feat: finalize documentation and validation (Task 7)

- Rewrite project CLAUDE.md to match actual C/Unity implementation and modules
- Add docs/hardware_connection_diagram.md (ESP32-C6 <-> Ballu AC wiring)
- Add docs/home_assistant_integration.md (HA usage examples)
- Update Readme.md doc index and fix unclosed code fence
- Validate docs against implementation (build + all tests pass)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Claude.md

@@ -3,36 +3,61 @@
 This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
 
 ## Common Development Commands
-1. **Build**: `make build` - Compiles firmware for ESP32-C6
+The project is plain C compiled with `gcc` and tested with the vendored Unity
-2. **Upload**: `make upload` - Flashes firmware to device (requires USB connection)
+framework (see `Makefile`). There is no ESP-IDF dependency for the host build/test
-3. **Test**: `make test` - Runs all unit/integration tests using Vitest
+flow; the firmware entry point in `src/main.c` is excluded from test binaries via
-4. **Single Test**: `make test TEST_NAME="test_module_name"` - Runs specific test
+the `UNIT_TEST` define.
-5. **Debug**: `make debug` - Starts debug mode with serial console
+
+1. **Build (host)**: `make build` - Compiles all `src/*.c` into `build/app`
+2. **Run all tests**: `make test` - Builds and runs every Unity test suite
+3. **Single Test**: `make test-<module>` - e.g. `make test-app-controller`,
+   `make test-midea-protocol`, `make test-uart`, `make test-zigbee-zcl`,
+   `make test-integration-layer`, `make test-status-monitor`
+4. **Clean**: `make clean` - Removes `build/` and compiled test binaries
+5. **Help**: `make help` - Lists all available targets
+
+> Note: `make upload`/`make debug` (flashing to real ESP32-C6 hardware) are
+> hardware steps performed with the ESP-IDF toolchain and are not part of the
+> host test flow.
 
 ## Code Architecture
-The system implements a layered architecture for AC controller control:
+The system implements a layered architecture, top to bottom. Each layer is a
+`src/<name>.c` + `<name>.h` pair with a matching `test/<name>_test.c` suite:
 
-1. **Zigbee Interface Module**
+1. **Application Controller** (`app_controller.c/h`, entry: `main.c`)
-   - Receives and decodes Zigbee messages from Home Assistant or similar
+   - Owns every subsystem and wires the two end-to-end data flows.
-   - Translates commands to UART format
+   - Command path: HA → Zigbee → Integration → UART → AC.
-   - Key files: `zigbee-handler.c`, `zigbee-decoder.h`
+   - Feedback path: AC → UART → Status → Integration → Zigbee → HA.
+   - Provides reset/recovery, health check, and the firmware service loop.
 
-2. **Command Processing Core**
+2. **Integration Layer** (`integration_layer.c/h`)
-   - Implements MideaUART protocol (based on cloned MideaUART repository)
+   - Bridges Zigbee ZCL and MideaUART: maps `system_mode` ↔ MideaUART modes,
-   - Parses UART commands and converts to AC control signals
+     converts temperatures, enforces 50ms command spacing / rate limiting.
-   - Key files: `uart-controller.c`, `midea-parser.h`
 
-3. **Hardware Abstraction Layer**
+3. **Zigbee ZCL Cluster** (`zigbee_zcl.c/h`)
-   - Manages ESP32-C6 GPIO and UART operations
+   - ZCL Thermostat cluster server: `local_temperature`, `system_mode`, and
-   - Handles precise timing for AC communication protocol
+     weekly schedule command handling.
-   - Key files: `hardware-abstraction.c`
+
+4. **Status Monitor** (`status_monitor.c/h`)
+   - Periodic AC status polling, ZCL attribute mapping, fault detection
+     (`error_code` / `alarm_mask`), and the communication watchdog.
+
+5. **MideaUART Protocol** (`midea_protocol.c/h`)
+   - `midea_control_t` / `midea_status_t` structures and encode/decode of AC
+     frames; timing helpers (50ms command spacing).
+
+6. **UART Driver** (`uart_driver.c/h`)
+   - Hardware abstraction for ESP32-C6 UART: init at 9600 baud 8N1,
+     send/receive with timeout handling.
 
 ## Development Notes
-- Protocol implementation must strictly follow MideaUART specifications
+- Protocol implementation must strictly follow MideaUART specifications.
-- UART communication requires 50ms baud rate timing
+- UART runs at 9600 baud 8N1; MideaUART commands are spaced at least 50ms apart
-- Testing should focus on edge cases for time-sensitive operations
+  (`command_spacing_ms`, default 50 in `app_controller`/`integration_layer`).
-- Dependencies managed via Makefile - do not modify directly
+- Testing should focus on edge cases for time-sensitive operations.
-- MideaUART implementation: https://github.com/dudanov/MideaUART
+- Tests link every `src/*.c` together, so exactly one `main()` may exist per test
+  binary — the firmware `main()` in `src/main.c` is guarded by `#ifndef UNIT_TEST`.
+- MideaUART reference implementation: https://github.com/dudanov/MideaUART
 
 ## Zigbee ZCL HVAC Integration (Thermostat Cluster)
 
@@ -49,14 +74,19 @@ The system implements a layered architecture for AC controller control:
   - `EZB_ZCL_HVAC_SYSTEM_TYPE_CONFIGURATION_COOLING_SYSTEM_STAGE = 0x03`
 
 ### 3. Temperature Control
-- Temperature range: -1°C to 32767°C (0.01°C resolution)
+- ZCL `local_temperature` / target temperature are in 0.01°C units (int16_t).
-- Convert to MideaUART format: divide by 100 (e.g., 2500 → 25.0°C)
+- MideaUART `target_temp` is also stored in 0.01°C units (`* 100`), so the
-- Command structure:
+  integration layer passes the value through (see
+  `integration_layer_convert_zcl_temperature`).
+- The MideaUART setter takes Celsius as a float:
+  `midea_control_set_temperature(&control, 25.0f)` for a 25°C target.
+- Command structure (actual C API):
   ```c
-  control.mode = MODE_COOL;      // Zigbee mode: 0x03 (Cooling)
+  midea_control_t control;
-  control.targetTemp = 25.0f;    // 25°C target
+  midea_control_init(&control);
-  control.modeChange = true;
+  midea_control_set_mode(&control, MODE_COOL);   // MideaUART cool mode
-  ac.control(control);
+  midea_control_set_temperature(&control, 25.0f);// 25°C target
+  integration_layer_send_midea_command(&layer, &control);
   ```
 
 ### 4. Schedule Management
@@ -68,14 +98,37 @@ The system implements a layered architecture for AC controller control:
 - Track `ACErrorCode` for system fault detection
 - Implement status callbacks for UI updates
 
-### 6. Mapping Example
+### 6. Mode Mapping (ZCL ↔ MideaUART)
+ZCL `system_mode` and MideaUART `midea_mode_t` use different numeric values; the
+integration layer translates between them
+(`integration_layer_map_zcl_to_midea_mode` / `integration_layer_map_midea_to_zcl_mode`):
+
+| ZCL system_mode | MideaUART midea_mode_t |
+| :-- | :-- |
+| 0 Off | MODE_OFF (0) |
+| 1 Auto | MODE_AUTO (3) |
+| 3 Cool | MODE_COOL (1) |
+| 4 Heat | MODE_HEAT (2) |
+
+`midea_mode_t` additionally defines MODE_DRY (4), MODE_FAN (5), MODE_SLEEP (6),
+MODE_TURBO (7). See `src/midea_protocol.h` for the authoritative enum.
+
+### 7. Mapping Example (feedback path)
 ```c
-// When Zigbee reports mode = 0x03 (Cooling) and target temp = 2500 (25.00°C)
+// An AC status frame decoded to midea_status_t is mapped to ZCL attributes
-Control control;
+// and pushed into the cluster for Home Assistant to read:
-control.mode = MODE_COOL;
+zcl_thermostat_attrs_t attrs;
-control.targetTemp = 25.0f; // Convert from 0.01°C units
+status_monitor_map_to_zcl(&status, &attrs);
-control.modeChange = true;
+zigbee_zcl_set_local_temperature(attrs.local_temperature);
-ac.control(control);
+zigbee_zcl_set_system_mode(attrs.system_mode);
 ```
 
 This documentation covers both the core Midea UART protocol for device communication and the Zigbee ZCL thermostat cluster integration for smart home control.
+
+## Additional Documentation
+- `docs/protocol.md` — MideaUART protocol details
+- `docs/zcl_hvac.md` — Zigbee ZCL Thermostat cluster details
+- `docs/hardware_connection_diagram.md` — ESP32-C6 ↔ Ballu AC wiring diagram
+- `docs/home_assistant_integration.md` — Home Assistant usage examples
+- `docs/Hardware integration guide.md` — ESP32-C6 hardware integration (RU)
+- `docs/Build system details.md` — Build system and dependencies

Readme.md

@@ -36,10 +36,22 @@ test/
   app_controller_test.c       - End-to-end integration tests (full command cycles)
 
 docs/
-  protocol.md                 - MideaUART protocol details
+  protocol.md                    - MideaUART protocol details
-  zcl_hvac.md                 - Zigbee ZCL Thermostat cluster details
+  zcl_hvac.md                    - Zigbee ZCL Thermostat cluster details
-  Hardware integration guide.md - Hardware connection information
+  hardware_connection_diagram.md - ESP32-C6 <-> Ballu AC wiring diagram
-  Build system details.md     - Build system and dependencies
+  home_assistant_integration.md  - Home Assistant usage examples
+  Hardware integration guide.md  - ESP32-C6 hardware integration (RU)
+  Build system details.md        - Build system and dependencies
+```
+
+## Documentation
+
+- [MideaUART protocol](docs/protocol.md)
+- [Zigbee ZCL Thermostat cluster](docs/zcl_hvac.md)
+- [Hardware connection diagram](docs/hardware_connection_diagram.md)
+- [Home Assistant integration guide](docs/home_assistant_integration.md)
+- [ESP32-C6 hardware integration guide](docs/Hardware%20integration%20guide.md)
+- [Build system details](docs/Build%20system%20details.md)
 
 ## Getting Started
 

docs/hardware_connection_diagram.md

@@ -0,0 +1,98 @@
+# Hardware Connection Diagram: ESP32-C6 ↔ Ballu AC
+
+This document describes the physical wiring between the ESP32-C6 controller and
+the Ballu air conditioner's MideaUART port, and the logical signal path through
+the firmware.
+
+> Pin numbers below match the firmware defaults in `src/app_controller.c`
+> (`apply_default_uart_config`): **TX = GPIO16**, **RX = GPIO17**, 9600 baud, 8N1.
+> These are configurable via `app_controller_config_t.uart_config`.
+
+## 1. Signal Overview
+
+```
++---------------------+        UART 9600 8N1        +---------------------+
+|                     |   (50 ms command spacing)   |                     |
+|   Home Assistant    |                             |     Ballu AC unit   |
+|   (Zigbee coord.)   |                             |   (Midea UART bus)  |
+|                     |                             |                     |
++----------+----------+                             +----------+----------+
+           |                                                   |
+    Zigbee 2.4 GHz (802.15.4)                          3.3V TTL UART
+           |                                                   |
++----------v---------------------------------------------------v----------+
+|                          ESP32-C6 controller                            |
+|                                                                         |
+|  [Zigbee radio] --> zigbee_zcl --> integration_layer --> midea_protocol |
+|                                          |                    |         |
+|                                          v                    v         |
+|                                   status_monitor  <-->   uart_driver    |
+|                                                              |          |
+|                                          GPIO16 (TX) --------+          |
+|                                          GPIO17 (RX) --------+          |
++-------------------------------------------------------------------------+
+```
+
+## 2. Physical Wiring (ESP32-C6 ↔ AC MideaUART header)
+
+The Ballu/Midea indoor unit exposes a 3-wire (or 4-wire) TTL UART header. The AC
+side already provides regulated power on some models; **verify the voltage on the
+AC connector before wiring** — the ESP32-C6 GPIO are strictly 3.3V tolerant.
+
+| ESP32-C6 pin | Direction | AC MideaUART pin | Notes |
+| :-- | :--: | :-- | :-- |
+| GPIO16 (TX)  | ESP → AC | RX  | Controller transmits commands to the AC |
+| GPIO17 (RX)  | AC → ESP | TX  | Controller receives status frames from the AC |
+| GND          | common   | GND | **Mandatory** common ground reference |
+| 3V3          | power    | +5V/+12V | Do **not** connect AC +5V/+12V directly to 3V3; use a suitable regulator if powering the ESP32-C6 from the AC |
+
+```mermaid
+graph LR
+    subgraph AC [Ballu AC - Midea UART header]
+        ARX[RX]
+        ATX[TX]
+        AGND[GND]
+        APWR[+5V / +12V]
+    end
+
+    subgraph ESP [ESP32-C6 controller]
+        ETX[GPIO16 TX]
+        ERX[GPIO17 RX]
+        EGND[GND]
+        E3V3[3V3]
+    end
+
+    ETX -->|3.3V TTL| ARX
+    ATX -->|3.3V TTL| ERX
+    EGND --- AGND
+    APWR -.->|via 3.3V regulator only| E3V3
+```
+
+## 3. Wiring Rules
+
+- **Cross TX/RX**: controller TX (GPIO16) → AC RX; AC TX → controller RX (GPIO17).
+- **Common ground is mandatory** — floating grounds cause framing errors.
+- **3.3V logic only.** If the AC UART header uses 5V logic, insert a logic-level
+  shifter between the boards.
+- **Power isolation.** Never feed the AC's raw supply rail into the ESP32-C6 3V3
+  pin; step it down with a regulator (or power the ESP32-C6 over USB during
+  development).
+- **Strapping pins.** GPIO16/GPIO17 are the ESP32-C6 default UART0 pins used for
+  boot logging/flashing. When wiring the AC to these pins, disconnect the AC
+  during flashing, or remap the AC UART to spare GPIO via
+  `uart_config_t.tx_pin` / `rx_pin` to keep the boot console free.
+
+## 4. Firmware Signal Path
+
+- **Command path (HA → AC):**
+  `zigbee_zcl` receives a ZCL Thermostat command → `integration_layer` maps
+  `system_mode`/temperature to a `midea_control_t` → `midea_protocol` encodes the
+  frame → `uart_driver` transmits it on GPIO16 with ≥50 ms spacing.
+- **Feedback path (AC → HA):**
+  `uart_driver` reads a frame on GPIO17 → `midea_protocol` decodes it to
+  `midea_status_t` → `status_monitor` runs fault detection + watchdog and maps to
+  `zcl_thermostat_attrs_t` → `zigbee_zcl` publishes `local_temperature` and
+  `system_mode` for Home Assistant.
+
+See `docs/Hardware integration guide.md` for detailed ESP32-C6 pinout, strapping
+pin cautions, and PCB layout guidance.

docs/home_assistant_integration.md

@@ -0,0 +1,144 @@
+# Home Assistant Integration Guide
+
+This controller presents the Ballu AC to Home Assistant as a standard Zigbee
+**ZCL Thermostat** device. Home Assistant talks to it through a Zigbee
+coordinator running either ZHA or Zigbee2MQTT — no custom integration is needed
+beyond the device pairing.
+
+## 1. What the Device Exposes
+
+The firmware implements a ZCL Thermostat cluster server
+(`src/zigbee_zcl.c`) with these attributes:
+
+| ZCL attribute | Type | Meaning |
+| :-- | :-- | :-- |
+| `local_temperature` | int16, 0.01°C | Current indoor temperature read from the AC |
+| `system_mode` | uint8 | Operating mode (see mapping below) |
+
+`system_mode` values (as exposed on the Zigbee side):
+
+| Value | Mode |
+| :-- | :-- |
+| 0 | Off |
+| 1 | Auto |
+| 3 | Cool |
+| 4 | Heat |
+
+Internally these map to MideaUART modes via the integration layer
+(`integration_layer_map_zcl_to_midea_mode`); MideaUART additionally supports
+Dry, Fan, Sleep, and Turbo (`src/midea_protocol.h`).
+
+## 2. Pairing
+
+1. Put the Zigbee coordinator into permit-join mode (ZHA: *Add device*;
+   Zigbee2MQTT: *Permit join*).
+2. Power on the ESP32-C6 controller; it joins as a Zigbee end device / router.
+3. The device appears with a Thermostat entity exposing current temperature and
+   a mode selector.
+
+## 3. Home Assistant Climate Entity
+
+Once paired, ZHA/Zigbee2MQTT automatically create a `climate.*` entity backed by
+the Thermostat cluster. Example resulting entity state:
+
+```yaml
+climate.ballu_ac:
+  current_temperature: 24.5      # from local_temperature (2450 * 0.01°C)
+  hvac_mode: cool                # from system_mode = 3
+  temperature: 25.0              # target setpoint
+```
+
+### Setting mode and temperature (Lovelace / service call)
+
+```yaml
+# Turn on cooling at 25°C
+service: climate.set_temperature
+target:
+  entity_id: climate.ballu_ac
+data:
+  hvac_mode: cool
+  temperature: 25
+```
+
+```yaml
+# Switch to heating
+service: climate.set_hvac_mode
+target:
+  entity_id: climate.ballu_ac
+data:
+  hvac_mode: heat
+```
+
+```yaml
+# Turn the unit off
+service: climate.set_hvac_mode
+target:
+  entity_id: climate.ballu_ac
+data:
+  hvac_mode: "off"
+```
+
+## 4. Example Automations
+
+Cool the room when it gets warm:
+
+```yaml
+automation:
+  - alias: "Cool bedroom when hot"
+    trigger:
+      - platform: numeric_state
+        entity_id: climate.ballu_ac
+        attribute: current_temperature
+        above: 27
+    action:
+      - service: climate.set_temperature
+        target:
+          entity_id: climate.ballu_ac
+        data:
+          hvac_mode: cool
+          temperature: 24
+```
+
+Turn the AC off when everyone leaves:
+
+```yaml
+automation:
+  - alias: "AC off when away"
+    trigger:
+      - platform: state
+        entity_id: group.family
+        to: "not_home"
+    action:
+      - service: climate.set_hvac_mode
+        target:
+          entity_id: climate.ballu_ac
+        data:
+          hvac_mode: "off"
+```
+
+## 5. Zigbee2MQTT Notes
+
+If using Zigbee2MQTT, the device publishes to
+`zigbee2mqtt/<friendly_name>` with a JSON payload containing
+`local_temperature` and `system_mode`. Publish a command like:
+
+```json
+{ "system_mode": "cool", "occupied_heating_setpoint": 2500 }
+```
+
+Setpoints in raw ZCL are in 0.01°C units (2500 = 25.0°C), matching the firmware's
+temperature representation.
+
+## 6. Status Reporting & Faults
+
+- The controller polls the AC on a configurable interval (default 5000 ms,
+  `status_monitor_config_t.poll_interval_ms`) and updates `local_temperature` /
+  `system_mode` accordingly.
+- If the AC reports a non-zero `error_code` or `alarm_mask`, the status monitor
+  latches a fault (`status_monitor_has_fault`) and the app controller reports
+  unhealthy (`app_controller_is_healthy`).
+- A communication watchdog triggers automatic reset/recovery
+  (`app_controller_recover_if_needed`) if polling fails repeatedly.
+
+See `docs/zcl_hvac.md` for the full ZCL Thermostat cluster reference and
+`docs/hardware_connection_diagram.md` for wiring.

docs/plans/2026-07-05-ballu-ac-esp32c6-controller-implementation.md

@@ -80,12 +80,12 @@ Implementation of ESP32-C6 based AC controller that bridges Zigbee (Home Assista
 - [x] Update Readme.md
 
 ### Task 7: Documentation and Validation
-- [ ] Update CLAUDE.md with implementation details
+- [x] Update CLAUDE.md with implementation details
-- [ ] Create hardware connection diagram in docs/
+- [x] Create hardware connection diagram in docs/
-- [ ] Add usage examples for Home Assistant integration
+- [x] Add usage examples for Home Assistant integration
-- [ ] Validate all documentation against implementation
+- [x] Validate all documentation against implementation
-- [ ] Final review and cleanup
+- [x] Final review and cleanup
-- [ ] Update Readme.md
+- [x] Update Readme.md
 
 ## Technical Details