Source code for phobos.classes.filter_wheel

# External imports
import time
import os

# Internal imports
from .. import serial
from .config import Config

from ..utils import Singleton



class FilterWheel(metaclass=Singleton):


    def __init__(self):
        """
        Singleton Class to control the Thorlabs filter wheel. The wheel has 6 positions:
            - 1: ND?
            - 2: ND?
            - 3: ND?
            - 4: ND?
            - 5: ND?
            - 6: ND?
        """
        config = Config()
        
        try:
            port = config.get('filter_wheel.port')
            self.session = serial.Serial(port, 115200, timeout=0.1)
            print(f"Filter Wheel connected on port {port}")
            self._connected = True
        except Exception as e:
            if not os.environ.get("PHOBOS_SANDBOX"):
                 print(f"⚠️ FilterWheel connection failed: {e}")
            self._connected = False

        


    def reset(self):
        """
        Reset the filter wheel to the default position defined in config.
        """
        selected_filter = Config().get('filter_wheel.selected_filter', 1)
        self.move(selected_filter)

        
    def _purge(self):
        """
        Purge all the history of the responses of the filter wheel.
        """
        # Reading the lines actually flush the info after the request
        dummy = self.session.readlines()
    


    def close(self):
        """
        Close the serial connection.
        """
        self.session.close()    


        


    def get(self):
        """
        Get the current info from the filter wheel.

        Returns
        -------
        response : str
            Status of the wheel.

        """
        self._purge() # flush
        self.session.write("pos?\r".encode())
        response = self.session.readline().decode()
        
        return response


        


    def get_pos(self):
        """
        Returns the current position of the filter wheel.

        Returns
        -------
        slot : int
            Current position number of the wheel.

        """
        time.sleep(0.1)
        resp = self.get()
        
        slot = int(resp[5])
        
        return slot




    def move(self, slot:int):
        """
        Move the filter wheel to the specified position.

        Parameters
        ----------
        slot : int
            Position number of the wheel to reach.
        """
        print('FILT - Move to position '+str(slot))
        self.session.write(("pos="+str(slot)+"\r").encode())
        self.wait()


    


    def wait(self) -> None:
        """
        Wait for the motor to reach the target position.
        """
        position = ''
        while len(position) == 0:
            position = self.get()
            time.sleep(0.1)