scanengine-3/hardware/helios_laser.py

"""
Helios Laser System Driver
Basic implementation for controlling the Helios pulsed laser.
"""

import serial
import time
import logging
from typing import Optional, List
from enum import Enum

logger = logging.getLogger(__name__)


class PulseMode(Enum):
    """Helios pulse mode enumeration"""
    SINGLE_PULSE = 0
    CONTINUOUS_GATING = 1
    CONTINUOUS_PULSING = 2


class HeliosLaser:
    """
    Driver for Helios pulsed laser system.

    Communication: RS-232, 9600 baud, 8N1
    Commands are ASCII strings terminated with CR
    """

    def __init__(self, port: str = None, timeout: float = 1.0):
        """
        Initialize Helios laser driver.

        Args:
            port: Serial port (e.g., '/dev/ttyUSB0' or 'COM5')
            timeout: Serial timeout in seconds
        """
        self.port = port
        self.timeout = timeout
        self.serial = None
        self.is_connected = False

    @staticmethod
    def list_available_ports() -> List[str]:
        """List available serial ports"""
        import serial.tools.list_ports
        ports = serial.tools.list_ports.comports()
        return [port.device for port in ports]

    def connect(self, port: str = None) -> bool:
        """
        Connect to the Helios laser.

        Args:
            port: Serial port (uses stored port if None)

        Returns:
            True if connection successful
        """
        if port:
            self.port = port

        if not self.port:
            logger.error("No port specified")
            return False

        try:
            self.serial = serial.Serial(
                port=self.port,
                baudrate=9600,
                bytesize=serial.EIGHTBITS,
                parity=serial.PARITY_NONE,
                stopbits=serial.STOPBITS_ONE,
                timeout=self.timeout
            )
            time.sleep(0.1)  # Allow time for connection to stabilize
            self.is_connected = True
            logger.info(f"Connected to Helios laser on {self.port}")
            return True

        except Exception as e:
            logger.error(f"Failed to connect to Helios laser: {e}")
            self.is_connected = False
            return False

    def disconnect(self):
        """Disconnect from the laser"""
        if self.serial and self.serial.is_open:
            try:
                # Disable laser before disconnecting
                self.set_laser_enable(False)
                self.serial.close()
                logger.info("Disconnected from Helios laser")
            except Exception as e:
                logger.error(f"Error during disconnect: {e}")

        self.is_connected = False
        self.serial = None

    def _send_command(self, command: str) -> bool:
        """
        Send a command to the laser.

        Args:
            command: ASCII command string (without CR)

        Returns:
            True if sent successfully
        """
        if not self.is_connected or not self.serial:
            logger.error("Not connected to laser")
            return False

        try:
            cmd_bytes = (command + '\r').encode('ascii')
            self.serial.write(cmd_bytes)
            logger.debug(f"Sent command: {command}")
            return True

        except Exception as e:
            logger.error(f"Failed to send command '{command}': {e}")
            return False

    def _query(self, command: str) -> Optional[str]:
        """
        Send a query and read response.

        Args:
            command: ASCII query command (without CR)

        Returns:
            Response string or None if error
        """
        if not self._send_command(command):
            return None

        try:
            response = self.serial.readline().decode('ascii').strip()
            logger.debug(f"Query '{command}' response: {response}")
            return response

        except Exception as e:
            logger.error(f"Failed to read response for '{command}': {e}")
            return None

    def set_frequency_hz(self, frequency: int) -> bool:
        """
        Set laser pulse frequency in Hz.

        Args:
            frequency: Frequency in Hz (16700 - 125000)

        Returns:
            True if successful
        """
        if not (16700 <= frequency <= 125000):
            logger.error(f"Frequency {frequency} Hz out of range (16700-125000)")
            return False

        # Convert frequency to period in nanoseconds
        period_ns = int(1e9 / frequency)

        command = f"FP={period_ns}"
        return self._send_command(command)

    def set_current_ma(self, current: int) -> bool:
        """
        Set pump diode current in mA.

        Args:
            current: Current in mA (0 - 7000)

        Returns:
            True if successful
        """
        if not (0 <= current <= 7000):
            logger.error(f"Current {current} mA out of range (0-7000)")
            return False

        command = f"PC={current}"
        return self._send_command(command)

    def set_pulse_mode(self, mode: PulseMode) -> bool:
        """
        Set pulse mode.

        Args:
            mode: PulseMode enumeration value

        Returns:
            True if successful
        """
        command = f"PM={mode.value}"
        return self._send_command(command)

    def set_laser_enable(self, enable: bool) -> bool:
        """
        Enable or disable laser emission.

        Args:
            enable: True to enable, False to disable

        Returns:
            True if successful
        """
        command = f"LE={1 if enable else 0}"
        success = self._send_command(command)

        if success:
            state = "enabled" if enable else "disabled"
            logger.info(f"Laser {state}")

        return success

    def is_laser_enabled(self) -> bool:
        """
        Check if laser is currently enabled.

        Returns:
            True if laser is enabled
        """
        response = self._query("LE?")
        if response:
            try:
                return int(response) == 1
            except ValueError:
                logger.error(f"Invalid response for LE?: {response}")
        return False

    def get_frequency_hz(self) -> Optional[int]:
        """
        Get current laser frequency in Hz.

        Returns:
            Frequency in Hz or None if error
        """
        response = self._query("FP?")
        if response:
            try:
                period_ns = int(response)
                return int(1e9 / period_ns)
            except (ValueError, ZeroDivisionError):
                logger.error(f"Invalid response for FP?: {response}")
        return None

    def get_current_ma(self) -> Optional[int]:
        """
        Get current pump diode current in mA.

        Returns:
            Current in mA or None if error
        """
        response = self._query("PC?")
        if response:
            try:
                return int(response)
            except ValueError:
                logger.error(f"Invalid response for PC?: {response}")
        return None

    def get_power_mw(self) -> Optional[float]:
        """
        Get laser output power in mW.

        Returns:
            Power in mW or None if error
        """
        response = self._query("PO?")
        if response:
            try:
                return float(response)
            except ValueError:
                logger.error(f"Invalid response for PO?: {response}")
        return None

    def get_controller_serial(self) -> Optional[str]:
        """
        Get controller serial number.

        Returns:
            Serial number string or None if error
        """
        return self._query("SN?")

    def get_head_serial(self) -> Optional[str]:
        """
        Get laser head serial number.

        Returns:
            Serial number string or None if error
        """
        return self._query("HSN?")

    def __del__(self):
        """Destructor - ensure cleanup"""
        self.disconnect()