diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..d338c70
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,12 @@
+# Changelog
+
+## 2025-12-24
+- Ajout d'un scheduler precis par entite avec frequences en secondes/minutes.
+- Lectures Modbus optimisees par batch + publication sur changement uniquement.
+- Reconnexion Modbus avec backoff + backoff par entite en cas d'erreurs.
+- LWT MQTT et publication d'availability automatique.
+- Logs enrichis (niveau configurable, sortie fichier optionnelle) + metrics MQTT.
+- Prise en charge de `state_topic` et `value_map` dans la config.
+- Validation de configuration au demarrage.
+- Ajout d'entites texte pour SystemStatus et FurnaceStatus.
+- Ajout d'un capteur calcule "Stock energie" (kWh) avec volume et Tmin configurables.
diff --git a/Dockerfile b/Dockerfile
index 45b3a0a..85baa73 100755
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,7 +12,7 @@ RUN pip install --no-cache-dir -r requirements.txt
 
 # Copier seulement le fichier main.py et config.yaml dans le conteneur
 COPY ./src/main.py /usr/src/app/main.py
-COPY ./config/config.yaml /usr/src/app/config.yaml
+COPY ./src/config.yaml /usr/src/app/config.yaml
 
 # Commande pour exécuter l'application
-CMD ["python", "./main.py"]
\ No newline at end of file
+CMD ["python", "./main.py"]
diff --git a/PROMPT.md b/PROMPT.md
new file mode 100644
index 0000000..dd178b5
--- /dev/null
+++ b/PROMPT.md
@@ -0,0 +1,37 @@
+# Prompt - Modbus to MQTT App
+
+Use these development guidelines for this repository.
+
+## Goals
+- Keep the app config-driven and backward compatible.
+- Avoid breaking MQTT topics or HA discovery behavior.
+- Prefer readable logs and safe defaults.
+
+## Core behavior
+- Read Modbus registers and publish to MQTT.
+- Support per-entity refresh intervals (seconds or minutes).
+- Use batching for contiguous Modbus reads.
+- Publish only on change by default (configurable).
+- Publish availability (LWT) and metrics.
+
+## Configuration rules
+- `src/config.yaml` is the active config file.
+- Validate config on startup (required fields, unique_id).
+- Support `state_topic` override per entity.
+- Support `value_map` for text mapping.
+- Allow computed entities (`input_type: computed`).
+
+## Reliability
+- Reconnect Modbus with exponential backoff.
+- Backoff per entity after read errors.
+- Keep MQTT connection stable and log failures.
+
+## Observability
+- Log at INFO by default, allow DEBUG via config.
+- Optional file logging via `log_file`.
+- Metrics to `<topic_prefix>/metrics`.
+
+## Changes checklist
+- Update README and CHANGELOG when behavior changes.
+- Keep ASCII where possible (avoid accents in new files).
+- Add minimal comments only when logic is not obvious.
diff --git a/README.md b/README.md
index 42c3e1e..dd6e97d 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,59 @@
 # froling_modbus2mqtt
 
+Passerelle Modbus -> MQTT pour chaudiere Froling, avec autodiscovery Home Assistant.
+
+## Fonctionnement
+- Lit des registres Modbus (input/holding/coils/discrete) et publie sur MQTT.
+- Chaque entite peut avoir sa frequence (secondes ou minutes).
+- Autodiscovery HA publie automatiquement les capteurs.
+- Optimisations: lectures Modbus par batch, publication sur changement uniquement (optionnel).
+- Fiabilite: LWT MQTT + reconnexion Modbus avec backoff.
+
+## Fichier de configuration
+L'application lit `src/config.yaml` (monte dans le conteneur).
+
+Parametres globaux utiles:
+- `refresh_rate`: intervalle par defaut.
+- `log_level` / `log_file`: logs console et fichier optionnel.
+- `publish_on_change_only`: publier uniquement si la valeur change.
+- `metrics_interval`: envoi des metrics MQTT.
+- `buffer_volume_l`, `buffer_min_temp_c`: calcul Stock energie.
+- `modbus.reconnect_min` / `modbus.reconnect_max`: backoff reconnexion.
+
+Parametres par entite:
+- `refresh` + `refresh_unit` (`s` ou `m`)
+- `state_topic` (sinon genere avec `topic_prefix` et `name`)
+- `value_map` (SystemStatus, FurnaceStatus, etc.)
+
+## Entites calculees
+Type `input_type: computed` pour les valeurs derivees.
+
+Exemple Stock energie (kWh) base sur Tampon Haut/Bas:
+```yaml
+buffer_volume_l: 1000
+buffer_min_temp_c: 25
+...
+  - name: "Stock energie"
+    unique_id: "stock_energie_sensor"
+    type: "sensor"
+    unit_of_measurement: "kWh"
+    state_topic: "froling/S3Turbo/STOCK_ENERGIE/state"
+    input_type: "computed"
+    formula: "buffer_energy_kwh"
+    sources:
+      - "tampon_haut_sensor"
+      - "tampon_bas_sensor"
+    precision: 2
+```
+
+## MQTT
+- Availability: `<topic_prefix>/availability`
+- Metrics: `<topic_prefix>/metrics` (reads, errors, published, uptime)
+
+## Lancer en Docker
+```bash
+docker compose up -d --build
+```
+
+## Changelog
+Voir `CHANGELOG.md`.
diff --git a/config/config.yaml b/config/config.yaml.old
similarity index 89%
rename from config/config.yaml
rename to config/config.yaml.old
index 84a10e6..c3b5b3a 100755
--- a/config/config.yaml
+++ b/config/config.yaml.old
@@ -1,22 +1,3 @@
-# Digital Outputs
-# Function: Read Coil Status (FC=01)
-# Address Range: 00001-00158
-
-# Digital Inputs
-# Function: Read Input Status (FC=02)
-# Address Range: 10001-10086
-
-# Actual Values
-# Function: Read Input Registers(FC=04)
-# Address Range: 30001-30272
-# input_type : input
-
-# Parameters
-# Function: Read Holding Registers(FC=03)
-# Address Range: 40001-41094
-# input_type: holding
-
-
 mqtt:
   host: "10.0.0.3"
   port: 1883
@@ -84,8 +65,8 @@ entities:
   - name: "Etats systeme"
     unique_id: "etats_systeme_sensor"
     type: "sensor"
-    #device_class: "enum"
-    #state_class: "measurement"
+   # device_class: "enum"
+   # state_class: "measurement"
     icon: "mdi:radiator"
     unit_of_measurement: ""
     state_topic: "froling/S3Turbo/ETATS_SYSTEME/state"
@@ -97,11 +78,13 @@ entities:
     precision: 1
     value_map: "SystemStatus"
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "Etat Chaudiere"
     unique_id: "etats_chaudiere_sensor"
     type: "sensor"
-    #device_class: "enum"
-    #state_class: "measurement"
+   # device_class: "enum"
+   # state_class: "measurement"
     icon: "mdi:water-boiler-alert"
     unit_of_measurement: ""
     state_topic: "froling/S3Turbo/ETATS_CHAUDIERE/state"
@@ -113,6 +96,8 @@ entities:
     precision: 0
     value_map: "FurnaceStatus"
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "T° Chaudiere"
     unique_id: "temperature_chaudiere_sensor"
     type: "sensor"
@@ -129,6 +114,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "T° Fumee"
     unique_id: "temperature_fumee_sensor"
     type: "sensor"
@@ -145,6 +132,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "T° Board"
     unique_id: "temperature_board_sensor"
     type: "sensor"
@@ -161,6 +150,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "O2 residuel"
     unique_id: "o2_residuel_sensor"
     type: "sensor"
@@ -177,6 +168,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "T° Exterieur"
     unique_id: "temp_exterieur_sensor"
     type: "sensor"
@@ -193,6 +186,8 @@ entities:
     precision: 0
     value_map: null
     signed: true
+    refresh: 1
+    refresh_unit: "m"
   - name: "Porte chaudiere"
     unique_id: "porte_chaudiere_sensor"
     type: "binary_sensor"
@@ -209,6 +204,8 @@ entities:
     offset: 10001
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
  
 
   - name: "Air primaire"
@@ -226,6 +223,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "Air Secondaire"
     unique_id: "air_secondaire_sensor"
     type: "sensor"
@@ -241,6 +240,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "Vitesse ventilateur"
     unique_id: "vitesse_ventilateur_sensor"
     type: "sensor"
@@ -256,6 +257,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "Commande tirage"
     unique_id: "commande_tirage_sensor"
     type: "sensor"
@@ -271,6 +274,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "Consigne T° fumée"
     unique_id: "consigne_temperature_fumee_sensor"
     type: "sensor"
@@ -287,6 +292,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "Consigne T° chauffage"
     unique_id: "consigne_temperature_chauffage_sensor"
     type: "sensor"
@@ -303,6 +310,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "Heure fonctionnement"
     unique_id: "heure_fonctionnement_sensor"
     type: "sensor"
@@ -318,6 +327,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "Heure de maintien de feu"
     unique_id: "heure_maintien_de_feu_sensor"
     type: "sensor"
@@ -333,6 +344,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "Heure chauffage"
     unique_id: "heure_chauffage_sensor"
     type: "sensor"
@@ -348,6 +361,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "Tampon Haut"
     unique_id: "tampon_haut_sensor"
     type: "sensor"
@@ -364,6 +379,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "Tampon Bas"
     unique_id: "tampon_bas_sensor"
     type: "sensor"
@@ -380,6 +397,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
   - name: "T° depart chauffage"
     unique_id: "temperature_depart_chauffage_sensor"
     type: "sensor"
@@ -396,6 +415,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: "Charge tampon"
     unique_id: "charge_tampon_sensor"
     type: "sensor"
@@ -411,21 +432,25 @@ entities:
     precision: 0
     value_map: null
     signed: false
-#   Digital Outputs
-# Function: Read Coil Status (FC=01)
-  - name: pompe circuit chauffage"
-    unique_id: "pompe_circuit_chauffage"
-    type: "binary_sensor"
-    device_class: "running"
-    icon: "mdi:pump"
-    state_topic: "froling/S3Turbo/pump_chauffage/state"
-    value_template: "{{ value_json.charge_tampon_sensor }}"
-    input_type: "coil"
-    address: 30226
+    refresh: 1
+    refresh_unit: "m"
+  - name: "pompe accumulateur"
+    unique_id: "pompe_accu"
+    type: "sensor"
+    device_class: "battery"
+    state_class: "measurement"
+    icon: "mdi:percent-circle-outline"
+    unit_of_measurement: "%"
+    state_topic: "froling/S3Turbo/pompe_accu/state"
+    value_template: "{{ value_json.pompe_accu }}"
+    input_type: "input_register"
+    address: 30141
     offset: 30001
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
 #   Digital Outputs
 # Function: Read Coil Status (FC=01)
   - name: pompe circuit_chauffage
@@ -440,6 +465,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: cc_melangeur_ouvert
     unique_id: "cc_melangeur_ouvert"
     type: "binary_sensor"
@@ -452,6 +479,8 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
   - name: cc_melangeur_ferme
     unique_id: "cc_melangeur_ferme"
     type: "binary_sensor"
@@ -464,4 +493,7 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
+ 
 
diff --git a/docker-compose.yml b/docker-compose.yml
index c89beb9..8084ba2 100755
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,4 +1,4 @@
-version: "3.8"
+#version: "3.8"
 
 services:
   app:
diff --git a/src/config.yaml b/src/config.yaml
index 1aa4ff8..cc8971e 100755
--- a/src/config.yaml
+++ b/src/config.yaml
@@ -15,8 +15,17 @@ modbus:
   port: 502
   unit_id: 2
   timeout: 30
+  reconnect_min: 1
+  reconnect_max: 30
 
 refresh_rate: 10 # Fréquence d'actualisation en secondes
+log_level: "INFO" # DEBUG, INFO, WARNING, ERROR
+log_file: "" # Exemple: "/usr/src/app/logs/app.log"
+error_backoff_max: 300 # secondes, limite max apres erreurs Modbus
+publish_on_change_only: true
+metrics_interval: 60 # secondes
+buffer_volume_l: 1000
+buffer_min_temp_c: 25
 
 device:
   identifiers: "FrolingS3"  # Remplacer par l'identifiant unique du dispositif
@@ -78,6 +87,9 @@ entities:
     precision: 1
     value_map: "SystemStatus"
     signed: false
+    refresh: 5
+    refresh_unit: "m"
+
   - name: "Etat Chaudiere"
     unique_id: "etats_chaudiere_sensor"
     type: "sensor"
@@ -94,6 +106,9 @@ entities:
     precision: 0
     value_map: "FurnaceStatus"
     signed: false
+    refresh: 1
+    refresh_unit: "m"
+
   - name: "T° Chaudiere"
     unique_id: "temperature_chaudiere_sensor"
     type: "sensor"
@@ -110,6 +125,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
+
   - name: "T° Fumee"
     unique_id: "temperature_fumee_sensor"
     type: "sensor"
@@ -126,6 +144,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
+
   - name: "T° Board"
     unique_id: "temperature_board_sensor"
     type: "sensor"
@@ -142,6 +163,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
+
   - name: "O2 residuel"
     unique_id: "o2_residuel_sensor"
     type: "sensor"
@@ -158,6 +182,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "m"
+
   - name: "T° Exterieur"
     unique_id: "temp_exterieur_sensor"
     type: "sensor"
@@ -174,6 +201,9 @@ entities:
     precision: 0
     value_map: null
     signed: true
+    refresh: 1
+    refresh_unit: "m"
+
   - name: "Porte chaudiere"
     unique_id: "porte_chaudiere_sensor"
     type: "binary_sensor"
@@ -190,6 +220,8 @@ entities:
     offset: 10001
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "s"
  
 
   - name: "Air primaire"
@@ -207,6 +239,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
+
   - name: "Air Secondaire"
     unique_id: "air_secondaire_sensor"
     type: "sensor"
@@ -222,6 +257,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
+
   - name: "Vitesse ventilateur"
     unique_id: "vitesse_ventilateur_sensor"
     type: "sensor"
@@ -237,6 +275,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 5
+    refresh_unit: "5"
+
   - name: "Commande tirage"
     unique_id: "commande_tirage_sensor"
     type: "sensor"
@@ -252,6 +293,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
+
   - name: "Consigne T° fumée"
     unique_id: "consigne_temperature_fumee_sensor"
     type: "sensor"
@@ -268,6 +312,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "m"
+
   - name: "Consigne T° chauffage"
     unique_id: "consigne_temperature_chauffage_sensor"
     type: "sensor"
@@ -284,6 +331,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "m"
+
   - name: "Heure fonctionnement"
     unique_id: "heure_fonctionnement_sensor"
     type: "sensor"
@@ -299,6 +349,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 50
+    refresh_unit: "m"
+
   - name: "Heure de maintien de feu"
     unique_id: "heure_maintien_de_feu_sensor"
     type: "sensor"
@@ -314,6 +367,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 50
+    refresh_unit: "m"
+
   - name: "Heure chauffage"
     unique_id: "heure_chauffage_sensor"
     type: "sensor"
@@ -329,6 +385,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 50
+    refresh_unit: "m"
+
   - name: "Tampon Haut"
     unique_id: "tampon_haut_sensor"
     type: "sensor"
@@ -345,6 +404,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
+
   - name: "Tampon Bas"
     unique_id: "tampon_bas_sensor"
     type: "sensor"
@@ -361,6 +423,26 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 1
+    refresh_unit: "m"
+
+  - name: "Stock energie"
+    unique_id: "stock_energie_sensor"
+    type: "sensor"
+    device_class: "energy"
+    state_class: "measurement"
+    icon: "mdi:flash"
+    unit_of_measurement: "kWh"
+    state_topic: "froling/S3Turbo/STOCK_ENERGIE/state"
+    input_type: "computed"
+    formula: "buffer_energy_kwh"
+    sources:
+      - "tampon_haut_sensor"
+      - "tampon_bas_sensor"
+    precision: 2
+    refresh: 1
+    refresh_unit: "m"
+
   - name: "T° depart chauffage"
     unique_id: "temperature_depart_chauffage_sensor"
     type: "sensor"
@@ -377,6 +459,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "s"
+
   - name: "Charge tampon"
     unique_id: "charge_tampon_sensor"
     type: "sensor"
@@ -392,6 +477,27 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 10
+    refresh_unit: "m"
+
+  - name: "pompe accumulateur"
+    unique_id: "pompe_accu"
+    type: "sensor"
+    device_class: "battery"
+    state_class: "measurement"
+    icon: "mdi:percent-circle-outline"
+    unit_of_measurement: "%"
+    state_topic: "froling/S3Turbo/pompe_accu/state"
+    value_template: "{{ value_json.pompe_accu }}"
+    input_type: "input_register"
+    address: 30141
+    offset: 30001
+    precision: 0
+    value_map: null
+    signed: false
+    refresh: 2
+    refresh_unit: "s"
+
 #   Digital Outputs
 # Function: Read Coil Status (FC=01)
   - name: pompe circuit_chauffage
@@ -406,6 +512,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 2
+    refresh_unit: "s"
+
   - name: cc_melangeur_ouvert
     unique_id: "cc_melangeur_ouvert"
     type: "binary_sensor"
@@ -418,6 +527,9 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 2
+    refresh_unit: "s"
+
   - name: cc_melangeur_ferme
     unique_id: "cc_melangeur_ferme"
     type: "binary_sensor"
@@ -430,6 +542,6 @@ entities:
     precision: 0
     value_map: null
     signed: false
+    refresh: 2
+    refresh_unit: "s"
  
-
-
diff --git a/src/config/config.yaml b/src/config/config.yaml.old
similarity index 100%
rename from src/config/config.yaml
rename to src/config/config.yaml.old
diff --git a/src/main.py b/src/main.py
index 2114ca5..dc5d4ec 100755
--- a/src/main.py
+++ b/src/main.py
@@ -1,7 +1,8 @@
 import os
 import time
 import yaml
-import json 
+import json
+import logging
 import paho.mqtt.client as mqtt
 from pyModbusTCP.client import ModbusClient
 
@@ -46,8 +47,98 @@ def load_config():
         config = yaml.safe_load(file)
     return config
 
+def setup_logging(level_name, log_file=None):
+    level = getattr(logging, str(level_name).upper(), logging.INFO)
+    logger = logging.getLogger("modbus2mqtt")
+    logger.setLevel(level)
+    if not logger.handlers:
+        formatter = logging.Formatter("%(asctime)s %(levelname)s %(message)s")
+        console_handler = logging.StreamHandler()
+        console_handler.setFormatter(formatter)
+        logger.addHandler(console_handler)
+        if log_file:
+            file_handler = logging.FileHandler(log_file)
+            file_handler.setFormatter(formatter)
+            logger.addHandler(file_handler)
+    return logger
+
+def get_entity_refresh_seconds(entity, default_seconds):
+    """
+    Return refresh interval in seconds for an entity.
+    Accepts per-entity "refresh" with "refresh_unit" ("s" or "m").
+    Falls back to default_seconds when missing or invalid.
+    """
+    refresh_value = entity.get('refresh')
+    if refresh_value is None:
+        return default_seconds
+    try:
+        refresh_value = float(refresh_value)
+    except (TypeError, ValueError):
+        return default_seconds
+    if refresh_value <= 0:
+        return default_seconds
+    unit = str(entity.get('refresh_unit', 's')).lower()
+    if unit in ('m', 'min', 'minute', 'minutes'):
+        return refresh_value * 60
+    return refresh_value
+
+def get_entity_interval_seconds(entity, default_seconds, error_count, error_backoff_max):
+    base_interval = get_entity_refresh_seconds(entity, default_seconds)
+    if error_count <= 0:
+        return base_interval
+    backoff = base_interval * (2 ** min(error_count, 5))
+    if backoff > error_backoff_max:
+        backoff = error_backoff_max
+    return backoff
+
+def get_state_topic(entity, config):
+    return entity.get('state_topic') or f"{config['mqtt']['topic_prefix']}/{entity['name']}/state"
+
+def apply_value_map(value, entity, config, logger):
+    map_name = entity.get('value_map')
+    if not map_name:
+        return value
+    value_maps = config.get('value_maps', {})
+    mapping = value_maps.get(map_name)
+    if mapping is None:
+        logger.error("Value map not found: %s", map_name)
+        return value
+    return mapping.get(value, value)
+
+def compute_buffer_energy_kwh(avg_temp_c, volume_l, min_temp_c):
+    if avg_temp_c <= min_temp_c:
+        return 0.0
+    delta = avg_temp_c - min_temp_c
+    # 1L water ~ 1kg, 4.186 kJ/kgK => kWh = kJ / 3600
+    return (volume_l * delta * 4.186) / 3600.0
+
+def validate_config(config, logger):
+    required_top = ['mqtt', 'modbus', 'homeassistant', 'entities']
+    for key in required_top:
+        if key not in config:
+            raise ValueError(f"Missing config section: {key}")
+    seen_ids = set()
+    valid_types = {'input_register', 'holding_register', 'input_status', 'coil', 'computed'}
+    for entity in config['entities']:
+        for field in ['name', 'unique_id', 'input_type']:
+            if field not in entity:
+                raise ValueError(f"Missing entity field: {field}")
+        if entity['input_type'] != 'computed':
+            for field in ['address', 'offset']:
+                if field not in entity:
+                    raise ValueError(f"Missing entity field: {field}")
+        else:
+            if 'formula' not in entity or 'sources' not in entity:
+                raise ValueError(f"Missing computed entity fields: {entity['unique_id']}")
+        if entity['unique_id'] in seen_ids:
+            raise ValueError(f"Duplicate unique_id: {entity['unique_id']}")
+        seen_ids.add(entity['unique_id'])
+        if entity['input_type'] not in valid_types:
+            raise ValueError(f"Invalid input_type: {entity['input_type']}")
+    logger.info("Configuration validated (%d entities).", len(config['entities']))
+
 # Ajout de la fonction de publication des messages de découverte
-def publish_discovery_messages(client, config):
+def publish_discovery_messages(client, config, logger):
     base_topic = config['homeassistant']['discovery_prefix']
     node_id = config['homeassistant']['node_id']
     device_info = config['device']
@@ -62,12 +153,10 @@ def publish_discovery_messages(client, config):
             "unique_id": entity['unique_id'],
             "device": device_info,
             "name": entity['name'],
-            "state_topic": f"{config['mqtt']['topic_prefix']}/{entity['name']}/state",
+            "state_topic": get_state_topic(entity, config),
             #"value_template": "{{ value }}",  # Ajouter une value_template si nécessaire
             #"device_class": entity.get('device_class', ''),
             #"unit_of_measurement": entity.get('unit_of_measurement', '')# La valeur par défaut est '°C
-          
-            
         }
         if "unit_of_measurement" in entity: message["unit_of_measurement"] = entity["unit_of_measurement"]
         if "state_class" in entity: message["state_class"] = entity["state_class"]
@@ -80,10 +169,12 @@ def publish_discovery_messages(client, config):
                 "value_template": entity.get('value_template', "{{ value_json.value }}"),  # Ajouter une value_template si nécessaire
             })
         client.publish(discovery_topic, json.dumps(message), qos=1, retain=True)
+        logger.info("HA discovery published: %s", discovery_topic)
 
-def publish_availability(client, status, config):
+def publish_availability(client, status, config, logger):
     availability_topic = f"{config['mqtt']['topic_prefix']}/availability"
     client.publish(availability_topic, status, qos=1, retain=True)
+    logger.info("Availability set to %s", status)
 
 def convert_to_signed(value):
     NEGATIVE_THRESHOLD = 32000  # Seuil pour déterminer les valeurs négatives
@@ -96,23 +187,30 @@ def convert_to_signed(value):
 
 def on_connect(client, userdata, flags, rc):
     if rc == 0:
-        print("Connected to MQTT Broker!")
-        publish_availability(client, 'online', userdata)
+        logger = userdata.get('_logger')
+        if logger:
+            logger.info("Connected to MQTT broker")
+        publish_availability(client, 'online', userdata, logger)
         # Si l'autodiscovery est activé, publiez les messages de découverte
         if userdata['homeassistant']['autodiscovery']:
-            publish_discovery_messages(client, userdata)
+            publish_discovery_messages(client, userdata, logger)
     else:
-        print("Failed to connect, return code %d\n", rc)
+        logger = userdata.get('_logger')
+        if logger:
+            logger.error("Failed to connect to MQTT broker (rc=%d)", rc)
 
 def on_publish(client, userdata, result):
-    print(f"Data published to MQTT. Result: {result}")
+    logger = userdata.get('_logger')
+    if logger:
+        logger.debug("MQTT publish result: %s", result)
 
 
-def connect_modbus(host, port, unit_id, timeout):
+def connect_modbus(host, port, unit_id, timeout, logger, client=None):
     """
     Connect to the Modbus server.
     """
-    client = ModbusClient()
+    if client is None:
+        client = ModbusClient()
     client.host = host  # Set the host
     client.port = port  # Set the port
     client.unit_id = unit_id
@@ -120,13 +218,13 @@ def connect_modbus(host, port, unit_id, timeout):
     connection = client.open()
 
     if connection:
-        print(f"Connected to Modbus server at {host}:{port}")
+        logger.info("Connected to Modbus server at %s:%s", host, port)
     else:
-        print(f"Failed to connect to Modbus server at {host}:{port}")
+        logger.error("Failed to connect to Modbus server at %s:%s", host, port)
 
-    return client
+    return client if connection else None
 
-def read_modbus_registers(client, input_type, address, offset, scale=1, precision=0, count=1):
+def read_modbus_registers(client, input_type, address, offset, scale=1, precision=0, count=1, logger=None):
     """
     Read registers from the Modbus server.
     
@@ -140,57 +238,215 @@ def read_modbus_registers(client, input_type, address, offset, scale=1, precisio
     :param value_map: a dictionary mapping register values to human-readable strings
     :return: the scaled and rounded value of the registers or None if an error occurs
     """
-    print(f"Address from call: {address}, Offset from call: {offset}")
     # Calculate the real address by subtracting the offset
     real_address = address - offset
-    print(f"Preparing to read Modbus registers with initial address: {address}, "
-          f"offset: {offset}, resulting in real address: {real_address}")
+    if logger:
+        logger.info(
+            "Modbus read: type=%s address=%s offset=%s real=%s count=%s",
+            input_type,
+            address,
+            offset,
+            real_address,
+            count,
+        )
     try:
         regs = None
         if input_type == 'input_register':
             # Use FC04 to read input registers
-            print(f"Reading {count} input register(s) starting at initial address {address} "
-                  f"(real address {real_address}, offset {offset}) using FC04")
             regs = client.read_input_registers(real_address, count)
         elif input_type == 'holding_register':
             # Use FC03 to read holding registers
-            print(f"Reading {count} holding register(s) starting at initial address {address} "
-                  f"(real address {real_address}, offset {offset}) using FC03")
             regs = client.read_holding_registers(real_address, count)
         elif input_type == 'input_status':
             # Use FC02 to read discrete inputs
-            print(f"Reading {count} input status(es) starting at initial address {address} "
-                  f"(real address {real_address}, offset {offset}) using FC02")
             regs = client.read_discrete_inputs(real_address, count)
         elif input_type == 'coil':
             # Use FC01 to read coils
-            print(f"Reading {count} coil(s) starting at initial address {address} "
-                  f"(real address {real_address}, offset {offset}) using FC01")
             regs = client.read_coils(real_address, count)
         else:
-            print(f"Invalid input type: {input_type}")
+            if logger:
+                logger.error("Invalid input type: %s", input_type)
             return None
 
         if regs is not None:
             
             # Apply scaling and rounding to the read values
             scaled_and_rounded_regs = [round(reg * scale, precision) for reg in regs]
-            print(f"Read successful: {scaled_and_rounded_regs}")
+            if logger:
+                logger.info("Modbus read success: %s", scaled_and_rounded_regs)
             return scaled_and_rounded_regs
         else:
-            print(f"Read error at initial address {address} (real address {real_address}, offset {offset})")
+            if logger:
+                logger.error(
+                    "Modbus read error at address=%s (real=%s offset=%s)",
+                    address,
+                    real_address,
+                    offset,
+                )
             return None
     except Exception as e:
-        print(f"Modbus read error at initial address {address} (real address {real_address}, offset {offset}): {e}")
+        if logger:
+            logger.exception(
+                "Modbus read exception at address=%s (real=%s offset=%s): %s",
+                address,
+                real_address,
+                offset,
+                e,
+            )
         return None
 
+def read_modbus_raw(client, input_type, real_address, count, logger=None):
+    if logger:
+        logger.info(
+            "Modbus batch read: type=%s start=%s count=%s",
+            input_type,
+            real_address,
+            count,
+        )
+    try:
+        if input_type == 'input_register':
+            return client.read_input_registers(real_address, count)
+        if input_type == 'holding_register':
+            return client.read_holding_registers(real_address, count)
+        if input_type == 'input_status':
+            return client.read_discrete_inputs(real_address, count)
+        if input_type == 'coil':
+            return client.read_coils(real_address, count)
+    except Exception as e:
+        if logger:
+            logger.exception(
+                "Modbus batch exception at start=%s count=%s: %s",
+                real_address,
+                count,
+                e,
+            )
+        return None
+    if logger:
+        logger.error("Invalid input type for batch read: %s", input_type)
+    return None
+
+def _process_batch(
+    modbus_client,
+    input_type,
+    batch,
+    now,
+    logger,
+    mqtt_client,
+    config,
+    last_read_at,
+    error_counts,
+    last_values,
+    publish_on_change_only,
+    metrics,
+):
+    start_address = batch[0][0]
+    end_address = batch[-1][0]
+    count = end_address - start_address + 1
+    regs = read_modbus_raw(modbus_client, input_type, start_address, count, logger=logger)
+    if regs is None:
+        for _, entity in batch:
+            uid = entity['unique_id']
+            error_counts[uid] = error_counts.get(uid, 0) + 1
+            last_read_at[uid] = now
+            metrics['errors'] += 1
+        return
+
+    for real_address, entity in batch:
+        uid = entity['unique_id']
+        idx = real_address - start_address
+        if idx < 0 or idx >= len(regs):
+            logger.error("Batch index out of range for %s", entity['name'])
+            error_counts[uid] = error_counts.get(uid, 0) + 1
+            last_read_at[uid] = now
+            metrics['errors'] += 1
+            continue
+
+        value = regs[idx]
+        scale = entity.get('scale', 1)
+        precision = entity.get('precision', 0)
+        value = round(value * scale, precision)
+        if entity.get('signed', False):
+            value = convert_to_signed(value)
+            logger.info("Signed conversion: %s", value)
+        value = apply_value_map(value, entity, config, logger)
+        metrics['reads'] += 1
+
+        previous_value = last_values.get(uid)
+        last_values[uid] = value
+        if publish_on_change_only and previous_value == value:
+            logger.debug("Unchanged value for %s, skip publish", entity['name'])
+            last_read_at[uid] = now
+            error_counts[uid] = 0
+            continue
+
+        topic = get_state_topic(entity, config)
+        mqtt_client.publish(topic, value)
+        logger.info("MQTT publish: %s => %s", topic, value)
+        last_read_at[uid] = now
+        error_counts[uid] = 0
+        metrics['published'] += 1
+
+def _process_computed(
+    entity,
+    now,
+    logger,
+    mqtt_client,
+    config,
+    last_read_at,
+    last_values,
+    publish_on_change_only,
+    metrics,
+):
+    sources = entity.get('sources', [])
+    source_values = []
+    for source_id in sources:
+        if source_id not in last_values:
+            logger.debug("Computed %s missing source %s", entity['name'], source_id)
+            return
+        source_values.append(last_values[source_id])
+
+    if entity.get('formula') == 'buffer_energy_kwh':
+        volume_l = float(config.get('buffer_volume_l', 1000))
+        min_temp_c = float(config.get('buffer_min_temp_c', 25))
+        avg_temp_c = sum(source_values) / len(source_values)
+        value = compute_buffer_energy_kwh(avg_temp_c, volume_l, min_temp_c)
+    else:
+        logger.error("Unknown formula for %s", entity['name'])
+        return
+
+    precision = entity.get('precision', 2)
+    value = round(value, precision)
+    metrics['reads'] += 1
+
+    previous_value = last_values.get(entity['unique_id'])
+    last_values[entity['unique_id']] = value
+    if publish_on_change_only and previous_value == value:
+        logger.debug("Unchanged value for %s, skip publish", entity['name'])
+        last_read_at[entity['unique_id']] = now
+        return
+
+    topic = get_state_topic(entity, config)
+    mqtt_client.publish(topic, value)
+    logger.info("MQTT publish: %s => %s", topic, value)
+    last_read_at[entity['unique_id']] = now
+    metrics['published'] += 1
+
 
 
 
 def main():
     config = load_config()
+    logger = setup_logging(config.get('log_level', 'INFO'), config.get('log_file'))
+    config['_logger'] = logger
+    validate_config(config, logger)
 
     refresh_rate = config['refresh_rate']   # Obtenez la fréquence d'actualisation depuis la configuration
+    default_refresh_seconds = float(refresh_rate)
+    error_backoff_max = float(config.get('error_backoff_max', 300))
+    metrics_interval = float(config.get('metrics_interval', 60))
+    metrics_topic = f"{config['mqtt']['topic_prefix']}/metrics"
+    start_time = time.monotonic()
+    next_metrics_at = time.monotonic() + metrics_interval
 
  # Configuration MQTT
     mqtt_config = config['mqtt']
@@ -200,11 +456,20 @@ def main():
     mqtt_client.on_publish = on_publish
     if mqtt_config['user'] and mqtt_config['password']:
         mqtt_client.username_pw_set(mqtt_config['user'], mqtt_config['password'])
+    availability_topic = f"{config['mqtt']['topic_prefix']}/availability"
+    mqtt_client.will_set(availability_topic, 'offline', qos=1, retain=True)
     mqtt_client.connect(mqtt_config['host'], mqtt_config['port'], 60)
     mqtt_client.loop_start()
 
+    last_read_at = {}
+    error_counts = {}
+    last_values = {}
+    metrics = {"reads": 0, "errors": 0, "published": 0}
+    modbus_client = None
+    reconnect_delay = float(config.get('modbus', {}).get('reconnect_min', 1))
+    reconnect_max = float(config.get('modbus', {}).get('reconnect_max', 30))
+    publish_on_change_only = bool(config.get('publish_on_change_only', True))
     while True:
-        modbus_client = None
         try:
         # etape de connexion Modbus
         # Affichage de la configuration pour la vérification
@@ -226,53 +491,157 @@ def main():
 
 
         # Étape de connexion Modbus
-            modbus_client = connect_modbus(config['modbus']['host'],
-                                           config['modbus']['port'],
-                                           config['modbus']['unit_id'],
-                                           config['modbus']['timeout'])
+            if modbus_client is None:
+                modbus_client = connect_modbus(
+                    config['modbus']['host'],
+                    config['modbus']['port'],
+                    config['modbus']['unit_id'],
+                    config['modbus']['timeout'],
+                    logger,
+                )
+                if modbus_client is None:
+                    logger.warning("Modbus reconnect in %.1fs", reconnect_delay)
+                    time.sleep(reconnect_delay)
+                    reconnect_delay = min(reconnect_delay * 2, reconnect_max)
+                    continue
+                reconnect_delay = float(config.get('modbus', {}).get('reconnect_min', 1))
+            elif not modbus_client.open():
+                logger.error("Failed to reconnect to the Modbus server.")
+                modbus_client = None
+                logger.warning("Modbus reconnect in %.1fs", reconnect_delay)
+                time.sleep(reconnect_delay)
+                reconnect_delay = min(reconnect_delay * 2, reconnect_max)
+                continue
             if modbus_client:
                 # Lecture des registres Modbus pour chaque entité
+                now = time.monotonic()
+                due_entities = []
+                due_computed = []
                 for entity in config['entities']:
-                    input_type = entity['input_type']
-                    address = entity['address']
-                    offset = entity['offset']  # Utilisation de l'offset de l'entité
-                    scale = entity.get('scale', 1)
-                    precision = entity.get('precision', 0)  # Utilisation de get pour une valeur par défaut si non présente
-                    count = 1  # Supposons que count est toujours 1 pour simplifier, à ajuster si nécessaire
-            
-                    # Affichage de l'entité et de l'offset avant la lecture
-                    print(f"Reading entity: {entity['name']} with offset: {offset}")
-                    # Lecture des registres avec l'offset correct
-                    regs = read_modbus_registers(modbus_client, input_type, address, offset, scale, precision, count)
-                    if regs is not None:
-                        
-                        value = regs[0]  # Prend la première valeur si plusieurs registres sont lus
-                        if entity.get('signed', False):
-                            value = convert_to_signed(value)
-                            print(f"Valeur convertie en signée: {value}")
-
-                        # Publier la valeur lue sur le topic MQTT approprié
-                        topic = f"{config['mqtt']['topic_prefix']}/{entity['name']}/state"
-                        mqtt_client.publish(topic, value)
-                        print(f"Published value for {entity['name']}: {value}")
+                    uid = entity['unique_id']
+                    error_count = error_counts.get(uid, 0)
+                    interval_seconds = get_entity_interval_seconds(
+                        entity,
+                        default_refresh_seconds,
+                        error_count,
+                        error_backoff_max,
+                    )
+                    last_ts = last_read_at.get(uid, 0)
+                    if now - last_ts < interval_seconds:
+                        logger.debug(
+                            "Skip entity %s (next in %.1fs)",
+                            entity['name'],
+                            interval_seconds - (now - last_ts),
+                        )
+                        continue
+                    if entity['input_type'] == 'computed':
+                        due_computed.append(entity)
                     else:
-                        print(f"Failed to read value for {entity['name']}")
-                       
-                # Assurez-vous de fermer la connexion Modbus lorsque vous avez terminé
-                modbus_client.close()
-            else:
-                print("Failed to connect to the Modbus server.")
+                        due_entities.append(entity)
+
+                grouped = {}
+                for entity in due_entities:
+                    real_address = entity['address'] - entity['offset']
+                    key = entity['input_type']
+                    grouped.setdefault(key, []).append((real_address, entity))
+
+                for input_type, items in grouped.items():
+                    items.sort(key=lambda x: x[0])
+                    batch = []
+                    prev_addr = None
+                    for real_address, entity in items:
+                        if prev_addr is None or real_address == prev_addr + 1:
+                            batch.append((real_address, entity))
+                        else:
+                            _process_batch(
+                                modbus_client,
+                                input_type,
+                                batch,
+                                now,
+                                logger,
+                                mqtt_client,
+                            config,
+                            last_read_at,
+                            error_counts,
+                            last_values,
+                            publish_on_change_only,
+                            metrics,
+                        )
+                            batch = [(real_address, entity)]
+                        prev_addr = real_address
+                    if batch:
+                        _process_batch(
+                            modbus_client,
+                            input_type,
+                            batch,
+                            now,
+                            logger,
+                            mqtt_client,
+                            config,
+                            last_read_at,
+                            error_counts,
+                            last_values,
+                            publish_on_change_only,
+                            metrics,
+                        )
+                for entity in due_computed:
+                    _process_computed(
+                        entity,
+                        now,
+                        logger,
+                        mqtt_client,
+                        config,
+                        last_read_at,
+                        last_values,
+                        publish_on_change_only,
+                        metrics,
+                    )
+
+                # Calcule le prochain delai selon les entites
+                now = time.monotonic()
+                if now >= next_metrics_at:
+                    payload = {
+                        "reads": metrics["reads"],
+                        "errors": metrics["errors"],
+                        "published": metrics["published"],
+                        "entities": len(config['entities']),
+                        "uptime_s": int(now - start_time),
+                    }
+                    mqtt_client.publish(metrics_topic, json.dumps(payload))
+                    logger.info("MQTT metrics: %s", payload)
+                    next_metrics_at = now + metrics_interval
+                next_sleep = None
+                for entity in config['entities']:
+                    uid = entity['unique_id']
+                    error_count = error_counts.get(uid, 0)
+                    interval_seconds = get_entity_interval_seconds(
+                        entity,
+                        default_refresh_seconds,
+                        error_count,
+                        error_backoff_max,
+                    )
+                    last_ts = last_read_at.get(entity['unique_id'], 0)
+                    due_in = interval_seconds - (now - last_ts)
+                    if due_in < 0:
+                        due_in = 0
+                    if next_sleep is None or due_in < next_sleep:
+                        next_sleep = due_in
+                if next_sleep is None:
+                    next_sleep = default_refresh_seconds
+                if next_sleep < 0.1:
+                    next_sleep = 0.1
+                logger.info("Sleeping for %.1fs until next due entity.", next_sleep)
+                time.sleep(next_sleep)
+                continue
                 
         except Exception as e:
-            print(f"An error occurred: {e}")
-            publish_availability(mqtt_client, 'offline', config)
-        finally:
+            logger.exception("An error occurred: %s", e)
+            publish_availability(mqtt_client, 'offline', config, logger)
             if modbus_client:
                 modbus_client.close()
+                modbus_client = None
                 
-        # Attendez la fréquence d'actualisation avant de recommencer
-        print(f"Waiting for {refresh_rate} seconds before the next update.")
-        time.sleep(refresh_rate)
+        time.sleep(default_refresh_seconds)
 
 if __name__ == '__main__':
     main()