class Recorder(RecorderParent):
"""
Sets up the recording stream through a National Instrument
Attributes
----------
device_name: str
Name of the device to be used for recording
max_value: float
Maximum value of recorded data
"""
#---------------- INITIALISATION METHODS -----------------------------------
def __init__(self,channels = 1,rate = 30000.0, chunk_size = 1000,
num_chunk = 4,device_name = None):
"""
Re-implemented from RecorderParent
"""
super().__init__(channels = channels,rate = rate,
chunk_size = chunk_size,num_chunk = num_chunk)
print('You are using National Instrument for recording')
self.device_name = None
self.set_device_by_name(device_name);
self.open_recorder()
self.trigger_init()
self.max_value = 10;
#---------------- DEVICE SETTING METHODS -----------------------------------
def set_device_by_name(self, name):
"""
Set the recording audio device by name.
Uses the first device found if no such device found.
"""
devices = self.available_devices()[0]
selected_device = None
if not devices:
print('No NI devices found')
return
if not name in devices:
print('Input device name not found, using the first device')
selected_device = devices[0]
else:
selected_device = name
print('Selected devices: %s' % selected_device)
self.device_name = selected_device
# Get audio device names
def available_devices(self):
"""
Get all the available input National Instrument devices.
Returns
----------
devices_name: List of str
Name of the device, e.g. Dev0
device_type: List of str
Type of device, e.g. USB-6003
"""
numBytesneeded = pdaq.DAQmxGetSysDevNames(None,0)
databuffer = pdaq.create_string_buffer(numBytesneeded)
pdaq.DAQmxGetSysDevNames(databuffer,numBytesneeded)
#device_list = []
devices_name = pdaq.string_at(databuffer).decode('utf-8').split(',')
device_type = []
for dev in devices_name:
numBytesneeded = pdaq.DAQmxGetDevProductType(dev,None,0)
databuffer = pdaq.create_string_buffer(numBytesneeded)
pdaq.DAQmxGetDevProductType(dev,databuffer,numBytesneeded)
device_type.append(pdaq.string_at(databuffer).decode('utf-8'))
#device_list.append(devices_name)
#device_list.append(device_type)
return(devices_name,device_type)
# Display the current selected device info
def current_device_info(self):
"""
Prints information about the current device set
"""
device_info = {}
info = ('Category', 'Type','Product', 'Number',
'Analog Trigger Support','Analog Input Trigger Types','Analog Input Channels (ai)', 'Analog Output Channels (ao)',
'ai Minimum Rate(Hz)', 'ai Maximum Rate(Single)(Hz)', 'ai Maximum Rate(Multi)(Hz)',
'Digital Trigger Support','Digital Input Trigger Types','Digital Ports', 'Digital Lines', 'Terminals')
funcs = (pdaq.DAQmxGetDevProductCategory, pdaq.DAQmxGetDevProductType,
pdaq.DAQmxGetDevProductNum, pdaq.DAQmxGetDevSerialNum,
pdaq.DAQmxGetDevAnlgTrigSupported, pdaq.DAQmxGetDevAITrigUsage,
pdaq.DAQmxGetDevAIPhysicalChans,pdaq.DAQmxGetDevAOPhysicalChans,
pdaq.DAQmxGetDevAIMinRate, pdaq.DAQmxGetDevAIMaxSingleChanRate, pdaq.DAQmxGetDevAIMaxMultiChanRate,
pdaq.DAQmxGetDevDigTrigSupported,pdaq.DAQmxGetDevDITrigUsage,
pdaq.DAQmxGetDevDIPorts,pdaq.DAQmxGetDevDILines,
pdaq.DAQmxGetDevTerminals)
var_types = (pdaq.int32, str, pdaq.uint32, pdaq.uint32,
pdaq.bool32,pdaq.int32,str,str,
pdaq.float64, pdaq.float64, pdaq.float64,
pdaq.bool32,pdaq.int32,str,str,str)
for i,f,v in zip(info,funcs,var_types):
try:
if v == str:
nBytes = f(self.device_name,None,0)
string_ptr = pdaq.create_string_buffer(nBytes)
f(self.device_name,string_ptr,nBytes)
if any( x in i for x in ('Channels','Ports')):
device_info[i] = len(string_ptr.value.decode().split(','))
else:
device_info[i] = string_ptr.value.decode()
else:
data = v()
f(self.device_name,data)
if 'Types' in i:
device_info[i] = bin(data.value)[2:].zfill(6)
else:
device_info[i] = data.value
except Exception as e:
print(e)
device_info[i] = '-'
pp.pprint(device_info)
def set_channels(self):
"""
Create the string to initiate the channels when assigning a Task
Returns
----------
channelname: str
The channel names to be used when assigning Task
e.g. Dev0/ai0:Dev0/ai1
"""
if self.channels >1:
channelname = '%s/ai0:%s/ai%i' % (self.device_name, self.device_name,self.channels-1)
elif self.channels == 1:
channelname = '%s/ai0' % self.device_name
print('Channels Name: %s' % channelname)
return channelname
#---------------- STREAMING METHODS -----------------------------------
# Convert data obtained into a proper array
def audiodata_to_array(self,data):
"""
Re-implemented from RecorderParent
"""
return data.reshape((-1,self.channels))/(2**15) *10.0
# Callback function for audio streaming
def stream_audio_callback(self):
"""
Callback function for audio streaming.
First, it writes data to the circular buffer,
then record data if it is recording,
finally check for any trigger.
Returns 0 as part of the callback format.
More info can be found in PyDAQmx documentation on Task class
"""
in_data = np.zeros(self.chunk_size*self.channels,dtype = np.int16)
read = pdaq.int32()
self.audio_stream.ReadBinaryI16(self.chunk_size,10.0,pdaq.DAQmx_Val_GroupByScanNumber,
in_data,self.chunk_size*self.channels,pdaq.byref(read),None)
data_array = self.audiodata_to_array(in_data)
self.write_buffer(data_array)
#self.rEmitter.newdata.emit()
if self.recording:
self.record_data(data_array)
# Trigger check
if self.trigger:
self._trigger_check_threshold(data_array)
return 0
def stream_init(self, playback = False):
"""
Re-implemented from RecorderParent.
"""
if self.audio_stream == None:
try:
self.audio_stream = Task()
self.audio_stream.stream_audio_callback = self.stream_audio_callback
self.audio_stream.CreateAIVoltageChan(self.set_channels(),"",
pdaq.DAQmx_Val_RSE,-10.0,10.0,
pdaq.DAQmx_Val_Volts,None)
self.audio_stream.CfgSampClkTiming("",self.rate,
pdaq.DAQmx_Val_Rising,pdaq.DAQmx_Val_ContSamps,
self.chunk_size)
self.audio_stream.AutoRegisterEveryNSamplesEvent(pdaq.DAQmx_Val_Acquired_Into_Buffer,
1000,0,name = 'stream_audio_callback')
self.stream_start()
return True
except:
t,v,tb = sys.exc_info()
print(t)
print(v)
print(traceback.format_tb(tb))
self.audio_stream = None
return False
# Start the streaming
def stream_start(self):
"""
Re-implemented from RecorderParent.
"""
if self.audio_stream:
task_done = pdaq.bool32()
self.audio_stream.GetTaskComplete(task_done)
if task_done.value:
self.audio_stream.StartTask()
else:
print('stream already started')
else:
print('No audio stream is set up')
# Stop the streaming
def stream_stop(self):
"""
Re-implemented from RecorderParent.
"""
if self.audio_stream:
task_done = pdaq.bool32()
self.audio_stream.GetTaskComplete(task_done)
if not task_done.value:
self.audio_stream.StopTask()
else:
print('stream already stopped')
else:
print('No audio stream is set up')
# Close the stream, probably needed if any parameter of the stream is changed
def stream_close(self):
"""
Re-implemented from RecorderParent.
"""
if self.audio_stream:
self.audio_stream.StopTask()
self.audio_stream.ClearTask()
self.audio_stream = None
