# Developing Your Own Driver

This section guides you through the process of creating your own device driver for the CGSE framework, using CGSE-DUMMY as a reference. It covers the key steps, extension points, and best practices to help you build robust, maintainable, and CGSE-compliant drivers.

## 1. Use CGSE-DUMMY as a Template

Start by studying the structure and code of CGSE-DUMMY. The project provides both synchronous (`dummy_cs.py`, `dummy_dev.py`) and asynchronous (`dummy_acs.py`, `dummy_adev.py`) driver examples, as well as a device simulator (`dummy_sim.py`).

- **Copy and Rename:** Duplicate the relevant files and rename them to match your device or project.
- **Update Configuration:** Adjust `settings.yaml` or your own configuration files to reflect your device's parameters (e.g., port numbers, device IDs).

## 2. Implement Device-Specific Logic

- **Device Driver:** Implement the logic for communicating with your hardware or simulation. Replace or extend the methods in the driver class to handle your device's commands, data acquisition, and state management.
- **Simulator (Optional):** If you want to support development without hardware, adapt or extend the simulator to mimic your device's behavior.

## 3. Define and Register SCPI Commands

- **Command Set:** Define the SCPI or SCPI-like commands your device will support. Use the approach in `scpi.py` to map commands to handler functions.
- **Translation Functions:** Implement translation functions for parsing arguments and formatting responses, as shown in CGSE-DUMMY.
- **Extensibility:** Consider using a registry or decorator pattern to make it easy to add new commands.

## 4. Integrate with the Control Server

- **Command Dispatch:** Ensure your control server correctly parses incoming commands and dispatches them to the appropriate driver methods.
- **Session Management:** Handle multiple sessions or clients if needed, especially for asynchronous drivers.

## 5. Follow Best Practices

- **Error Handling:** Implement robust error handling and clear error messages for invalid commands or device states.
- **Logging:** Add logging for key events, errors, and state changes to aid debugging and monitoring.
- **Testing:** Write unit and integration tests for your driver and simulator. Use the CGSE-DUMMY test suite as a starting point.
- **Documentation:** Document your command set, configuration options, and any device-specific behaviors.

## 6. Common Pitfalls and Troubleshooting

- **Blocking Operations:** Avoid blocking calls in asynchronous drivers; use `asyncio`-compatible libraries and patterns.
- **State Management:** Carefully manage device state, especially when handling concurrent commands.
- **Protocol Compliance:** Ensure your command set and responses are consistent and, if possible, compatible with SCPI or your chosen protocol.

## 7. Example: Adding a New Command

Suppose you want to add a `MEAS:TEMP?` command to query temperature:

1. **Define the handler in your driver:**
   ```python
   def get_temperature(self):
       return self._read_temperature_sensor()
   ```
2. **Register the command in your SCPI mapping:**
   ```python
   'MEAS:TEMP?': {'get': lambda self: self.get_temperature()},
   ```
3. **Update documentation and tests** to cover the new command.

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By following these steps and using CGSE-DUMMY as a reference, you can efficiently develop, test, and maintain your own device drivers for the CGSE framework.

Next: [Testing and Validation](./testing_and_validation.md)
