research/TCS/interface.py

   1 #!/usr/bin/python
   2
   3 # @file "interface.py"
   4 # @author Sam Moore
   5 # @purpose AVR Butterfly Datalogger control for Total Current Spectroscopy Measurements
   6 #       The AVR responds to a limited number of RS232 commands to read ADC channels and set the DAC
   7 #       This script can be used to control the DAC and monitor initial energy & sample current over RS232
   8
   9 import sys
  10 import os
  11 import time
  12 import serial
  13 import datetime
  14
  15 import odict
  16 import Gnuplot, Gnuplot.funcutils
  17
  18 gnuplot = Gnuplot.Gnuplot()
  19
  20 # TODO: Insert variables for calibration purposes here.
  21 calibrate = {
  22         "ADC_Counts" : [2**10,2**10,2**10,2**10,2**10,2**10,2**10], # Maxed counts on ADC channels (10 bits = 2**10 = 1024)
  23         "DAC_Counts" : 2**12, # Maxed counts on DAC channel (12 bits = 2**12 = 4096)
  24
  25         # Calibration data for DAC and ADC
  26         "DAC" : None,
  27         "ADC" : [None, None, None, None, None, None, None, None],
  28
  29         # Data used for rough calibration if above data is not present
  30         "Vref" : 3.3, # The output of the voltage regulator (Vref = Vcc) relative to signal ground
  31         "ADC_Rin" : [None, None, None, None, 15000, 1100, 1100, 1100],
  32         "ADC_Rvar" : [None, None, None, None, 1000, 5000, 10000, 50000],
  33         "DAC_Gain" : 1
  34 }
  35
  36 # TODO: Adjust aqcuisition parameters here
  37 aquire = { "DAC_Sweep" : "0.0 + 50.0*int(step)", # DAC Sweep value (t is in STEPS, not seconds!)
  38         "ADC_Averages" : 200,
  39         #"ADC_Vi" : 5, # ADC channel to read back Vi (set by DAC) through
  40         #"ADC_Is" : 4, # ADC channel to read back Is through
  41         #"ADC_Ie" : 4, # ADC channel to read back Ie through
  42         "DAC_Settle" : 0.0, # Time in seconds to wait for DAC to stabilise
  43         #"response_wait" : 0.2, # Time to wait in seconds between sending data and reading back
  44         "start_date" : None,
  45         "open_files" : []
  46 }
  47
  48 #Setup the serial connection parameters
  49 ser = serial.Serial(
  50         port="/dev/ttyUSB1", # Modify as needed (note: in linux need to run `sudo chmod a+rw /dev/ttyUSBX' to set permissions)
  51
  52         # Do not change the values below here (unless AVR butterfly is reprogrammed to use different values)
  53         baudrate=4800,
  54         parity="N",
  55         stopbits=1,
  56         bytesize=8,
  57         timeout=None,
  58         xonxoff=0,
  59         rtscts=0
  60 )
  61
  62 parameters = odict.odict([
  63         ("Accelerating Voltage" , None),
  64         ("Focus Voltage" , None),
  65         ("Deflection Voltage" , None),
  66         ("Venault Voltage" , None),
  67         ("Initial Voltage" , None),
  68         ("Heating Current" , None),
  69         ("Heating Voltage" , None),
  70         ("Chamber Pressure" , None),
  71         ("610B Zero" , None),
  72         ("602 Zero" , None),
  73         ("610B Scale" , None),
  74         ("602 Scale" , None),
  75         ("602 0.1 Battery" , None),
  76         ("602 0.03 Battery" , None),
  77         ("602 0.01 Battery" , None),
  78         ("602 0.003 Battery" , None),
  79         ("602 0.001 Battery" , None),
  80         ("ADC Regulator" , None),
  81         ("Sample", None),
  82         ("Sample Angle", None),
  83         ("Title" , None),
  84         ("Comment" , None),
  85         ("Data" , None),
  86         ("Parameters last checked", None)
  87 ])
  88
  89 def getTime():
  90         return str(datetime.datetime.now()).split(" ")[1].split(".")[0].replace(":","")
  91
  92 def getDate():
  93         return str(datetime.datetime.now()).split(" ")[0]
  94
  95 # Used for when I press Control-C to stop things
  96 def set_exit_handler(func):
  97     if os.name == "nt":
  98         try:
  99             import win32api
 100             win32api.SetConsoleCtrlHandler(func, True)
 101         except ImportError:
 102             version = ".".join(map(str, sys.version_info[:2]))
 103             raise Exception("pywin32 not installed for Python " + version)
 104     else:
 105         import signal
 106         signal.signal(signal.SIGTERM, func)
 107         signal.signal(signal.SIGINT, func)
 108
 109 def killed_handler(signal, frame):
 110         reason = ""
 111         sys.stdout.write("\n# Reason for killing program? ")
 112         reason = sys.stdin.readline().strip("\r\n ")
 113         for out in aquire["open_files"]:
 114                 sys.stdout.write("# Closing file " + str(out) + "\n")
 115                 out.write("# Recieved KILL signal.\n# Reason: " + str(reason) + "\n")
 116                 log_close(out)
 117
 118
 119
 120 def cleanup():
 121         for out in aquire["open_files"]:
 122                 out.write("# Program exits.\n")
 123                 log_close(out)
 124
 125 def log_open(a, b):
 126         result = open(a, b,0)
 127         if (b == "w"):
 128                 result.write("# File opened at " + str(datetime.datetime.now()) + "\n")
 129                 aquire["open_files"].append(result)
 130         return result
 131
 132 def log_close(afile):
 133         if (afile in aquire["open_files"]):
 134                 afile.write("# File closed at " + str(datetime.datetime.now()) + "\n")
 135                 aquire["open_files"].remove(afile)
 136
 137         afile.close()
 138
 139
 140 def init():
 141         #import atexit
 142         #atexit.register(cleanup)
 143         set_exit_handler(killed_handler)
 144
 145         aquire["start_date"] = getDate()
 146
 147
 148
 149         # Connect serial
 150         ser.open()
 151         ser.isOpen()
 152 #       print("Waiting for \"# hello\" from device...")
 153 #       while (ser.readline().strip("\r\n") != "# hello"):
 154 #               pass
 155         #while (ser.readline().strip("\r\n ") != "#"):
 156         #       pass
 157         time.sleep(1.0)
 158
 159         ser.write("a "+str(aquire["ADC_Averages"]) + "\r\n")
 160         print(ser.readline().strip("\r\n"))
 161         print(ser.readline().strip("\r\n"))
 162         print(ser.readline().strip("\r\n"))
 163
 164         #print("Writing config information to config.dat...")
 165         #output = log_open("config.dat", "w", 1)
 166
 167         #output.write("# Initialise " + str(datetime.datetime.now()) + "\n")
 168
 169         #for field in calibrate:
 170         #       output.write("# calibrate["+str(field)+"] = "+str(calibrate[field]) + "\n")
 171         #output.write("\n")
 172         #for field in aquire:
 173         #       output.write("# aquire["+str(field)+"] = "+str(aquire[field]) + "\n")
 174
 175         #output.write("# Ready " + str(datetime.datetime.now()) + "\n# EOF\n")
 176         #output.close()
 177
 178 def main():
 179
 180         init()
 181
 182         # I haven't ever used calibrated results, and yet this code is still here, why???
 183         #if (loadCalibration_DAC() == False):
 184         #       if (calibrateDAC() == False):
 185         #               return -1
 186         #if (loadCalibration_ADC(aquire["ADC_Is"]) == False):
 187         #       if (calibrateADC_usingDAC(aquire["ADC_Is"], False) == False):
 188         #               if (calibrateADC(aquire["ADC_Is"]) == False):
 189         #                       return -1
 190
 191         #if (loadCalibration_ADC(aquire["ADC_Vi"]) == False):
 192         #       if (calibrateADC_usingDAC(aquire["ADC_Vi"], True) == False):
 193         #               if (calibrateADC(aquire["ADC_Vi"]) == False):
 194         #                       return -1
 195
 196
 197         # Make directory for today, backup calibration files
 198         os.system("mkdir -p " + getDate())
 199         #os.system("cp *.dat " + getDate() +"/")
 200
 201         checkList()
 202
 203
 204
 205
 206
 207         # Experiment
 208         # TODO: Modify data to record here
 209         sweep = 1
 210         while True:
 211                 os.system("mkdir -p " + getDate())
 212                 record_data([5], getDate()+"/"+str(getTime())+".dat", None, 4000)
 213                 sweep += 1
 214
 215
 216 def checkList():
 217         try:
 218                 input_file = log_open(getDate()+"/checklist", "r")
 219         except:
 220                 input_file = None
 221
 222         if (input_file != None):
 223                 for line in input_file:
 224                         k = line.split("=")
 225                         item = None
 226                         if (len(k) >= 2):
 227                                 item = k[0].strip("# \r\n")
 228                                 value = k[1].strip("# \r\n")
 229
 230                         if (item in parameters):
 231                                 parameters[item] = value
 232
 233                 print("Checklist found. Overwrite? [Y/n]")
 234                 response = sys.stdin.readline().strip(" \r\n")
 235                 if (response == "" or response == "y" or response == "Y"):
 236                         input_file = log_open(getDate()+"/checklist.old", "w")
 237                         for item in parameters:
 238                                 input_file.write("# " + str(item) + " = " + str(parameters[item]) + "\n")
 239                         input_file.write("\n")
 240                         log_close(input_file)
 241                         input_file = None
 242
 243         if (input_file == None):
 244                 for item in parameters:
 245                         if item == "Parameters last checked":
 246                                 continue
 247                         sys.stdout.write("\""+str(item)+"\" = " + str(parameters[item]) + " New value?: ")
 248                         response = sys.stdin.readline().strip("\r\n ")
 249                         if (response != ""):
 250                                 parameters[item] = response
 251                         sys.stdout.write("\n")
 252                 parameters["Parameters last checked"] = str(datetime.datetime.now())
 253
 254
 255         checklist = log_open(getDate()+"/checklist", "w")
 256         for item in parameters:
 257                 checklist.write("# "+str(item) + " = " + str(parameters[item]) + "\n")
 258                 #output_file.write("# "+str(item) + " = " + str(parameters[item]) + "\n")
 259         log_close(checklist)
 260
 261
 262 def record_data(ADC_channels, output, pollTime = None, dac_max = None):
 263
 264         if (output != None):
 265                 gnuplot("set title \""+str(output)+"\"")
 266                 output = [log_open(output, "w"), sys.stdout]
 267
 268         else:
 269                 gnuplot("set title \"<No file>\"")
 270                 output = [sys.stdout]
 271
 272         for field in aquire:
 273                 for out in output:
 274                         out.write("# aquire["+str(field)+"] = "+str(aquire[field]) + "\n")
 275
 276         for out in output:
 277                 out.write("# Parameters:\n")
 278
 279         for field in parameters:
 280                 for out in output:
 281                         out.write("# "+str(field)+" = " + str(parameters[field]) + "\n")
 282
 283
 284         start_time = time.time()
 285
 286         gnuplot("set xlabel \"DAC (counts)\"")
 287         gnuplot("set ylabel \"ADC (counts)\"")
 288
 289
 290         for out in output:
 291                 out.write("\n")
 292                 out.write("# Experiment " + str(datetime.datetime.now()) + "\n")
 293                 out.write("# Polling for " + str(pollTime) + "s.\n")
 294                 out.write("\n")
 295                 out.write("# Data:\n")
 296                 out.write("# time\tDAC")
 297                 for channel in ADC_channels:
 298                         out.write("\tADC"+str(channel))
 299                 out.write("\n")
 300
 301         step = 0
 302         data = [] # Keep track of data for dynamic plotting
 303         dacValue = int(eval(aquire["DAC_Sweep"]))
 304         if (setDAC(dacValue) == False):
 305                 setDAC(dacValue)
 306         time.sleep(2.0)
 307         while (pollTime == None or time.time() < start_time + pollTime):
 308                 if (aquire["DAC_Sweep"] != None):
 309                         nextDacValue = int(eval(aquire["DAC_Sweep"]))
 310                         if (nextDacValue != dacValue):
 311                                 dacValue = nextDacValue
 312                                 if (dacValue < 0):
 313                                         break
 314                                 setDAC(dacValue)
 315                         step += 1
 316
 317
 318                 if (dac_max != None and dacValue >= dac_max):
 319                         break
 320
 321                 measure_start = time.time()
 322
 323                 raw_adc = []
 324
 325                 for channel in ADC_channels:
 326                         read = readADC(channel)
 327                         if read == False:
 328                                 for out in output:
 329                                         print("# Abort data collection due to failed ADC read")
 330                                         if out != sys.stdout:
 331                                                 log_close(out)
 332                                         return False
 333                         raw_adc.append((channel, read[0], read[1]))
 334
 335                 end_time = time.time()
 336
 337                 for out in output:
 338                         measure_time = measure_start + (end_time - measure_start)/2.0 - start_time
 339                         out.write(str(measure_time))
 340                         out.write("\t"+str(dacValue))
 341                         data.append([measure_time, dacValue])
 342
 343                         for adc in raw_adc:
 344                                 out.write("\t" + str(adc[1]) + "\t" + str(adc[2]))
 345                                 data[len(data)-1].append(adc[1])
 346                                 data[len(data)-1].append(adc[2])
 347                         out.write("\n")
 348
 349
 350                 gnuplot.plot(Gnuplot.Data(data, title="t = "+str(measure_time), with_="lp", using="2:3"))
 351         for out in output:
 352                 if out != sys.stdout:
 353                         log_close(out)
 354         return True
 355
 356 def loadCalibration_ADC(channel):
 357         try:
 358                 input_file = log_open("calibrateADC"+str(channel)+".dat")
 359         except:
 360                 print("Couldn't find calibration file for ADC " + str(channel))
 361                 return False
 362
 363         calibrate["ADC"][channel] = []
 364         for l in input_file:
 365                 l = l.split("#")[0].strip("\r\n ")
 366                 if (l == ""):
 367                         continue
 368                 else:
 369                         split_line = l.split("\t")
 370                         calibrate["ADC"][channel].append((float(split_line[0]), float(split_line[1])))
 371         log_close(input_file)
 372
 373         if (len(calibrate["ADC"][channel]) <= 0):
 374                 print("Empty calibration file for ADC " + str(channel))
 375                 return False
 376         return True
 377
 378 def loadCalibration_DAC():
 379         try:
 380                 input_file = log_open("calibrateDAC.dat")
 381         except:
 382                 print("Couldn't find calibration file for DAC")
 383                 return False
 384
 385         calibrate["DAC"] = []
 386         for l in input_file:
 387                 #print("Line is: "+str(l))
 388                 l = l.split("#")[0].strip("\r\n ")
 389                 if (l == ""):
 390                         continue
 391                 else:
 392                         split_line = l.split("\t")
 393                         if (len(split_line) >= 3):
 394                                 calibrate["DAC"].append((int(split_line[0]), float(split_line[1]), float(split_line[2])))
 395                         else:
 396                                 calibrate["DAC"].append((int(split_line[0]), float(split_line[1])))
 397
 398
 399         log_close(input_file)
 400
 401         if (len(calibrate["DAC"]) <= 0):
 402                 print("Empty calibration file for DAC")
 403                 return False
 404         return True
 405
 406 def getADC_Voltage(channel, counts):
 407         if (calibrate["ADC"][channel] == None or len(calibrate["ADC"][channel]) <= 0):
 408                 if (calibrate["ADC_Rin"][channel] != None and calibrate["ADC_Rvar"][channel] != None):
 409                         print("Warning: Using rough calibration for ADC"+str(channel) + " = " + str(counts))
 410                         ratio = float(calibrate["ADC_Rin"][channel]) / (float(calibrate["ADC_Rin"][channel]) + float(calibrate["ADC_Rvar"][channel]))
 411                         return ratio * (float(counts) / float(calibrate["ADC_Counts"][channel]) * Vref)
 412                 else:
 413                         print("Error: No calibration for ADC"+str(channel))
 414                         return False
 415
 416         c = calibrate["ADC"][channel]
 417         valueIndex = 1
 418         for i in range(0, len(c)-1):
 419                 if (c[i][0] <= counts and i + 1 < len(c)):
 420                         grad = (float(c[i+1][valueIndex]) - float(c[i][valueIndex])) / (float(c[i+1][0]) - float(c[i][0]))
 421                         value = float(c[i][valueIndex]) + grad * (float(counts) - float(c[i][0]))
 422                         return value
 423
 424
 425         print("Warning: Extrapolating outside calibration range for DAC = " + str(counts))
 426
 427         grad = (float(c[len(c)-1][valueIndex]) - float(c[len(c)-2][valueIndex])) / (float(c[len(c)-1][0]) -  float(c[len(c)-2][0]))
 428         value = float(c[len(c)-1][valueIndex]) + grad * (float(counts) - float(c[len(c)-1][0]))
 429
 430 def readADC(channel):
 431         #for i in range(0, aquire["ADC_Averages"]):
 432         #       ser.write("r "+str(channel)+"\r") # Send command to datalogger
 433                 #time.sleep(aquire["response_wait"])
 434         #       response = ser.readline().strip("#\r\n ")
 435         #       if (response != "r "+str(channel)):
 436         #               print("Received wierd response reading ADC ("+response+")")
 437         #               return False
 438                 #time.sleep(aquire["response_wait"])
 439         #       values.append(int(ser.readline().strip("\r\n ")))
 440         #       adc_sum += float(values[len(values)-1])
 441         ser.write("r "+str(channel)+"\r")
 442         response = ser.readline().strip("#\r\n")
 443         if (response != "r "+str(channel)):
 444                 print("Received wierd response reading ADC ("+response+")")
 445                 return False
 446         return ser.readline().strip("\r\n").split(" ")
 447
 448 def getDAC_Voltage(counts, gain = True):
 449         if (calibrate["DAC"] == None or len(calibrate["DAC"]) <= 0):
 450                 if (calibrate["DAC_Gain"] != None):
 451                         print("Warning: Using rough calibration for DAC = " + str(counts))
 452                         return float(counts) / float(calibrate["DAC_Counts"]) * float(calibrate["Vref"]) * float(calibrate["DAC_Gain"])
 453                 else:
 454                         print("Error: No calibrate for DAC")
 455                         return False
 456
 457         valueIndex = 1
 458         if (gain == False):
 459                 valueIndex = 2
 460                 if (len(calibrate["DAC"][0]) < 3):
 461                         print("Error: No data for unamplified DAC")
 462                         return False
 463
 464         c = calibrate["DAC"]
 465         if (len(c) == 1):
 466                 print("Warning: Only one point in calibration data!")
 467                 return float(c[0][valueIndex])
 468
 469         for i in range(0, len(c)-1):
 470                 if (c[i][0] <= counts and i + 1 < len(c)):
 471                         grad = (float(c[i+1][valueIndex]) - float(c[i][valueIndex])) / (float(c[i+1][0]) - float(c[i][0]))
 472                         value = float(c[i][valueIndex]) + grad * (float(counts) - float(c[i][0]))
 473                         return value
 474
 475
 476         print("Warning: Extrapolating outside calibration range for DAC = " + str(counts))
 477
 478         grad = (float(c[len(c)-1][valueIndex]) - float(c[len(c)-2][valueIndex])) / (float(c[len(c)-1][0]) -  float(c[len(c)-2][0]))
 479         value = float(c[len(c)-1][valueIndex]) + grad * (float(counts) - float(c[len(c)-1][0]))
 480         return value
 481
 482
 483 def setDAC(level):
 484
 485         ser.write("d "+str(level)+"\r")
 486
 487         response = ser.readline().strip("#\r\n ")
 488         if (response != "d "+str(level)):
 489                 print("Recieved wierd response setting DAC to "+str(level) + " ("+response+")")
 490                 return False
 491         #time.sleep(aquire["response_wait"])
 492         #time.sleep(aquire["DAC_Settle"])
 493         #time.sleep(aquire["DAC_Settle"])
 494         response = ser.readline().strip("#\r\n ")
 495         if (response != "DAC "+str(level)):
 496                 print("Recieved wierd response setting DAC to "+str(level) + " ("+response+")")
 497                 return False
 498         #time.sleep(aquire["response_wait"])
 499         time.sleep(aquire["DAC_Settle"])
 500
 501
 502 def calibrateADC_usingDAC(channel, gain = True):
 503         if (calibrate["DAC"] == None):
 504                 print("ERROR: DAC is not calibrated, can't use to calibrate ADC!")
 505                 return False
 506
 507         calibrate["ADC"][channel] = []
 508         outfile = log_open("calibrateADC"+str(channel)+".dat", "w")
 509         outfile.write("# Calibrate ADC " + str(channel) + "\n")
 510         outfile.write("# Start " + str(datetime.datetime.now()) + "\n")
 511
 512         print("Connect DAC output to ADC " + str(channel) + " and press enter\n")
 513         sys.stdin.readline()
 514
 515         for dac in calibrate["DAC"]:
 516                 if (setDAC(dac[0]) == False):
 517                         return False
 518
 519                 value = readADC(channel)
 520                 if (value == False):
 521                         return False
 522                 canadd = (len(calibrate["ADC"][channel]) <= 0)
 523                 if (canadd == False):
 524                         canadd = True
 525                         for adc in calibrate["ADC"][channel]:
 526                                 if adc[0] == value[0]:
 527                                         canadd = False
 528                                         break
 529
 530                 if (canadd):
 531
 532                         if gain:
 533                                 input_value = dac[1]
 534                         else:
 535                                 input_value = dac[2]
 536
 537                         #input_value = getDAC_Voltage(dac[0], gain)
 538                         if (input_value == False):
 539                                 return False
 540
 541                         outfile.write(str(value[0]) + "\t" + str(input_value) + "\t" + str(value[1]) + "\n")
 542                         print(str(value[0]) + "\t" + str(input_value) + "\t" + str(value[1]))
 543
 544                         calibrate["ADC"][channel].append((value[0], input_value, value[1]))
 545
 546         outfile.write("# Stop " + str(datetime.datetime.now()) + "\n# EOF\n")
 547         log_close(outfile)
 548         if (setDAC(0) == False):
 549                 return False
 550         if (len(calibrate["ADC"][channel]) <= 0):
 551                 print("Error: No calibration points taken for ADC " + str(channel))
 552                 return False
 553         return True
 554
 555 def calibrateADC(channel):
 556         calibrate["ADC"][channel] = []
 557         outfile = log_open("calibrateADC"+str(channel)+".dat", "w")
 558         outfile.write("# Calibrate ADC " + str(channel) + "\n")
 559         outfile.write("# Start " + str(datetime.datetime.now()) + "\n")
 560
 561         print("Calibrating ADC...\n")
 562         print("Enter measured voltage, empty line stops.\n")
 563
 564         while True:
 565                 read = sys.stdin.readline().strip("\r\n ")
 566                 if (read == ""):
 567                         break
 568                 input_value = float(read)
 569                 output_value = readADC(channel)
 570                 if (output_value == False):
 571                         return False
 572
 573                 calibrate["ADC"][channel].append((output_value[0], input_value))
 574                 print(str(output_value[0]) + "\t" + str(input_value))
 575
 576         calibrate["ADC"][channel].sort(lambda e : e[1], reverse = False)
 577
 578
 579
 580
 581         outfile.write("# Stop " + str(datetime.datetime.now()) + "\n# EOF\n")
 582         log_close(outfile)
 583         if (len(calibrate["ADC"][channel]) <= 0):
 584                 print("Error: No calibration points taken for ADC " + str(channel))
 585                 return False
 586
 587         return True
 588
 589 def calibrateDAC():
 590         calibrate["DAC"] = []
 591
 592         outfile = log_open("calibrateDAC.dat", "w")
 593         outfile.write("# Calibrate DAC\n")
 594         outfile.write("# Start " + str(datetime.datetime.now()) + "\n")
 595
 596         print("Calibrating DAC...")
 597         sys.stdout.write("Number of counts to increment per step: ")
 598         read = sys.stdin.readline().strip("\r\n")
 599         if (read == ""):
 600                 return False
 601         stepSize = max(1, int(read))
 602         sys.stdout.write("\n")
 603
 604         outfile.write("# Increment by " + str(stepSize) + "\n")
 605         print("Input measured DAC voltage for each level; empty input ends calibration.")
 606         print("You may optionally input the DAC voltage before it is amplified too.")
 607
 608         level = 0
 609         while (level < calibrate["DAC_Counts"]):
 610
 611                 setDAC(level)
 612
 613                 sys.stdout.write(str(level) + " ?")
 614                 read = sys.stdin.readline().strip("\r\n ")
 615                 if (read == ""):
 616                         break
 617                 else:
 618                         read = read.split(" ")
 619                         if (len(calibrate["DAC"]) > 0 and len(calibrate["DAC"][len(calibrate["DAC"])-1]) != len(read)):
 620                                 print("Either give one value for EVERY point, or two values for EVERY point. Don't mess around.")
 621                                 return False
 622                         if (len(read) == 2):
 623                                 calibrate["DAC"].append((level, float(read[0]), float(read[1])))
 624                                 outfile.write(str(level) + "\t" + str(float(read[0])) + "\t" + str(float(read[1])) + "\n")
 625                         else:
 626                                 calibrate["DAC"].append((level, float(read[0])))
 627                                 outfile.write(str(level) + "\t" + str(float(read[0])) + "\n")
 628
 629
 630
 631                 level += stepSize
 632
 633         outfile.write("# Stop " + str(datetime.datetime.now()) + "\n# EOF\n")
 634         log_close(outfile)
 635         if (len(calibrate["DAC"]) <= 0):
 636                 print("Error: No calibration points taken for DAC")
 637                 return False
 638         return setDAC(0)
 639
 640 # Run the main function
 641 if __name__ == "__main__":
 642         sys.exit(main())