# Hardware Integration Guide

This guide explains how to run DReader on real e-ink hardware using the dreader-hal library.

## Quick Start

**On Raspberry Pi:**
```bash
# 1. Clone and setup
git clone https://gitea.tourolle.paris/dtourolle/dreader-application.git
cd dreader-application
python3 -m venv venv
source venv/bin/activate

# 2. Install everything
pip install -e .
./install_hardware_drivers.sh

# 3. Run interactive setup (detects hardware and configures)
sudo python3 setup_rpi.py

# 4. Run DReader (uses hardware_config.json)
python examples/run_on_hardware_config.py
```

## Overview

The DReader application uses a plugin-based Hardware Abstraction Layer (HAL) architecture. You can choose different HAL implementations:

- **PygameDisplayHAL** ([dreader/hal_pygame.py](dreader/hal_pygame.py)) - Desktop testing with pygame window
- **HardwareDisplayHAL** ([dreader/hal_hardware.py](dreader/hal_hardware.py)) - Real e-ink hardware via dreader-hal

### Configuration Files

- **hardware_config.json** - Hardware configuration (display, buttons, sensors)
- **accelerometer_config.json** - Accelerometer calibration for tilt gestures

## Hardware Requirements

### Required Components
- **Raspberry Pi** (or compatible SBC)
- **IT8951 E-ink Display Controller** (1872×1404 resolution)
- **FT5316 Capacitive Touch Panel**

### Optional Components
- **BMA400 Accelerometer** - Auto-rotation based on device orientation
- **PCF8523 RTC** - Timekeeping with battery backup
- **INA219 Power Monitor** - Battery level monitoring

## Software Installation

### 1. Install System Dependencies

On Raspberry Pi:

```bash
# Update package list
sudo apt update

# Install system dependencies
sudo apt install -y python3-dev python3-pip python3-venv
sudo apt install -y i2c-tools python3-smbus

# Enable I2C and SPI interfaces
sudo raspi-config
# Navigate to: Interface Options -> Enable I2C and SPI
```

### 2. Clone and Set Up DReader Application

```bash
# Clone the application
git clone https://gitea.tourolle.paris/dtourolle/dreader-application.git
cd dreader-application

# Initialize and update submodules (includes dreader-hal)
git submodule update --init --recursive

# Create virtual environment
python3 -m venv venv
source venv/bin/activate

# Install dreader-application
pip install -e .
```

### 3. Install dreader-hal and Dependencies

The dreader-hal library has external driver dependencies in its `external/` directory:

```bash
# Install dreader-hal in editable mode
pip install -e external/dreader-hal

# Install external driver libraries
cd external/dreader-hal/external

# Install each driver
pip install -e IT8951
pip install -e PyFTtxx6
pip install -e PyBMA400
pip install -e PyPCF8523
pip install -e pi_ina219

cd ../../..  # Back to dreader-application root
```

### 4. Install Raspberry Pi GPIO (if on RPi)

```bash
pip install RPi.GPIO spidev
```

## Hardware Wiring

### IT8951 E-ink Display (SPI)
| IT8951 Pin | Raspberry Pi Pin | Description |
|------------|------------------|-------------|
| VCC | 3.3V (Pin 1) | Power supply |
| GND | GND (Pin 6) | Ground |
| MISO | GPIO 9 (Pin 21) | SPI MISO |
| MOSI | GPIO 10 (Pin 19) | SPI MOSI |
| SCK | GPIO 11 (Pin 23) | SPI Clock |
| CS | GPIO 8 (Pin 24) | SPI Chip Select |
| RST | GPIO 17 (Pin 11) | Reset |
| HRDY | GPIO 24 (Pin 18) | Ready signal |

### FT5316 Touch Panel (I2C)
| FT5316 Pin | Raspberry Pi Pin | Description |
|------------|------------------|-------------|
| VCC | 3.3V (Pin 1) | Power supply |
| GND | GND (Pin 6) | Ground |
| SDA | GPIO 2 (Pin 3) | I2C Data |
| SCL | GPIO 3 (Pin 5) | I2C Clock |
| INT | GPIO 27 (Pin 13) | Interrupt (optional) |

### BMA400 Accelerometer (I2C) - Optional
| BMA400 Pin | Raspberry Pi Pin | Description |
|------------|------------------|-------------|
| VCC | 3.3V (Pin 1) | Power supply |
| GND | GND (Pin 6) | Ground |
| SDA | GPIO 2 (Pin 3) | I2C Data |
| SCL | GPIO 3 (Pin 5) | I2C Clock |
| I2C Address | 0x14 or 0x15 | Check your module |

### PCF8523 RTC (I2C) - Optional
| PCF8523 Pin | Raspberry Pi Pin | Description |
|------------|------------------|-------------|
| VCC | 3.3V (Pin 1) | Power supply |
| GND | GND (Pin 6) | Ground |
| SDA | GPIO 2 (Pin 3) | I2C Data |
| SCL | GPIO 3 (Pin 5) | I2C Clock |
| BAT | CR2032 Battery | Backup battery |

### INA219 Power Monitor (I2C) - Optional
| INA219 Pin | Raspberry Pi Pin | Description |
|------------|------------------|-------------|
| VCC | 3.3V (Pin 1) | Power supply |
| GND | GND (Pin 6) | Ground |
| SDA | GPIO 2 (Pin 3) | I2C Data |
| SCL | GPIO 3 (Pin 5) | I2C Clock |
| VIN+ | Battery + | Positive voltage sense |
| VIN- | Shunt resistor | Through shunt to load |

**Note**: Multiple I2C devices can share the same SDA/SCL pins. Ensure each has a unique I2C address.

### GPIO Buttons (Optional)

Physical buttons for navigation:

| Button Function | GPIO Pin | Connection |
|----------------|----------|------------|
| Previous Page | GPIO 22 | Button between GPIO 22 and GND |
| Next Page | GPIO 27 | Button between GPIO 27 and GND |
| Power Off | GPIO 21 | Button between GPIO 21 and GND |

**Wiring:**
- Connect one side of button to GPIO pin
- Connect other side to GND
- Internal pull-up resistors are enabled in software
- Button press pulls GPIO LOW (0V)

**Available GPIOs** (BCM numbering):
- Safe to use: 5-27 (except 14, 15 if using UART)
- Avoid: GPIO 2, 3 (I2C), GPIO 7-11 (SPI), GPIO 14, 15 (UART)

## Verify Hardware Connections

### Check I2C Devices

```bash
# Scan I2C bus
i2cdetect -y 1

# Expected addresses (approximate):
# 0x38 - FT5316 touch panel
# 0x14 - BMA400 accelerometer
# 0x68 - PCF8523 RTC
# 0x40 - INA219 power monitor
```

### Check SPI

```bash
# List SPI devices
ls /dev/spi*
# Should show: /dev/spidev0.0  /dev/spidev0.1
```

## Important: VCOM Voltage

⚠️ **CRITICAL**: Each e-ink display has a unique VCOM voltage printed on a label (usually on the back).

- Check your display label for VCOM voltage (e.g., -2.06V, -1.98V, etc.)
- Pass this value to the HAL using the `--vcom` parameter
- Using incorrect VCOM can damage your display!

Example from label: `VCOM = -2.06V` → use `--vcom -2.06`

## Running on Hardware

### Recommended Method: Interactive Setup

The easiest way to get started is using the interactive setup script:

```bash
# 1. Run setup (detects hardware, configures GPIO buttons, etc.)
sudo python3 setup_rpi.py

# 2. Run DReader using generated config
python examples/run_on_hardware_config.py
```

The setup script will:
- Detect connected I2C devices (touch, accelerometer, RTC, power monitor)
- Enable I2C/SPI interfaces if needed
- Configure GPIO button mappings
- Set VCOM voltage
- Generate hardware_config.json

### Manual Configuration

Edit `hardware_config.json` to customize your hardware setup:

```json
{
  "display": {
    "width": 1872,
    "height": 1404,
    "vcom": -2.06
  },
  "gpio_buttons": {
    "enabled": true,
    "buttons": [
      {"name": "prev_page", "gpio": 22, "gesture": "swipe_right"},
      {"name": "next_page", "gpio": 27, "gesture": "swipe_left"},
      {"name": "power_off", "gpio": 21, "gesture": "long_press"}
    ]
  }
}
```

Then run:
```bash
python examples/run_on_hardware_config.py
```

### Direct Command Line (No Config File)

```bash
# Activate virtual environment
source venv/bin/activate

# Run with correct VCOM voltage (CHECK YOUR DISPLAY LABEL!)
python examples/run_on_hardware.py /path/to/books --vcom -2.06
```

### Testing Without Hardware (Virtual Display)

You can test the integration on your development machine using virtual display mode:

```bash
python examples/run_on_hardware.py /path/to/books \
    --virtual \
    --no-orientation \
    --no-rtc \
    --no-power
```

This creates a Tkinter window simulating the e-ink display.

### Advanced Options

```bash
# Disable optional hardware components
python examples/run_on_hardware.py /path/to/books \
    --vcom -2.06 \
    --no-orientation \  # Disable accelerometer
    --no-rtc \           # Disable RTC
    --no-power           # Disable battery monitor

# Show battery level periodically
python examples/run_on_hardware.py /path/to/books \
    --vcom -2.06 \
    --show-battery

# Custom battery capacity
python examples/run_on_hardware.py /path/to/books \
    --vcom -2.06 \
    --battery-capacity 5000  # mAh

# Enable verbose debug logging
python examples/run_on_hardware.py /path/to/books \
    --vcom -2.06 \
    --verbose

# Always start in library mode (ignore saved state)
python examples/run_on_hardware.py /path/to/books \
    --vcom -2.06 \
    --force-library
```

### Full Options Reference

```bash
python examples/run_on_hardware.py --help
```

## Touch Gestures

Once running, the following touch gestures are supported:

| Gesture | Action |
|---------|--------|
| **Swipe Left** | Next page |
| **Swipe Right** | Previous page |
| **Swipe Up** (from bottom) | Open navigation/TOC overlay |
| **Swipe Down** (from top) | Open settings overlay |
| **Tap** | Select book, word, or link |
| **Long Press** | Show word definition (if implemented) |
| **Pinch In/Out** | Adjust font size |

## Troubleshooting

### Display Not Working

1. **Check VCOM voltage** - Must match label on display
2. **Check SPI connections** - Run `ls /dev/spi*`
3. **Check SPI permissions** - Add user to `spi` group: `sudo usermod -a -G spi $USER`
4. **Try virtual display mode** - Test software without hardware

### Touch Not Working

1. **Check I2C connections** - Run `i2cdetect -y 1`
2. **Check I2C permissions** - Add user to `i2c` group: `sudo usermod -a -G i2c $USER`
3. **Check touch panel I2C address** - Should be 0x38 for FT5316
4. **Calibrate touch** - See dreader-hal calibration docs

### Import Errors

If you see `ModuleNotFoundError` for drivers:

```bash
# Ensure all external drivers are installed
cd external/dreader-hal/external
for dir in */; do pip install -e "$dir"; done
cd ../../..
```

### Permission Errors

```bash
# Add user to required groups
sudo usermod -a -G spi,i2c,gpio $USER

# Log out and back in for changes to take effect
```

### Display Ghosting

E-ink displays can show ghosting (image retention). The HAL automatically performs full refreshes every 10 page turns, but you can force one:

- The `RefreshMode.FULL` is automatically triggered periodically
- Check dreader-hal documentation for manual refresh control

## Programmatic Usage

You can also use the hardware HAL programmatically in your own scripts:

```python
import asyncio
from dreader.hal_hardware import HardwareDisplayHAL
from dreader.main import DReaderApplication, AppConfig

async def main():
    # Create hardware HAL
    hal = HardwareDisplayHAL(
        width=1872,
        height=1404,
        vcom=-2.06,  # YOUR DISPLAY'S VCOM!
        virtual_display=False,
        enable_orientation=True,
        enable_rtc=True,
        enable_power_monitor=True,
    )

    # Create application config
    config = AppConfig(
        display_hal=hal,
        library_path="/home/pi/Books",
        page_size=(1872, 1404),
    )

    # Create and run application
    app = DReaderApplication(config)

    try:
        await hal.initialize()
        await app.start()

        # Main event loop
        while app.is_running():
            event = await hal.get_touch_event()
            if event:
                await app.handle_touch(event)
            await asyncio.sleep(0.01)

    finally:
        await app.shutdown()
        await hal.cleanup()

if __name__ == '__main__':
    asyncio.run(main())
```

## Performance Notes

### E-ink Refresh Modes

The dreader-hal library automatically selects refresh modes:

- **Fast (DU mode)**: ~200ms - Used for text updates
- **Quality (GC16 mode)**: ~1000ms - Used for images
- **Full (INIT mode)**: ~1000ms - Used every 10 pages to clear ghosting

### Battery Life

With default settings:
- Active reading: ~10-20 hours
- Standby (display sleeping): ~1-2 weeks
- Enable low power mode for extended battery life

### Memory Usage

- Base application: ~30-50MB
- Per book: ~10-30MB (depends on book size)
- Ensure Raspberry Pi has at least 512MB RAM

## Next Steps

- See [README.md](README.md) for application features
- See [external/dreader-hal/README.md](external/dreader-hal/README.md) for HAL details
- See [examples/](examples/) for more usage examples
- Check dreader-hal documentation for touch calibration and advanced features

## Support

For hardware-specific issues, check:
- [dreader-hal issues](https://gitea.tourolle.paris/dtourolle/dreader-hal/issues)

For application issues, check:
- [dreader-application issues](https://gitea.tourolle.paris/dtourolle/dreader-application/issues)