from subprocess import call
import urllib
import xml.etree.ElementTree as ET
import time, math
## serial is not no buon
#import serialDecoder.py as sd
TELNET = "telnet 192.168.2.241 10001"
device = '/dev/cu.usbserial'
time_delay = 0.1
time_step = 0.001
class DataGetter():
"""Abstract class used for getting the voltage from a device"""
def __init__(self):
pass
def get(self):
pass
class PotentiometerMover():
"""Abstract class used for moving the potentiometer"""
def __init__(self):
pass
def move(self, direction, distance):
pass
class AD_DataGetter(DataGetter):
"""Class using the AD4ETH A2D converter for measuring the voltage"""
def __init__(self, url):
self.url = url
def get(self):
data = urllib.urlopen(self.url).read()
root = ET.fromstring(data)
inputs = root[0]
return float(inputs.attrib['val'])
class Serial_DataGetter(DataGetter):
"""Class using the VA18B voltmeter over serial connection"""
def __init__(self, serialDevice):
self.serialDevice
def get(self):
return float(self.serialDevice.getValue())
class Relay_PotentiometerMover(PotentiometerMover):
"""Class using the Quido relay for moving the potentiometer head"""
def __init__(self):
pass
def _sendCommand(self, relayId, high):
if relayId > 16 or relayId < 1:
raise ValueError("Value out of bounds")
stateLetter = ""
if high:
stateLetter = "H"
else:
stateLetter = "L"
stringToSend = "echo '*B1OS" + str(relayId) + stateLetter + "' | " + TELNET
call(stringToSend, shell=True)
def move(self, val):
for i in xrange(abs(val)):
if val > 0:
self._sendCommand(2, True)
self._sendCommand(3, True)
else:
self._sendCommand(2, False)
self._sendCommand(3, False)
print val
time.sleep(time_delay/(abs(val)/10.0))
self._sendCommand(1, True)
time.sleep(time_step)
self._sendCommand(1, False)
time.sleep(time_step)
class Potentiometer():
def __init__(self, voltageGetter, potentiometerMover, rang=0.05):
self.vG = voltageGetter
self.pM = potentiometerMover
self.rang = rang
def setValue(self, value):
while True:
offset = self._offset(value)
if abs(offset) < self.rang: # we are in range of the value
time.sleep(1)
print "done"
if abs(self._offset(value)) > self.rang:
print "final:",self._offset(value)
continue
print self._offset(value)
return
move = self._movement(offset)
print "moving", move
self._move(int(move)) # move the head a little
def _offset(self, value):
currentVal = self.getValue()
offset = currentVal - value
return offset
def _movement(self, offset):
if offset < 0:
sign = True
else:
sign = False
move = math.ceil((offset*10))
if sign:
move *= 1
return move
def _move(self, val):
self.pM.move(val)
def getValue(self):
return self.vG.get()
po = Relay_PotentiometerMover()
## Using AD
dataGetter = AD_DataGetter('http://192.168.2.242/data.xml')
va = Potentiometer(dataGetter, po)
print va.getValue()
va.setValue(2)
## Using serial device
#with sd.SerialDevice(device, 1) as s:
# dataGetter = Serial_DataGetter(s)
# va = Potentiometer(dataGetter)
