def make_chlist(chans):
# list containing the chans, gains and referencing
nchans = len(chans) #number of channels
#wrappers include a "chanlist" object (just an Unsigned Int array) for holding the chanlist information
mylist = c.chanlist(nchans) #create a chanlist of length nchans
#now pack the channel, gain and reference information into the chanlist object
#N.B. the CR_PACK and other comedi macros are now python functions
for index in range(nchans):
mylist[index]=c.cr_pack(chans[index].no, chans[index].devrange, chans[index].aref)
return mylist
def make_chlist(chans):
# list containing the chans, gains and referencing
nchans = len(chans) #number of channels
#wrappers include a "chanlist" object (just an Unsigned Int array) for holding the chanlist information
mylist = c.chanlist(nchans) #create a chanlist of length nchans
#now pack the channel, gain and reference information into the chanlist object
#N.B. the CR_PACK and other comedi macros are now python functions
for index in range(nchans):
mylist[index] = c.cr_pack(chans[index].no, chans[index].devrange,
chans[index].aref)
return mylist
def prepare_cmd(self,channels,gains,aref,freq):
#First create the channel setup
nchans = size(channels)
channel_config = c.chanlist(nchans) #create a chanlist of length nchans
print channel_config
print channels
for index in range(nchans):
channel_config[index]=c.cr_pack(channels[index], gains[index], aref[index])
#Then create the command
cmd = c.comedi_cmd_struct()
cmd.subdev = self.subdevice
cmd.flags = 0
cmd.start_src = c.TRIG_NOW
cmd.start_arg = 0
cmd.scan_begin_src = c.TRIG_TIMER
cmd.scan_begin_arg = int(1e9/freq)
cmd.convert_src = c.TRIG_TIMER
cmd.convert_arg = 0
cmd.scan_end_src = c.TRIG_COUNT
cmd.scan_end_arg = nchans
cmd.stop_src = c.TRIG_NONE
cmd.stop_arg = 0
cmd.chanlist = channel_config
cmd.chanlist_len = nchans
ret = self.test_cmd(cmd)
if ret !=0:
self.logger.error("Error preparing command")
return -1
return cmd
def streamer(device,subdevice,chans,comedi_range,shared_array):
''' read the channels defined in chans, on the device/subdevice, and streams the values in the shared_array.
The shared_array has a lock, to avoid reading and writing at the same time and it's process-proof.
device: '/dev/comedi0'
subdevice : 0=in, 1=out
chans : [0,1,2,3,4....] : BE AWARE the reading is done crescendo, no matter the order given here. It means that [0,1,2] and [2,0,1] will both have [0,1,2] as result, but you can ask for [0,1,5].
comedi_range: same size as chans, with the proper range for each chan. If unknown, try [0,0,0,....].
shared_array: same size as chans, must be defined before with multiprocess.Array: shared_array= Array('f', np.arange(len(chans)))
'''
dev=c.comedi_open(device)
if not dev: raise "Error openning Comedi device"
fd = c.comedi_fileno(dev) #get a file-descriptor for use later
BUFSZ = 10000 #buffer size
freq=8000# acquisition frequency: if too high, set frequency to maximum.
nchans = len(chans) #number of channels
aref =[c.AREF_GROUND]*nchans
mylist = c.chanlist(nchans) #create a chanlist of length nchans
maxdata=[0]*(nchans)
range_ds=[0]*(nchans)
for index in range(nchans): #pack the channel, gain and reference information into the chanlist object
mylist[index]=c.cr_pack(chans[index], comedi_range[index], aref[index])
maxdata[index]=c.comedi_get_maxdata(dev,subdevice,chans[index])
range_ds[index]=c.comedi_get_range(dev,subdevice,chans[index],comedi_range[index])
cmd = c.comedi_cmd_struct()
period = int(1.0e9/freq) # in nanoseconds
ret = c.comedi_get_cmd_generic_timed(dev,subdevice,cmd,nchans,period)
if ret: raise "Error comedi_get_cmd_generic failed"
cmd.chanlist = mylist # adjust for our particular context
cmd.chanlist_len = nchans
cmd.scan_end_arg = nchans
cmd.stop_arg=0
cmd.stop_src=c.TRIG_NONE
t0 = time.time()
j=0
ret = c.comedi_command(dev,cmd)
if ret !=0: raise "comedi_command failed..."
#Lines below are for initializing the format, depending on the comedi-card.
data = os.read(fd,BUFSZ) # read buffer and returns binary data
data_length=len(data)
#print maxdata
#print data_length
if maxdata[0]<=65536: # case for usb-dux-D
n = data_length/2 # 2 bytes per 'H'
format = `n`+'H'
elif maxdata[0]>65536: #case for usb-dux-sigma
n = data_length/4 # 2 bytes per 'H'
format = `n`+'I'
#print struct.unpack(format,data)
# init is over, start acquisition and stream
last_t=time.time()
try:
while True:
#t_now=time.time()
#while (t_now-last_t)<(1./frequency):
#t_now=time.time()
##print t_now-last_t
#last_t=t_now
data = os.read(fd,BUFSZ) # read buffer and returns binary data
#print len(data), data_length
if len(data)==data_length:
datastr = struct.unpack(format,data) # convert binary data to digital value
if len(datastr)==nchans: #if data not corrupted for some reason
#shared_array.acquire()
for i in range(nchans):
shared_array[i]=c.comedi_to_phys((datastr[i]),range_ds[i],maxdata[i])
#print datastr
#shared_array.release()
#j+=1
#print j
#print "Frequency= ",(j/(time.time()-t0))
#print np.transpose(shared_array[:])
except (KeyboardInterrupt):
c.comedi_cancel(dev,subdevice)
ret = c.comedi_close(dev)
if ret !=0: raise "comedi_close failed..."
chans= range(nchans)
gains= [ 0 for i in chans ]
aref =[c.AREF_GROUND for i in chans ]
cmdtest_messages = [
"success",
"invalid source",
"source conflict",
"invalid argument",
"argument conflict",
"invalid chanlist"]
#wrappers include a "chanlist" object (just an Unsigned Int array) for holding the chanlist information
mylist = c.chanlist(nchans) #create a chanlist of length nchans
#now pack the channel, gain and reference information into the chanlist object
#N.B. the CR_PACK and other comedi macros are now python functions
for index in range(nchans):
mylist[index]=c.cr_pack(chans[index], gains[index], aref[index])
size = c.comedi_get_buffer_size(dev, subdevice)
print "buffer size is ", size
map = mmap.mmap(fd, size, mmap.MAP_SHARED, mmap.PROT_READ)
print "map = ", map
def dump_cmd(cmd):
print "---------------------------"
print "command structure contains:"
def streamer(device, subdevice, chans, comedi_range, shared_array):
''' read the channels defined in chans, on the device/subdevice, and streams the values in the shared_array.
The shared_array has a lock, to avoid reading and writing at the same time and it's process-proof.
device: '/dev/comedi0'
subdevice : 0=in, 1=out
chans : [0,1,2,3,4....] : BE AWARE the reading is done crescendo, no matter the order given here. It means that [0,1,2] and [2,0,1] will both have [0,1,2] as result, but you can ask for [0,1,5].
comedi_range: same size as chans, with the proper range for each chan. If unknown, try [0,0,0,....].
shared_array: same size as chans, must be defined before with multiprocess.Array: shared_array= Array('f', np.arange(len(chans)))
'''
dev = c.comedi_open(device)
if not dev: raise "Error openning Comedi device"
fd = c.comedi_fileno(dev) #get a file-descriptor for use later
BUFSZ = 10000 #buffer size
freq = 8000 # acquisition frequency: if too high, set frequency to maximum.
nchans = len(chans) #number of channels
aref = [c.AREF_GROUND] * nchans
mylist = c.chanlist(nchans) #create a chanlist of length nchans
maxdata = [0] * (nchans)
range_ds = [0] * (nchans)
for index in range(
nchans
): #pack the channel, gain and reference information into the chanlist object
mylist[index] = c.cr_pack(chans[index], comedi_range[index],
aref[index])
maxdata[index] = c.comedi_get_maxdata(dev, subdevice, chans[index])
range_ds[index] = c.comedi_get_range(dev, subdevice, chans[index],
comedi_range[index])
cmd = c.comedi_cmd_struct()
period = int(1.0e9 / freq) # in nanoseconds
ret = c.comedi_get_cmd_generic_timed(dev, subdevice, cmd, nchans, period)
if ret: raise "Error comedi_get_cmd_generic failed"
cmd.chanlist = mylist # adjust for our particular context
cmd.chanlist_len = nchans
cmd.scan_end_arg = nchans
cmd.stop_arg = 0
cmd.stop_src = c.TRIG_NONE
t0 = time.time()
j = 0
ret = c.comedi_command(dev, cmd)
if ret != 0: raise "comedi_command failed..."
#Lines below are for initializing the format, depending on the comedi-card.
data = os.read(fd, BUFSZ) # read buffer and returns binary data
data_length = len(data)
#print maxdata
#print data_length
if maxdata[0] <= 65536: # case for usb-dux-D
n = data_length / 2 # 2 bytes per 'H'
format = ` n ` + 'H'
elif maxdata[0] > 65536: #case for usb-dux-sigma
n = data_length / 4 # 2 bytes per 'H'
format = ` n ` + 'I'
#print struct.unpack(format,data)
# init is over, start acquisition and stream
last_t = time.time()
try:
while True:
#t_now=time.time()
#while (t_now-last_t)<(1./frequency):
#t_now=time.time()
##print t_now-last_t
#last_t=t_now
data = os.read(fd, BUFSZ) # read buffer and returns binary data
#print len(data), data_length
if len(data) == data_length:
datastr = struct.unpack(
format, data) # convert binary data to digital value
if len(datastr
) == nchans: #if data not corrupted for some reason
#shared_array.acquire()
for i in range(nchans):
shared_array[i] = c.comedi_to_phys(
(datastr[i]), range_ds[i], maxdata[i])
#print datastr
#shared_array.release()
#j+=1
#print j
#print "Frequency= ",(j/(time.time()-t0))
#print np.transpose(shared_array[:])
except (KeyboardInterrupt):
c.comedi_cancel(dev, subdevice)
ret = c.comedi_close(dev)
if ret != 0: raise "comedi_close failed..."
#three lists containing the chans, gains and referencing
#the lists must all have the same length
chans = [0, 1, 2, 3]
gains = [0, 0, 0, 0]
aref = [c.AREF_GROUND, c.AREF_GROUND, c.AREF_GROUND, c.AREF_GROUND]
cmdtest_messages = [
"success", "invalid source", "source conflict", "invalid argument",
"argument conflict", "invalid chanlist"
]
nchans = len(chans) #number of channels
#wrappers include a "chanlist" object (just an Unsigned Int array) for holding the chanlist information
mylist = c.chanlist(nchans) #create a chanlist of length nchans
#now pack the channel, gain and reference information into the chanlist object
#N.B. the CR_PACK and other comedi macros are now python functions
for index in range(nchans):
mylist[index] = c.cr_pack(chans[index], gains[index], aref[index])
size = c.comedi_get_buffer_size(dev, subdevice)
print("buffer size is ", size)
map = mmap.mmap(fd, size, mmap.MAP_SHARED, mmap.PROT_READ)
print("map = ", map)
def dump_cmd(cmd):
print("---------------------------")
print("command structure contains:")
maxdata = c.comedi_get_maxdata(dev, 0, 0) print "Max Data: %d" % maxdata subdev = c.comedi_find_subdevice_by_type(dev, c.COMEDI_SUBD_COUNTER, 0) print "Subdevice: %d" % subdev print "Locked? %d" % c.comedi_lock(dev, subdev) nChannels = c.comedi_get_n_channels(dev, subdev) print "Num Channels: %d" % nChannels crange = c.comedi_get_range(dev, 0, 0, 0) print "Range: %s" % str(crange) params = c.chanlist(1) params[0] = 0 # configure the encoder instr = c.comedi_insn_struct() instr.insn = c.INSN_CONFIG instr.n = 1 instr.data = params instr.subdev = 5 # instr.chanspec = c.cr_pack(0,0,c.AREF_OTHER) instr.chanspec = c.cr_pack(0,0,0) ret=c.comedi_do_insn(dev,instr); print ret # Encoder read instruction */
def pci_6033e_init(self, dev_name):
self.dev = c.comedi_open(dev_name)
if not(self.dev):
self.warn_dialog("Unable to open device: " + dev_name)
return(-1)
ret = c.comedi_lock(self.dev, SUBDEVICE)
if (ret < 0):
self.warn_dialog("Could not lock comedi device")
return(-1)
# get a file-descriptor for use later
self.fd = c.comedi_fileno(self.dev)
if (self.fd <= 0):
self.warn_dialog("Error obtaining Comedi device file descriptor")
c.comedi_close(self.dev)
return(-1)
# Channel range (0-5V)
if (c.comedi_range_is_chan_specific(self.dev, SUBDEVICE) != 0):
self.warn_dialog("Comedi range is channel specific!")
c.comedi_close(self.dev)
return(-1)
self.comedi_range = c.comedi_get_range(self.dev, SUBDEVICE, 0, CHAN_RANGE)
self.comedi_maxdata = c.comedi_get_maxdata(self.dev, SUBDEVICE, 0)
board_name = c.comedi_get_board_name(self.dev)
if (board_name != "pci-6033e"):
print("Opened wrong device!")
# Prepare channels, gains, refs
self.comedi_num_chans = NUM_CHANNELS
chans = range(self.comedi_num_chans)
gains = [0]*self.comedi_num_chans
aref = [c.AREF_GROUND]*self.comedi_num_chans
chan_list = c.chanlist(self.comedi_num_chans)
# Configure all the channels!
for i in range(self.comedi_num_chans):
chan_list[i] = c.cr_pack(chans[i], gains[i], aref[i])
# The comedi command
self.cmd = c.comedi_cmd_struct()
# 1.0e9 because this number is in nanoseconds for some reason
period = int(1.0e9/float(SCAN_FREQ))
# Init cmd
ret = c.comedi_get_cmd_generic_timed(self.dev, SUBDEVICE, self.cmd, self.comedi_num_chans, period)
if (ret):
self.warn_dialog("Could not initiate command")
c.comedi_close(self.dev)
return(-1)
# Populate command
self.cmd.chanlist = chan_list
self.cmd.chanlist_len = self.comedi_num_chans
self.cmd.scan_end_arg = self.comedi_num_chans
self.cmd.stop_src = c.TRIG_NONE
self.cmd.stop_arg = 0
print("real timing: %d ns" % self.cmd.convert_arg)
print("Real scan freq: %d Hz" % (1.0/(float(self.cmd.convert_arg)*32.0*1.0e-9)))
#print("period: %d ns" % period)
print_cmd(self.cmd)
# Test command out.
ret = c.comedi_command_test(self.dev, self.cmd)
if (ret < 0):
self.warn_dialog("Comedi command test failed!")
c.comedi_close(self.dev)
return(-1)
print("Command test passed")
return(0)
def acquire_data(config):
"""
Acquire data from data acquisition device.
"""
#Open a comedi device
dev = c.comedi_open(config['device'])
if not dev:
err_msg = "%s: error: unable to open openning Comedi device" % (
PROG_NAME, )
sys.stderr.write(err_msg)
sys.exit(1)
# Get a file-descriptor to access data
fd = c.comedi_fileno(dev)
# Setup channels
nchans = len(config['channels'])
aref_str = config['aref'].lower()
if aref_str == 'diff':
aref = [c.AREF_DIFF] * nchans
elif aref_str == 'common':
aref = [c.AREF_COMMON] * nchans
elif aref_str == 'ground':
aref = [c.AREF_GROUND] * nchans
else:
raise ValueError, 'unknown aref'
#nchans = len(config['channels'])
#aref =[c.AREF_GROUND]*nchans
# Pack the channel, gain and reference information into the chanlist object
channel_list = c.chanlist(nchans)
for i in range(nchans):
channel_list[i] = c.cr_pack(config['channels'][i], config['gains'][i],
aref[i])
# Construct a comedi command
cmd = c.comedi_cmd_struct()
cmd.subdev = config['subdev']
cmd.flags = DEFAULT_CMD_FLAGS
cmd.start_src = c.TRIG_NOW
cmd.sart_arg = DEFAULT_CMD_SART_ARG
cmd.scan_begin_src = c.TRIG_TIMER
cmd.scan_begin_arg = int(NANO_SEC / config['sample_freq'])
cmd.convert_src = c.TRIG_TIMER
cmd.convert_arg = DEFAULT_CMD_CONVERT_ARG
cmd.scan_end_src = c.TRIG_COUNT
cmd.scan_end_arg = nchans
cmd.stop_src = c.TRIG_COUNT
cmd.stop_arg = config['sample_num']
cmd.chanlist = channel_list
cmd.chanlist_len = nchans
# Test comedi command
if config['verbose']:
print 'Testing comedi command'
print
for i in range(0, DEFAULT_CMD_TEST_NUM):
if config['verbose']:
print_cmd(cmd)
ret = c.comedi_command_test(dev, cmd)
if config['verbose']:
print
print '\t*** test %d returns %s' % (i, CMD_TEST_MSG[ret])
print
if not ret == 0:
msg_data = (PROG_NAME, CMD_TEST_MSG[ret])
err_msg = '%s: error: unable to configure daq device - %s' % msg_data
sys.stderr.write(err_msg)
# Acquire data
if config['verbose']:
print 'acquiring data'
print
sys.stdout.flush()
ret = c.comedi_command(dev, cmd) # non blocking
if not ret == 0:
err_msg = '%s: error: unable to execute comedi command' % (PROG_NAME, )
sys.stderr.write(err_msg)
sys.exit(1)
# Read data from buffer - may want to add a timeout here
read_done = False
bytes_total = 2 * config['sample_num'] * nchans
bytes_read = 0
datastr = ''
while not read_done:
try:
buffstr = os.read(fd, bytes_total)
except OSError, err:
if err.args[0] == 4:
continue
raise
datastr += buffstr
bytes_read += len(buffstr)
if config['verbose']:
print '\tread:', bytes_read, 'of', 2 * config[
'sample_num'] * nchans, 'bytes'
if bytes_read == bytes_total:
read_done = True
def scancommand(self, nscans=1000, chans=None, gains=None, aref=None):
"""Setup a scan
nscans: total number of scans (int)
chans: which channels (list)
gains: which gain adjustments (list)
aref: analog references (list)
The lists must all have the same length!
[sic] I think this will work but it's completely untested!
--bryan
I was not able to get this to work with my Vellemen P8061-2
board -- foley
"""
if not chans:
raise RuntimeError("No Channels given in 'chans'")
if not gains:
raise RuntimeError("No gains given in 'gains'")
if not aref:
raise RuntimeError("No analog references given in 'aref'")
if not len(chans) == len(gains) == len(aref):
raise RuntimeError(
"chans(%d), gains(%d), and aref(%d) not the same size"
% (len(chans), len(gains), len(aref)))
nchans = len(chans) # number of channels
# wrappers include a "chanlist" object (just an Unsigned Int
# array) for holding the chanlist information
mylist = c.chanlist(nchans) # create a chanlist of length nchans
# now pack the channel, gain and reference information into
# the chanlist object
# N.B. the CR_PACK and other comedi macros are now python functions
for index in range(nchans):
mylist[index] = c.cr_pack(
chans[index], gains[index], aref[index])
# construct a comedi command manually
cmd = c.cmd_struct()
cmd.subdev = 0
cmd.flags = 0
cmd.start_src = c.TRIG_NOW
cmd.sart_arg = 0
cmd.scan_begin_src = c.TRIG_TIMER
cmd.scan_begin_arg = int(1.0E9 / 100000)
cmd.convert_src = c.TRIG_TIMER
cmd.convert_arg = 1
cmd.scan_end_src = c.TRIG_COUNT
cmd.scan_end_arg = nchans
cmd.stop_src = c.TRIG_COUNT
cmd.stop_arg = nscans
cmd.chanlist = mylist
cmd.chanlist_len = nchans
dev = self.dev
# test our comedi command a few times.
ret = c.command_test(dev, cmd)
print("first cmd test returns ", ret)
ret = c.command_test(dev, cmd)
print("second test returns ", ret)
ret = c.command_test(dev, cmd)
if not ret:
raise RuntimeError("Error testing comedi command")
ret = c.command(self.dev, cmd)
chunk = 8
# chunk: how many bytes to read at a time
datalist = []
data = os.read(self.cfd, chunk)
while len(data) > 0:
datalist.append(data)
data = os.read(self.cfd, chunk)
datastr = string.join(datalist, '')
print("Data from command:")
print(datastr) # Here's your data, as a single string!
# if you've got Numeric installed you can convert data
# into a flat Numpy array with:
# dataarray = Numeric.fromstring(data, Int16)
return ret