Get the encryption key from Victron Connect app:
+#   Settings → Product info → Encryption key
+victron_ble:
+  - id: victron_mppt
+    mac_address: !secret victron_mac
+    bindkey: !secret victron_bindkey
+
+sensor:
+  - platform: victron_ble
+    victron_ble_id: victron_mppt
+    battery_voltage:
+      name: "Batteri spenning"
+      id: batt_voltage
+      on_value:
+        then:
+          - mqtt.publish:
+              topic: hytte/sensor/batt_mv
+              payload: !lambda 'return to_string((int)(x * 1000));'
+    battery_current:
+      name: "Batteri strøm"
+    pv_power:
+      name: "Solcelle effekt"
+    load_power:
+      name: "Last effekt"
+    charging_mode:
+      name: "Lademodus"
+
+# JBD/JBD BMS — active BLE client connection
+# External component: https://github.com/syssi/esphome-jbd-bms
+external_components:
+  - source: github://syssi/esphome-jbd-bms@main
+    refresh: 0d
+
+ble_client:
+  - mac_address: !secret jbd_mac
+    id: jbd_ble_client
+
+jbd_bms:
+  - ble_client_id: jbd_ble_client
+    id: jbd
+    update_interval: 60s
+
+sensor:
+  - platform: jbd_bms
+    jbd_bms_id: jbd
+    state_of_charge:
+      name: "Batteri SOC"
+      id: batt_soc
+      on_value:
+        then:
+          - mqtt.publish:
+              topic: hytte/sensor/batt_pct
+              payload: !lambda 'return to_string((int)x);'
+    total_voltage:
+      name: "Total spenning"
+    current:
+      name: "Strøm"
+    power:
+      name: "Effekt"
+    temperature_1:
+      name: "BMS temperatur"
+
+# ── Temperatur ────────────────────────────────────────────────────────────────
+# DS18B20 one-wire — juster pin etter installasjon
+one_wire:
+  - platform: gpio
+    pin: GPIO4
+
+sensor:
+  - platform: dallas_temp
+    name: "Inne temperatur"
+    id: temp_in
+    address: !secret ds18b20_indoor_addr
+    update_interval: 60s
+    on_value:
+      then:
+        - mqtt.publish:
+            topic: hytte/sensor/temp_inne
+            payload: !lambda 'return to_string(x);'
+
+  - platform: dallas_temp
+    name: "Ute temperatur"
+    id: temp_out
+    address: !secret ds18b20_outdoor_addr
+    update_interval: 60s
+    on_value:
+      then:
+        - mqtt.publish:
+            topic: hytte/sensor/temp_ute
+            payload: !lambda 'return to_string(x);'
+
+# ── Bryterkanaler (styres via LoRa-kommandoer) ───────────────────────────────
+
+switch:
+  - platform: gpio
+    name: "Varme"
+    id: switch_varme
+    pin: GPIO16          # juster pin etter installasjon
+    restore_mode: RESTORE_DEFAULT_OFF
+
+  - platform: gpio
+    name: "Varmtvannsbereder"
+    id: switch_vvb
+    pin: GPIO17          # juster pin etter installasjon
+    restore_mode: RESTORE_DEFAULT_OFF
+
+# Lytter på kommandoer fra cabin_node (publisert til lokal MQTT)
+# HA hjemme → MQTT på alu → LoRa → cabin_node → lokal MQTT → her
+mqtt:
+  on_message:
+    - topic: hytte/cmd/varme
+      then:
+        - if:
+            condition:
+              lambda: 'return x == "ON";'
+            then:
+              - switch.turn_on: switch_varme
+            else:
+              - switch.turn_off: switch_varme
+
+    - topic: hytte/cmd/vvb
+      then:
+        - if:
+            condition:
+              lambda: 'return x == "ON";'
+            then:
+              - switch.turn_on: switch_vvb
+            else:
+              - switch.turn_off: switch_vvb