ThorlabsK10CR1.py

import ctypes as c
import numpy as np
import os, time

dllname = os.path.join(os.path.dirname(__file__), 'Thorlabs.MotionControl.IntegratedStepperMotors.dll')

if not os.path.exists(dllname):
    print "ERROR: DLL not found"

p = c.windll.LoadLibrary(dllname)

def getHardwareInfo(SN):
    
    modelNo =         c.c_buffer(255)
    sizeOfModelNo =   c.c_ulong(255)
    hardwareType =    c.c_ushort()
    numChannels =     c.c_short()
    notes =           c.c_buffer(255)
    sizeOfNotes =     c.c_ulong(255)
    firmwareVersion = c.c_ulong()
    hardwareVersion = c.c_ushort()
    modState        = c.c_ushort()
    # p.PCC_GetHardwareInfo(SN)

    p.ISC_GetHardwareInfo(SN, 
                          c.pointer(modelNo), 
                          c.pointer(sizeOfModelNo), 
                          c.pointer(hardwareType),
                          c.pointer(numChannels),
                          c.pointer(notes),
                          c.pointer(sizeOfNotes),
                          c.pointer(firmwareVersion),
                          c.pointer(hardwareVersion),
                          c.pointer(modState) )
    

    return [x.value for x in (modelNo, sizeOfModelNo, hardwareType, numChannels, notes, sizeOfNotes, firmwareVersion, hardwareVersion, modState)]


def getMotorParamsExt(SN):
	# this doesn't work for some reason...
	stepsPerRev =  c.c_double()
	gearBoxRatio = c.c_double()
	pitch =        c.c_double()

	print p.ISC_GetMotorParamsExt(SN, c.pointer(stepsPerRev), 
							       c.pointer(gearBoxRatio), 
							       c.pointer(pitch))

	return stepsPerRev.value, gearBoxRatio.value, pitch.value


def getDeviceList():
    p.TLI_BuildDeviceList()
    receiveBuffer = c.c_buffer(255)
    sizeOfBuffer  = c.c_ulong(255)
    p.TLI_GetDeviceListExt(c.pointer(receiveBuffer), c.pointer(sizeOfBuffer))
    return [x for x in (receiveBuffer.value).split(',')[:-1]]


def MoveToPosition(SN, deviceUnits, timeout=10, queryDelay=0.01, tolerance=1):
	"""
	Moves the rotation stage to a certain position (given by device units).
	This call blocks future action until the move is complete.
	The timeout is in seconds

	SN is a c_buffer of the serial number string
	deviceUnits shold be a int.
	tolerance is when the blocking should end (device units)
	"""
	p.ISC_MoveToPosition(SN, c.c_int(int(deviceUnits)))

	t = time.time()

	while time.time()<(t+timeout):
		p.ISC_RequestStatus(SN) # order the stage to find out its location
		currentPosition = p.ISC_GetPosition(SN)
		error = currentPosition - deviceUnits
		if np.abs(error)<tolerance: 
			return
		else:
			time.sleep(queryDelay)


	print 'Timeout!'

print 'getting serial number...'
serialNumber = getDeviceList()[0]
print 'serial number is: %s'%serialNumber
SN = c.c_buffer(serialNumber)

print 'Opening communications to rotation stage...'
print p.ISC_Open(SN)
print 'Success!'

print getHardwareInfo(SN)
print p.ISC_StartPolling(SN,c.c_int(200))
print p.ISC_LoadSettings(SN)

p.ISC_RequestStatusBits(SN)
print  bin(p.ISC_GetStatusBits(SN))


stepsPerRev, gearBoxRatio, pitch = getMotorParamsExt(SN)
print stepsPerRev, gearBoxRatio, pitch
microstepsPerFullstep = 2048 # from https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=8750
conversion = stepsPerRev * microstepsPerFullstep * gearBoxRatio / pitch # convert to degrees
print conversion

print 'Moving to location zero'
MoveToPosition(SN, 0)


for degrees in np.arange(0,30,5):
	deviceUnits = int(degrees*conversion) # this involved rounding!
	print 'Moving to %5.3f degrees (%i Device Units)...'%(degrees, deviceUnits)
	MoveToPosition(SN, deviceUnits)
	new_position = p.ISC_GetPosition(SN)
	new_degrees  = new_position/conversion
	print 'Reported: %5.3f degrees (%i Device Units).'%(new_degrees, new_position)