Source code for PyExpLabSys.drivers.kjlc_pressure_gauge

""" Module contains driver for KJLC 3000 pressure gauge """
import serial
import time
from PyExpLabSys.common.supported_versions import python2_and_3

python2_and_3(__file__)

KJLC = None


class KJLC300(object):
    """ Class implements a KJLC interface """

    def __init__(self, port):
        self.connection = serial.Serial(
            port,
            baudrate=1200,
            bytesize=8,
            parity='N',
            stopbits=1,
            timeout=1,
            writeTimeout=1,
        )

    def close(self):
        """ Closes connection """
        self.connection.close()

    def read_software_version(self):
        """ Reads software version """
        self.connection.write('#01VER\r'.encode('ascii'))
        raw = self.connection.read(13)
        out = self._format_output(raw)
        return out

    def read_pressure(self):
        """ Reads pressure in Torr """
        self.connection.write('#01RD\r'.encode('ascii'))
        raw = self.connection.read(13)
        out = self._format_output(raw)
        try:
            out = float(out)
            out = 1.33322 * out
            time.sleep(0.1)
        except ValueError:
            out = 'error'
        return out

    def _format_output(self, string):
        """Strip *, the adress and a space from the beginning and a CR from the
        end
        """
        return string[4:-1]