Source code for pyoperant.interfaces.comedi_

import comedi
import subprocess, datetime
from pyoperant.interfaces import base_
from pyoperant import utils, InterfaceError


class ComediInterface(base_.BaseInterface):
    """docstring for ComediInterface"""
    def __init__(self,device_name,*args,**kwargs):
        super(ComediInterface, self).__init__(*args,**kwargs)
        self.device_name = device_name
        self.read_params = ('subdevice',
                            'channel',
                            )
        self.open()

    def open(self):
        self.device = comedi.comedi_open(self.device_name)
        if self.device is None:
            raise InterfaceError('could not open comedi device %s' % self.device_name)

    def close(self):
        s = comedi.comedi_close(self.device)
        if s < 0:
            raise InterfaceError('could not close comedi device %s(%s)' % (self.device_name, self.device))

    def _config_read(self,subdevice,channel):
        s = comedi.comedi_dio_config(self.device,subdevice,channel,comedi.COMEDI_INPUT)
        if s < 0:
            raise InterfaceError('could not configure comedi device "%s", subdevice %s, channel %s' % (self.device,subdevice,channel))
        else:
            return True

    def _config_write(self,subdevice,channel):
        s = comedi.comedi_dio_config(self.device,subdevice,channel,comedi.COMEDI_OUTPUT)
        if s < 0:
            raise InterfaceError('could not configure comedi device "%s", subdevice %s, channel %s' % (self.device,subdevice,channel))
        else:
            return True

    def _read_bool(self,subdevice,channel):
        """ read from comedi port
        """
        (s,v) = comedi.comedi_dio_read(self.device,subdevice,channel)
        if s:
            return (not v)
        else:
            raise InterfaceError('could not read from comedi device "%s", subdevice %s, channel %s' % (self.device,subdevice,channel))

    def _poll(self,subdevice,channel,timeout=None):
        """ runs a loop, querying for pecks. returns peck time or "GoodNite" exception """
        date_fmt = '%Y-%m-%d %H:%M:%S.%f'
        cmd = ['comedi_poll', self.device_name, '-s', str(subdevice), '-c', str(channel)]
        poll_command = utils.Command(cmd)
        status, output, error = poll_command.run(timeout=timeout)
        if status < 0:
            return None
        else:
            timestamp = output
            return datetime.datetime.strptime(timestamp.strip(),date_fmt)

    def _write_bool(self,subdevice,channel,value):
        """Write to comedi port
        """
        value = not value #invert the value for comedi
        
        s = comedi.comedi_dio_write(self.device,subdevice,channel,value)
        if s:
            return True
        else:
            raise InterfaceError('could not write to comedi device "%s", subdevice %s, channel %s' % (self.device,subdevice,channel))