frappa_bypass.py

"""
Move Andor FRAPPA galvos to bypass position

Usage:
    python frappa_bypass.py <bypass>

Example:
    C:\Python27\python C:\MM\frappa_bypass.py 6.5
"""

# Default bypass value
BYPASS = 6.5  # degrees

from ctypes import CDLL, c_char_p, c_void_p, c_double, byref, Structure
from sys import exit, argv

# Get value from commandline if supplied
if len(argv) == 2:
    BYPASS = float(argv[1])

print('Setting FRAPPA bypass to %.2f degrees' % BYPASS)

galvo_max = 15.0  # degrees
galvo_min = -15.0  # degrees
gavo_res = 0.0005

def degrees_to_steps(degrees):
    conversion_factor = pow(2.0, 35.0) / galvo_max
    steps = degrees * conversion_factor
    return steps

error_code = {
    0: 'no error',
    1: 'unknown error',
    2: 'method not implemented yet',
    30: 'invalid first argument',
    31: 'invalid second argument',
    32: 'invalid third argument',
    33: 'invalid fourth argument',
    34: 'invalid fifth argument',
    35: 'invalid sixth argument',
    36: 'invalid seventh argument',
    37: 'invalid eighth argument',
    100: 'invalid LSM handle',
    102: 'error opening the COM port',
    100000: 'the LSM is not calibrated',
    100001: 'failed to clear the scan protocol from the LSM',
    100002: 'failed to set a new scan protocol',
    100003: 'failed to start the execution of the scan protocol',
    100004: 'failed to abort the scan protocol',
    100005: 'unable to determine the blanking time between lines',
    100006: 'protocol is not supported',
    100007: 'error creating the protocol',
    100008: 'error calculating intersections between scan lines and region to scan',
    100009: 'number of created commands for a protocol is not as expected',
    }

# Python print statements stop working after this CDLL line in
# Micro-Manager's Script Panel probably due to this library's log4cxx
# module.
lib = CDLL('C:/MM/tillimic.dll')

# Connect to a specific LSM device.
port = c_char_p('COM1')
handle = c_void_p(0)
print('Initializing FRAPPA...')
ret = -1
ret = lib.LSM_Open(port, byref(handle))
# int LSM_Open(const char *port, void **handle)
if (ret != 0):
    exit('Error from LSM_Open(): %s (Code %d)'
         % (error_code[ret], ret))

### Set the resting position of the galvos.
##print('Setting Rest position to %.2f...' % BYPASS) 
class LSM_Coordinate(Structure):  # struct
    """Steps values for galvo"""
    _fields_ = [("x", c_double),
                ("y", c_double)]
rest_position = LSM_Coordinate(degrees_to_steps(BYPASS),
                               degrees_to_steps(galvo_min))
ret = -1
ret = lib.LSM_SetRestPosition(handle, rest_position)
# int LSM_SetRestPosition (void *handle, LSM_Coordinate galvoPos)
if (ret != 0):
    exit('Error from LSM_SetRestPosition(): %s (Code %d)'
         % (error_code[ret], ret))

# Gets the resting position of the galvos.
get_position = LSM_Coordinate(-999,-999)
ret = -1
ret = lib.LSM_GetRestPosition(handle, byref(get_position))
# int LSM_GetRestPosition (void *handle, LSM_Coordinate *galvoPos)
if (ret != 0):
    exit('Error from LSM_GetRestPosition(): %s (Code %d)'
         % (error_code[ret], ret))

# Move both scanning galvo absolute compared to their central position
# (uncalibrated).
ret = lib.LSM_SetGalvoRawPosition(handle, rest_position)
# int LSM_SetGalvoRawPosition (void *handle, LSM_Coordinate *galvoCoordinate)
if (ret != 0):
    exit('Error from LSM_SetGalvoRawPosition(): %s (Code %d)'
         % (error_code[ret], ret))

# Disconnect from device.
ret = -1
ret = lib.LSM_Close(handle)
# int LSM_Close (void *handle)
if (ret != 0):
    exit('Error from LSM_Close(): %s (Code %d)'
         % (error_code[ret], ret))

print('Rest position is now %.2f, %.2f' % (get_position.x, get_position.y))