def find_all(cls, vid=None, pid=None):
"""
Returns all FTDI devices matching our vendor and product IDs.
:returns: list of devices
:raises: :py:class:`~alarmdecoder.util.CommError`
"""
if not have_pyftdi:
raise ImportError(
'The USBDevice class has been disabled due to missing requirement: pyftdi or pyusb.'
)
cls.__devices = []
query = cls.PRODUCT_IDS
if vid and pid:
query = [(vid, pid)]
try:
cls.__devices = Ftdi.find_all(query, nocache=True)
except (usb.core.USBError, FtdiError) as err:
raise CommError(
'Error enumerating AD2USB devices: {0}'.format(str(err)), err)
return cls.__devices
def find_all(cls, vid=None, pid=None):
"""
Returns all FTDI devices matching our vendor and product IDs.
:returns: list of devices
:raises: :py:class:`~alarmdecoder.util.CommError`
"""
if not have_pyftdi:
raise ImportError('The USBDevice class has been disabled due to missing requirement: pyftdi or pyusb.')
cls.__devices = []
query = cls.PRODUCT_IDS
if vid and pid:
query = [(vid, pid)]
try:
cls.__devices = Ftdi.find_all(query, nocache=True)
except (usb.core.USBError, FtdiError) as err:
raise CommError('Error enumerating AD2USB devices: {0}'.format(str(err)), err)
return cls.__devices
class Tunnel_DAC(Instrument):
def __init__(self, name, serial=None, channel='A0', numdacs=3, delay=1e-3):
'''
discover and initialize Tunnel_DAC hardware
Input:
serial - serial number of the FTDI converter
channel - 2 character channel id the DAC is connected to;
the first byte identifies the channel (A..D for current devices)
the second byte identifies the bit within that channel (0..7)
numdacs - number of DACs daisy-chained on that line
delay - communications delay assumed between PC and the USB converter
'''
logging.info(__name__ + ': Initializing instrument Tunnel_DAC')
Instrument.__init__(self, name, tags=['physical'])
self._conn = Ftdi()
# VIDs and PIDs of converters used
vps = [
(0x0403, 0x6011), # FTDI UM4232H 4ch
(0x0403, 0x6014) # FTDI UM232H 1ch
]
# explicitly clear device cache of UsbTools
#UsbTools.USBDEVICES = []
# find all devices and obtain serial numbers
devs = self._conn.find_all(vps)
# filter list by serial number if provided
if (serial != None):
devs = [dev for dev in devs if dev[2] == serial]
if (len(devs) == 0):
logging.error(__name__ + ': failed to find matching FTDI devices.')
elif (len(devs) > 1):
logging.error(
__name__ +
': more than one converter found and no serial number given.')
logging.info(__name__ + ': available devices are: %s.' %
str([dev[2] for dev in devs]))
vid, pid, self._serial, channels, description = devs[0]
# parse channel string
if (len(channel) != 2):
logging.error(
__name__ +
': channel identifier must be a string of length 2. ex. A0, D5.'
)
self._channel = 1 + ord(channel[0]) - ord('A')
self._bit = ord(channel[1]) - ord('0')
if ((self._channel < 1) or (self._channel > channels)):
logging.error(__name__ +
': channel %c is not supported by this device.' %
(chr(ord('A') + self._channel - 1)))
if ((self._bit < 0) or (self._bit > 7)):
logging.error(__name__ +
': subchannel must be between 0 and 7, not %d.' %
self._bit)
# open device
self._conn.open(vid, pid, interface=self._channel, serial=self._serial)
logging.info(__name__ +
': using converter with serial #%s' % self._serial)
self._conn.set_bitmode(0xFF, Ftdi.BITMODE_BITBANG)
# 80k generates bit durations of 12.5us, 80 is magic :(
# magic?: 4 from incorrect BITBANG handling of pyftdi, 2.5 from 120MHz instead of 48MHz clock of H devices
# original matlab code uses 19kS/s
self._conn.set_baudrate(19000 / 80)
# house keeping
self._numdacs = numdacs
self._sleeptime = (
10. + 16. * self._numdacs
) * 12.5e-6 + delay # 1st term from hardware parameters, 2nd term from USB
self._minval = -5000.
self._maxval = 5000.
self._resolution = 16 # DAC resolution in bits
self._voltages = [0.] * numdacs
self.add_parameter('voltage',
type=types.FloatType,
flags=Instrument.FLAG_SET,
channels=(1, self._numdacs),
minval=self._minval,
maxval=self._maxval,
units='mV',
format='%.02f') # tags=['sweep']
self.add_function('set_voltages')
self.add_function('commit')
def _encode(self, data, channel=0, bits_per_item=16, big_endian=True):
'''
convert binary data into line symbols
the tunnel electronic DAC logic box triggers on rising
signal edges and samples data after 18us. we use a line
code with three bits of duration 12us, where a logical 1
is encoded as B"110" and a logical 0 is encoded as B"100".
the line data is returned as a byte string with three bytes/symbol.
Input:
data - a vector of data entities (usually a string or list of integers)
channel - a number in [0, 7] specifying the output bit on the USB-to-UART chip
bits_per_item - number of bits to extract from each element of the data vector
'''
# build line code for the requested channel
line_1 = chr(1 << channel)
line_0 = chr(0)
line_code = [
''.join([line_0, line_1, line_1]),
''.join([line_0, line_1, line_0])
]
# do actual encoding
result = []
result.append(10 * line_0)
for item in data:
for bit in (range(bits_per_item - 1, -1, -1)
if big_endian else range(0, bits_per_item)):
result.append(line_code[1 if (item & (1 << bit)) else 0])
result.append(10 * line_0)
return ''.join(result)
def commit(self):
'''
send updated parameter values to the physical DACs via USB
'''
# normalize, scale, clip voltages
voltages = [
-1 + 2 * (x - self._minval) / (self._maxval - self._minval)
for x in self._voltages
]
voltages = [
max(
-2**(self._resolution - 1),
min(2**(self._resolution - 1) - 1,
int(2**(self._resolution - 1) * x))) for x in voltages
]
# encode and send
data = self._encode(reversed(voltages), self._bit, self._resolution)
self._conn.write_data(data)
# wait for the FTDI fifo to clock the data to the DACs
sleep(self._sleeptime)
def do_set_voltage(self, value, channel):
'''
immediately update voltage on channel ch
parameter checking is done by qtlab
'''
self._voltages[channel - 1] = value
self.commit()
def set_voltages(self, valuedict):
'''
update voltages on several channels simultaneously
todo: update instrument panel display
'''
for channel, value in valuedict.iteritems():
# bounds checking & clipping
if ((channel < 1) or (channel > self._numdacs)):
logging.error(__name__ +
': channel %d out of range.' % channel)
continue
value = float(value)
if ((value < self._minval) or (value >= self._maxval)):
logging.error(__name__ +
': value %f out of range. clipping.' % value)
value = max(self._minval,
min(self._maxval,
value)) # does not handle maxval correctly
self._voltages[channel - 1] = value
self.commit()
def find_all():
devices = Ftdi.find_all([(FTDI_VENDOR_ID, FTDI_PRODUCT_ID)])
return [(serial_str, description) for
vendor_id, product_id, serial_str, num_interfaces,
description in devices]
def find_all():
devices = Ftdi.find_all([(FTDI_VENDOR_ID, FTDI_PRODUCT_ID)])
return [(serial_str, description) for vendor_id, product_id,
serial_str, num_interfaces, description in devices]
class Tunnel_DAC(Instrument):
def __init__(self, name, serial = None, channel = 'A0', numdacs=3, delay = 1e-3):
'''
discover and initialize Tunnel_DAC hardware
Input:
serial - serial number of the FTDI converter
channel - 2 character channel id the DAC is connected to;
the first byte identifies the channel (A..D for current devices)
the second byte identifies the bit within that channel (0..7)
numdacs - number of DACs daisy-chained on that line
delay - communications delay assumed between PC and the USB converter
'''
logging.info(__name__+ ': Initializing instrument Tunnel_DAC')
Instrument.__init__(self, name, tags=['physical'])
self._conn = Ftdi()
# VIDs and PIDs of converters used
vps = [
(0x0403, 0x6011), # FTDI UM4232H 4ch
(0x0403, 0x6014) # FTDI UM232H 1ch
]
# explicitly clear device cache of UsbTools
#UsbTools.USBDEVICES = []
# find all devices and obtain serial numbers
devs = self._conn.find_all(vps)
# filter list by serial number if provided
if(serial != None):
devs = [dev for dev in devs if dev[2] == serial]
if(len(devs) == 0):
logging.error(__name__ + ': failed to find matching FTDI devices.')
elif(len(devs) > 1):
logging.error(__name__ + ': more than one converter found and no serial number given.')
logging.info(__name__ + ': available devices are: %s.'%str([dev[2] for dev in devs]))
vid, pid, self._serial, channels, description = devs[0]
# parse channel string
if(len(channel) != 2):
logging.error(__name__ + ': channel identifier must be a string of length 2. ex. A0, D5.')
self._channel = 1 + ord(channel[0]) - ord('A')
self._bit = ord(channel[1]) - ord('0')
if((self._channel < 1) or (self._channel > channels)):
logging.error(__name__ + ': channel %c is not supported by this device.'%(chr(ord('A')+self._channel-1)))
if((self._bit < 0) or (self._bit > 7)):
logging.error(__name__ + ': subchannel must be between 0 and 7, not %d.'%self._bit)
# open device
self._conn.open(vid, pid, interface = self._channel, serial = self._serial)
logging.info(__name__ + ': using converter with serial #%s'%self._serial)
self._conn.set_bitmode(0xFF, Ftdi.BITMODE_BITBANG)
# 80k generates bit durations of 12.5us, 80 is magic :(
# magic?: 4 from incorrect BITBANG handling of pyftdi, 2.5 from 120MHz instead of 48MHz clock of H devices
# original matlab code uses 19kS/s
self._conn.set_baudrate(19000/80)
# house keeping
self._numdacs = numdacs
self._sleeptime = (10. + 16.*self._numdacs)*12.5e-6 + delay # 1st term from hardware parameters, 2nd term from USB
self._minval = -5000.
self._maxval = 5000.
self._resolution = 16 # DAC resolution in bits
self._voltages = [0.]*numdacs
self.add_parameter('voltage', type=types.FloatType, flags=Instrument.FLAG_SET, channels=(1, self._numdacs),
minval = self._minval, maxval = self._maxval, units='mV', format = '%.02f') # tags=['sweep']
self.add_function('set_voltages')
self.add_function('commit')
def _encode(self, data, channel = 0, bits_per_item = 16, big_endian = True):
'''
convert binary data into line symbols
the tunnel electronic DAC logic box triggers on rising
signal edges and samples data after 18us. we use a line
code with three bits of duration 12us, where a logical 1
is encoded as B"110" and a logical 0 is encoded as B"100".
the line data is returned as a byte string with three bytes/symbol.
Input:
data - a vector of data entities (usually a string or list of integers)
channel - a number in [0, 7] specifying the output bit on the USB-to-UART chip
bits_per_item - number of bits to extract from each element of the data vector
'''
# build line code for the requested channel
line_1 = chr(1<<channel)
line_0 = chr(0)
line_code = [''.join([line_0, line_1, line_1]), ''.join([line_0, line_1, line_0])]
# do actual encoding
result = []
result.append(10*line_0)
for item in data:
for bit in (range(bits_per_item-1, -1, -1) if big_endian else range(0, bits_per_item)):
result.append(line_code[1 if(item & (1<<bit)) else 0])
result.append(10*line_0)
return ''.join(result)
def commit(self):
'''
send updated parameter values to the physical DACs via USB
'''
# normalize, scale, clip voltages
voltages = [-1+2*(x-self._minval)/(self._maxval-self._minval) for x in self._voltages]
voltages = [max(-2**(self._resolution-1), min(2**(self._resolution-1)-1, int(2**(self._resolution-1)*x))) for x in voltages]
# encode and send
data = self._encode(reversed(voltages), self._bit, self._resolution)
self._conn.write_data(data)
# wait for the FTDI fifo to clock the data to the DACs
sleep(self._sleeptime)
def do_set_voltage(self, value, channel):
'''
immediately update voltage on channel ch
parameter checking is done by qtlab
'''
self._voltages[channel-1] = value
self.commit()
def set_voltages(self, valuedict):
'''
update voltages on several channels simultaneously
todo: update instrument panel display
'''
for channel, value in valuedict.iteritems():
# bounds checking & clipping
if((channel < 1) or (channel > self._numdacs)):
logging.error(__name__ + ': channel %d out of range.'%channel)
continue
value = float(value)
if((value < self._minval) or (value >= self._maxval)):
logging.error(__name__ + ': value %f out of range. clipping.'%value)
value = max(self._minval, min(self._maxval, value)) # does not handle maxval correctly
self._voltages[channel-1] = value
self.commit()