qt3piezo app -- set read channels to None

[gadamc]

The underlying library supports setting read channels to None, but the GUI application fails to handle this scenario.
As a user, I want to be able to control the actuator even if I don't have analog read channels from the actuator controller connected to NIDAQ analog inputs.

Should be an easy fix.

[gadamc]

suggested change to tkcontrollerapp.py

def build_controller():
    if args.test:
        controller = nipiezojenapy.BaseControl()
    else:
        if args.piezo_read_channels != 'None':
            read_channels = args.piezo_read_channels.split(',')
        else:
            read_channels = None
        controller = nipiezojenapy.PiezoControl(device_name = args.daq_name,
                                  write_channels = args.piezo_write_channels.split(','),
                                  read_channels = read_channels,
                                  move_settle_time = args.settle_time)
    return controller

[gadamc]

Or better yet, could run a check for valid values! If values do not appear to be allowed (can one call nidaqmx to ask the device???), then raise exception or do something else smart.

[gadamc]

def build_controller():
    if args.test:
        controller = nipiezojenapy.BaseControl()
    else:
        if args.piezo_read_channels == 'None':
            read_channels = None
        else:
            read_channels = args.piezo_read_channels.split(',')
            if len(read_channels) != 3:
                raise ValueError(f'{args.piezo_read_channels} should be a comma-separated list of three analog channel names') 
        controller = nipiezojenapy.PiezoControl(device_name = args.daq_name,
                                  write_channels = args.piezo_write_channels.split(','),
                                  read_channels = read_channels,
                                  move_settle_time = args.settle_time)
    return controller

[gadamc]

Maybe this is better

def build_controller():
    if args.test:
        controller = nipiezojenapy.BaseControl()
    else:
       
         if args.piezo_read_channels == 'None':
            read_channels = None
        else:
            read_channels = args.piezo_read_channels.split(',')
          
        controller = nipiezojenapy.PiezoControl(device_name = args.daq_name,
                                  write_channels = args.piezo_write_channels.split(','),
                                  read_channels = read_channels,
                                  move_settle_time = args.settle_time)
    return controller

then put the checks for name values inside the PiezoControl class.

class PiezoControl(BaseControl):

    def __init__(self, device_name: str,
                       write_channels: List[str] = ['ao0','ao1','ao2'],
                       read_channels: Optional[List[str]] = None,
                       scale_microns_per_volt: float = 8,
                       move_settle_time: float = 0.001,
                       min_position: float = 0.0,
                       max_position: float = 80.0) -> None:
        super().__init__()

        self.device_name = device_name

         if len(write_channels) != 3:
                raise ValueError(f'{write_channels} should be a list of three analog output channel names')
        self.write_channels = write_channels

        if len(read_channels) != 3:
                raise ValueError(f'{read_channels} should be a list of three analog input channel names')
        self.read_channels = read_channels

        self.scale_microns_per_volt = scale_microns_per_volt
        self.minimum_allowed_position = min_position
        self.maximum_allowed_position = max_position
        self.settling_time_in_seconds = move_settle_time #10 millisecond settle time
        self.last_write_values = [None, None, None]