from matplotlib.backends.backend_wxagg import Toolbar, FigureCanvasWxAgg from matplotlib.figure import Figure import comedi #@UnresolvedImport import matplotlib import numpy import os import struct import sys import threading import wx.lib.newevent import time matplotlib.use("WXAgg") matplotlib.interactive(True) ID_STARTBUTTON = 101 ID_STOPBUTTON = 102 ID_CLEARBUTTON = 103 ID_OKBUTTON = 104 ID_CONFIGUREBUTTON = 105 #default parameters DEVICE = '/dev/comedi0' NBCHANS = 2 CHANS = [0, 1] RANGES = [0, 0] REFS = [comedi.AREF_GROUND, comedi.AREF_GROUND] SAMPLE_FREQ = 1000 #global variables BUFFER_SIZE = 1000 PLOT_BUFFER_SIZE = 5000 DEBUG = True def deinterleaveData(inData, nChan): ''' takes a linear array with data points interleaved [a1,b1,c1,a2,b2,c2,....aN-1,bN-1,cN-1,aN,bN] and return a (nChan,N) numpy.array with the data deinterleaved [[a1,a2,a3,...aN-1], [b1,b2,b3,...bN-1], [c1,c2,c3,...cN-1]] if the length of the input array was not a multiple of nChan, the remaining points are returned in remainData. Otherwise, remainData is an empty array ''' n = len(inData) nToKeep = n-(n % nChan) outData = numpy.array(inData[:nToKeep],dtype=int).reshape((-1,nChan)).transpose() remainData = inData[nToKeep:] return outData,remainData def convertInVolts(inData, dev, subdev, chans, inRanges): ''' converts the int values obtained from comedi to a physical value arguments: inData: a (nChan,N) numpy array dev: the comedi device used to obtain the data subdev: the comedi subdevice used to obtain the data chans: a (nChan,1) array containing the channels from which the data was obtained inRanges: a (nChan,1) array containing the id of the chanRange used for each channel. the actual chanRange will be obtained from comedi using comedi_get_range() ''' nChan,_ = inData.shape maxDatas = [] physicalRanges = [] for chan,chanRange in zip(chans,inRanges): maxDatas.append(comedi.comedi_get_maxdata(dev,subdev,chan)) physicalRanges.append(comedi.comedi_get_range(dev,subdev,chan,chanRange)) out = numpy.array(inData,dtype=float) for i in range(nChan): out[i] = out[i]*((float(physicalRanges[i].max)-float(physicalRanges[i].min))/float(maxDatas[i])) + float(physicalRanges[i].min) return out # this creates an UpdateCanvasEvent even class that will get created # and sent from the worker thread to the main thread (which is the # only place that updates to the GUI should happen...lest there be crashes) (UpdateCanvasEvent, EVT_UPDATE_CANVAS) = wx.lib.newevent.NewEvent() class MainWindow(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, -1, "Free Period Calculation") self.arrayLock = threading.Semaphore(1) self.canvasLock = threading.Semaphore(1) self.dev = None self.subdev = None self.nbChans = NBCHANS #create the preferences window self.prefwindow = self.createPreferencesWindow() #get default configuration self.configuration = self.prefwindow.getConfiguration() self.figure = Figure((5, 4), 75) self.canvas = FigureCanvasWxAgg(self, -1, self.figure) self.toolbar = Toolbar(self.canvas) self.toolbar.Realize() self.sizerHoriz = wx.BoxSizer(wx.HORIZONTAL) self.startButton = wx.Button(self, ID_STARTBUTTON, "Start") wx.EVT_BUTTON(self, ID_STARTBUTTON, self.pressStartButton); self.stopButton = wx.Button(self, ID_STOPBUTTON, "Stop") self.stopButton.Enable(0) wx.EVT_BUTTON(self, ID_STOPBUTTON, self.pressStopButton); self.clearButton = wx.Button(self, ID_CLEARBUTTON, "Clear") wx.EVT_BUTTON(self, ID_CLEARBUTTON, self.pressClearButton); self.prefButton = wx.Button(self, ID_CONFIGUREBUTTON, "Configure") wx.EVT_BUTTON(self, ID_CONFIGUREBUTTON, self.pressConfigureButton) self.sizerHoriz.Add(self.startButton, 0, wx.ALL, 5) self.sizerHoriz.Add(self.stopButton, 0, wx.ALL, 5) self.sizerHoriz.Add(self.clearButton, 0, wx.ALL, 5) self.sizerHoriz.Add(self.prefButton, 0, wx.ALL, 5) # Use some sizers to see layout options self.sizerVert = wx.BoxSizer(wx.VERTICAL) self.sizerVert.Add(self.sizerHoriz, 0, wx.EXPAND) self.sizerVert.Add(self.canvas, 1, wx.EXPAND) self.sizerVert.Add(self.toolbar, 0, wx.GROW) #Bind the update canvas event to some function: self.Bind(EVT_UPDATE_CANVAS, self.onUpdateCanvas) self.Bind(wx.EVT_CLOSE, self.onCloseWindow) #Layout sizers self.SetSizer(self.sizerVert) self.SetAutoLayout(1) self.sizerVert.Fit(self) self.initialize() self.Show(1) def GetToolBar(self): return self.toolbar def pressStartButton(self, event): if DEBUG: print "Start button has been pressed" self.startButton.Enable(0) self.prefButton.Enable(0) self.configuration = self.prefwindow.getConfiguration() #configure the comedi device self.dev = comedi.comedi_open(str(self.configuration['device'])) if not self.dev: print "FATAL ERROR: cannot open comedi device %s: %s"%\ (self.configuration['device'], comedi.comedi_strerror(comedi.comedi_errno())) sys.exit(1) #and get an appropriate subdevice self.subdev = comedi.comedi_find_subdevice_by_type(self.dev, comedi.COMEDI_SUBD_AI, 0) if self.subdev<0: print "FATAL ERROR: cannot find a suitable analog input subdevice: %s" %\ comedi.comedi_strerror(comedi.comedi_errno()) sys.exit(1) #create channel list myChanList = comedi.chanlist(self.nbChans) for i in range(self.nbChans): myChanList[i] = comedi.cr_pack(self.configuration['analog'][i][0], self.configuration['analog'][i][1], self.configuration['analog'][i][2]) #create a command structure cmd = comedi.comedi_cmd_struct() ret = comedi.comedi_get_cmd_generic_timed(self.dev, self.subdev, cmd, self.nbChans, int(1e9 / SAMPLE_FREQ)) if ret: raise Exception("Error comedi_get_cmd_generic failed") cmd.chanlist = myChanList # adjust for our particular context cmd.chanlist_len = self.nbChans cmd.scan_end_arg = self.nbChans cmd.stop_src = comedi.TRIG_NONE #never stop #test our comedi command a few times. ret = 0 for i in range(2): ret = comedi.comedi_command_test(self.dev, cmd) if ret < 0: raise Exception("comedi_command_test failed: %s" % (comedi.comedi_strerror(comedi.comedi_errno()))) #Start the command ret = comedi.comedi_command(self.dev, cmd) if ret <> 0: raise Exception("comedi_command failed... %s" % (comedi.comedi_strerror(comedi.comedi_errno()))) #start reader thread if DEBUG: print "creating reader thread" self.helper = plotterThread(self, self.dev, self.subdev, [self.configuration['analog'][0][0],self.configuration['analog'][1][0]], [self.configuration['analog'][0][1],self.configuration['analog'][1][1]]) self.helper.start() self.stopButton.Enable(1) if DEBUG: print "Start button complete." def pressStopButton(self, event): self.stopButton.Enable(0) if self.helper is not None: self.helper.reading = False self.helper.join() if DEBUG: print "Background thread stopped." self.helper = None comedi.comedi_cancel(self.dev,self.subdev) self.startButton.Enable(1) self.prefButton.Enable(1) def pressClearButton(self, event): self.arrayLock.acquire() self.currPos = 0 self.yarray = numpy.zeros((self.nbChans,PLOT_BUFFER_SIZE)) self.trigPlot.cla() self.lines = self.trigPlot.plot(self.yarray.transpose(), '-') #self.trigPlot.autoscale(True,'y') #does not work self.arrayLock.release() evt = UpdateCanvasEvent() wx.PostEvent(self, evt) def pressConfigureButton(self, event): self.prefwindow.Show(1) self.prefwindow.MakeModal(1) def initialize(self): self.trigPlot = self.figure.add_subplot(111) self.pressClearButton(None) def addData(self, inData): if DEBUG: print "#### in addData() ####" self.arrayLock.acquire() _, nbPoints = inData.shape if DEBUG: print "received %d data points. current pos in buffer: %s"%(nbPoints,self.currPos) maxPoints = PLOT_BUFFER_SIZE-self.currPos if nbPoints<=maxPoints: maxPoints = nbPoints if DEBUG: print "will add %d points to the buffer"%(maxPoints) self.yarray[:,self.currPos:(self.currPos+maxPoints)] = inData[:,:maxPoints] self.currPos += maxPoints if DEBUG: print "current position in the buffer is now %d"%(self.currPos) if self.currPos>PLOT_BUFFER_SIZE-1: #we've filled the whole buffer, we need to wrap around if DEBUG: print "wrapping around..." _,nPointsLeft = inData[:,maxPoints:].shape if DEBUG: print "we have %s points left to add to the beginning of the buffer"%nPointsLeft self.yarray[:,:nPointsLeft] = inData[:,maxPoints:] self.currPos = nPointsLeft for i in range(len(self.lines)): self.lines[i].set_data(numpy.linspace(1,PLOT_BUFFER_SIZE,PLOT_BUFFER_SIZE),self.yarray[i,:].tolist()) self.arrayLock.release() def onUpdateCanvas(self, evt): if DEBUG: print "Updating the canvas..." self.canvasLock.acquire() self.canvas.draw() #self.trigPlot.autoscale_view(None, False, True) #does not work self.toolbar.update() self.canvasLock.release() def onCloseWindow(self, evt): self.pressStopButton(evt) self.Destroy() def createPreferencesWindow(self): prefwindow = PreferencesFrame(self, "preferences") prefwindow.CentreOnParent(wx.BOTH) return prefwindow class plotterThread(threading.Thread): def __init__(self, window, dev, subdev, chans, ranges): if DEBUG: print "in plotterThread __init__" threading.Thread.__init__(self) self.window = window self.dev = dev self.subdev = subdev self.chans = chans self.ranges = ranges #get a file-descriptor for reading self.fd = comedi.comedi_fileno(self.dev) if self.fd <= 0: raise Exception("Error obtaining Comedi device file descriptor: %s" % (comedi.comedi_strerror(comedi.comedi_errno()))) self.nbChans = len(chans) self.reading = False self.currPos = 0 def run(self): if DEBUG: print "Reader thread running..." self.reading = True while (self.reading): data=None n=0 try: if DEBUG: print "reading..." data = os.read(self.fd,BUFFER_SIZE) n = len(data)/2 # 2 bytes per 'H' if DEBUG: print "read %d data points"%n if DEBUG: print "unpacking..." data = struct.unpack('%dH'%n,data) if DEBUG: print "de-interleaving..." out,data = deinterleaveData(data,self.nbChans) if DEBUG: print "returned a (%d,%d) array and kept %d for next round"%(out.shape[0],out.shape[1],len(data)) if DEBUG: print "transforming into physical units" out = convertInVolts(out,self.dev,self.subdev,self.chans,self.ranges) self.window.addData(out) evt = UpdateCanvasEvent() wx.PostEvent(self.window, evt) time.sleep(0.1) except IOError: raise Exception("Fatal Error: %s"%(comedi.comedi_strerror(comedi.comedi_errno()))) class PreferencesFrame(wx.Frame): def __init__(self, parent, title): wx.Frame.__init__(self, parent, -1, title) #p = wx.Panel(self, -1) vertSizer = wx.BoxSizer(wx.VERTICAL) titleLabel = wx.StaticText(self, -1, "Comedi Configuration") okButton = wx.Button(self, ID_OKBUTTON, "Save Changes") wx.EVT_BUTTON(self, ID_OKBUTTON, self.PressOkButton) sizer = wx.GridSizer(6, 2, 2, 2) #rows, columns, hgap, vgap vertSizer.Add(titleLabel, 0, wx.ALIGN_CENTER | wx.ALL, 8) vertSizer.Add(sizer) vertSizer.Add(okButton, 0, wx.ALIGN_RIGHT | wx.ALL, 15) deviceNameLabel = wx.StaticText(self, -1, "Device: ") self.deviceNameTextBox = wx.TextCtrl(self, -1, "/dev/comedi0") sizer.Add(deviceNameLabel, 0, wx.ALIGN_RIGHT) sizer.Add(self.deviceNameTextBox) xInputLabel = wx.StaticText(self, -1, "X Input Channel: ") self.xInputBox = wx.Choice(self, -1, choices=['0', '1', '2', '3', '4', '5', '6', '7']) self.xInputBox.SetSelection(0) sizer.Add(xInputLabel, 0, wx.ALIGN_RIGHT) sizer.Add(self.xInputBox) xInputRangeLabel = wx.StaticText(self, -1, "X Input Range: ") self.xInputRangeBox = wx.Choice(self, -1, choices=['0', '1', '2', '3']) self.xInputRangeBox.SetSelection(1) sizer.Add(xInputRangeLabel, 0, wx.ALIGN_RIGHT) sizer.Add(self.xInputRangeBox) xInputTypeLabel = wx.StaticText(self, -1, "X Input Type: ") self.xInputTypeBox = wx.Choice(self, -1, choices=['AREF_GROUND', 'AREF_COMMON', 'AREF_DIFF']) self.xInputTypeBox.SetSelection(2) sizer.Add(xInputTypeLabel, 0, wx.ALIGN_RIGHT) sizer.Add(self.xInputTypeBox) yInputLabel = wx.StaticText(self, -1, "Y Input Channel: ") self.yInputBox = wx.Choice(self, -1, choices=['0', '1', '2', '3', '4', '5', '6', '7']) self.yInputBox.SetSelection(1) sizer.Add(yInputLabel, 0, wx.ALIGN_RIGHT) sizer.Add(self.yInputBox) yInputRangeLabel = wx.StaticText(self, -1, "Y Input Range: ") self.yInputRangeBox = wx.Choice(self, -1, choices=['0', '1', '2', '3']) self.yInputRangeBox.SetSelection(1) sizer.Add(yInputRangeLabel, 0, wx.ALIGN_RIGHT) sizer.Add(self.yInputRangeBox) yInputTypeLabel = wx.StaticText(self, -1, "Y Input Type: ") self.yInputTypeBox = wx.Choice(self, -1, choices=['AREF_GROUND', 'AREF_COMMON', 'AREF_DIFF']) self.yInputTypeBox.SetSelection(2) sizer.Add(yInputTypeLabel, 0, wx.ALIGN_RIGHT) sizer.Add(self.yInputTypeBox) inputPeriodLabel = wx.StaticText(self, -1, "Samples per second: ") self.inputPeriodBox = wx.TextCtrl(self, -1, "3000") sizer.Add(inputPeriodLabel, 0, wx.ALIGN_RIGHT) sizer.Add(self.inputPeriodBox) self.SetSizer(vertSizer) self.Bind(wx.EVT_CLOSE, self.OnCloseWindow) self.Fit() def PressOkButton(self, event): self.Close(1) def OnCloseWindow(self, event): self.MakeModal(False) self.Show(0) print self.getConfiguration() #self.Destroy() def getConfiguration(self): config = dict() config["device"] = self.deviceNameTextBox.GetValue() config["analog_period_ns"] = int(1e9 / float(self.inputPeriodBox.GetValue())) x_channel = int(self.xInputBox.GetStringSelection()) x_range = int(self.xInputRangeBox.GetStringSelection()) x_aref_string = self.xInputTypeBox.GetStringSelection() x_aref=0 if x_aref_string=='AREF_GROUND': x_aref=comedi.AREF_GROUND elif x_aref_string=='AREF_COMMON': x_aref=comedi.AREF_COMMON elif x_aref_string=='AREF_DIFF': x_aref=comedi.AREF_DIFF else: x_aref=comedi.AREF_OTHER y_channel = int(self.yInputBox.GetStringSelection()) y_range = int(self.yInputRangeBox.GetStringSelection()) y_aref_string = self.yInputTypeBox.GetStringSelection() y_aref=0 if y_aref_string=='AREF_GROUND': y_aref=comedi.AREF_GROUND elif y_aref_string=='AREF_COMMON': y_aref=comedi.AREF_COMMON elif y_aref_string=='AREF_DIFF': y_aref=comedi.AREF_DIFF else: y_aref=comedi.AREF_OTHER config["analog"] = [[x_channel, x_range, x_aref], [y_channel, y_range, y_aref]] return config app = wx.PySimpleApp() frame = MainWindow() app.MainLoop()