#!/usr/bin/python
#control program for megacup aka tinman at byg.dtu.dk
# version history:
#climch2008.py 2008-12-28
# major change to weighing beam manipulation 20081124
# climch101, 22.5.2007 - program for climate chamber
# changes 08.07.2004:
# logs also strain gage input voltage, changed also climch_rc_old.py
# changes 2007: change open file directory
#
import time, string
import climch_cc # dictionary of control constants
from serport import SerialPort # serial port controller
from climch_rc import * # dictionary of data logger instructions
from climch_defs import * # calculation functions
#
# Connect to data logger
a = SerialPort("/dev/ttyS0") # set up serial port as a file
#
# Initiate history list which contains
# the present and the previous sets of data
# needed for PID (proportional) control
hist0 = [1]*20
hist1 = [1]*20
#
#Send initiation instructions
for b in InitiateMeasurements: #from climch_rc
  print b,
  a.dialog(b) #send message to serial port
  time.sleep(0.2)#gives time to check logger response

#set up the starting values
saveFlag = 1 # time to save to file
startCycle = 1# first measurement cycle
saveTime = time.time()+ 600
startPointInCycle = climch_cc.Cc['startAtTime']
timeOffset = startPointInCycle * 3600
pidTime = 60 # secs PID cycle
halfTime = pidTime/2
heat = 25 # secs warming
autoClose = 0 # set to 1 if peltier overheats
pV = climch_cc.Cc['peltierVolts']

while 1: # main loop
  try:
    now = time.time()
    # rotate cam to release weighing beam
    a.dialog('rout:open (@214)\n') #stop fan
    a.dialog('rout:clos (@215)\n') #pulse cam motor
    time.sleep(0.25) 
    a.dialog('rout:open (@215)\n')
    time.sleep(8) # wait for air and weighing beam to settle
    # is it time to save to file?
    if now > saveTime:
      # set timer to next ten minute point
      saveTime = now - (now%600) + 600
      saveFlag = 1
      reload(climch_cc) # check for new instructions
      if startPointInCycle != climch_cc.Cc['startAtTime']:
        startPointInCycle = climch_cc.Cc['startAtTime']
        timeOffset = startPointInCycle * 3600

    datestamp = time.gmtime(now)
    print 'month %s  day %s  hr %s  min %s ' % datestamp[1:5]
    if saveFlag:
      df = open('./data.txt', 'a')
      df.write('\n%s, %s, %s, %s, %s, ' % datestamp[0:5]),
      df.write( str(climch_cc.Cc['run_id'] )),
      df.write(', ')
    k = 0 # Index into hist* arrays
    hist0 = hist1[:] #overwrite older data

    a.dialog('init\n') #scan datalogger
    time.sleep(7) # scan takes some time
    # rotate cam to force water container onto heat sink
    a.dialog('rout:clos (@216)\n') #pulse motor
    time.sleep(0.25)
    a.dialog('rout:open (@216)\n')
    a.dialog('rout:clos (@214)\n') #start fan

    for b in DataMeasurements: #collect results
      c = a.dialog(b)
      s = str(c)
      num = 1.0
      if s:
        try:
          num = float(s)
          hist1[k] = num
          k = k + 1
        except ValueError, e:
          hist1[k] = ' error '
          continue

    #write some data. Note that the dewpoint in
    #hist1[1] is later overrwritten with rh
    print ' ch_t %0.1f  dp %0.1f ' % (hist1[0],hist1[1]),
    if saveFlag:
      df.write('%0.1f, %0.1f, ' % (hist1[0], hist1[1])),

    # refine data and set control values
    if startCycle: #only on the first measurement cycle
      hist0 = hist1[:] #write present data to prev data
      startCycle = 0
    tPrev = hist0[0]
    tNow = hist1[0]

    #check beam position
    if hist1[2] < 5: #beam probably in wrong position
      print 'Alert: wrong beam position, ',
      #a.dialog('rout:close (@215)\n')
      #time.sleep(2)
      #a.dialog('rout:open (@215)\n')
      hist1[2] = hist0[2] #use old data
      print 'using old data'
        
    #peltiercooling tracks dewpoint
    sink = hist1[3] - 2.0 #2.0 is the default
    print ' heatx_t %0.1f' % hist1[3],
    if sink < hist1[1]:
      a.dialog('rout:open (@207)\n')
      print ' x_cool off',
    else:
      a.dialog('rout:close (@207)\n')
      print ' x_cool on',
    

    #check for overheating
    print ' ht_snk_t %0.1f' % hist1[4]
    if hist1[4] > 35: #may need some changing in hot weather, default 30
      autoClose = 1
       
    #temperature control: set PID heating time
    thisTime = now + timeOffset
    tTarget = setTarget(thisTime,climch_cc.Cc['tPeriod'],\
      climch_cc.Cc['tAvg'],climch_cc.Cc['tHalfAmp'])
    nextTime = now + timeOffset + 60 #seconds
    tNext = setTarget(nextTime, climch_cc.Cc['tPeriod'],\
      climch_cc.Cc['tAvg'], climch_cc.Cc['tHalfAmp'])
    print ' trgt_t %0.1f' % tNext
    heat = heat + \
      piddle(tPrev, tNow, tTarget, tNext,\
        climch_cc.Cc['tCorrC'], climch_cc.Cc['tTrendC'])

    #moisture control
    rh = dpToRh(hist1[0], hist1[1])
    hist1[1] = rh
    print ' rh %i' % rh,
    # add polarity to measured Peltier V
    if pV < 0:
      hist1[5]= -hist1[5]
    print ' rh %i' % rh,
    if climch_cc.Cc['rhControl']: #RH control
      mPrev = hist0[1]
      mNow = hist1[1]
    else:                      #FLUX control
      mPrev = hist0[2]
      mNow = hist1[2]
      
    thisTime = now + timeOffset
    mTarget = setTarget(thisTime,climch_cc.Cc['mPeriod'],\
      climch_cc.Cc['mAvg'],climch_cc.Cc['mHalfAmp'])
    nextTime = now + timeOffset + 60 #seconds
    mNext = setTarget(nextTime, climch_cc.Cc['mPeriod'],\
      climch_cc.Cc['mAvg'], climch_cc.Cc['mHalfAmp'])
    print ' m_tgt %0.1f' % mNext,
    pV = pV + \
        piddle(mPrev, mNow, mTarget, mNext,\
        climch_cc.Cc['mCorrC'], climch_cc.Cc['mTrendC'])
    print ' p_volts_now %0.1f  pV_nxt %0.1f' % (hist1[5], pV),
    if autoClose:
      print 'Peltier overheating. closing...'
      pV = 0.0
    #set Peltier limits, can be changed but there is
    #a risk of overheating. Chnage only when
    #system is running reliably!
    if pV > 3.0: pV = 3.0
    if pV < (-7.0): pV = (-7.0)    
    vToB(pV, a)#sends new voltage to Peltier
    if autoClose: break #end program

    #write more values to screen and file
    print ' wt %0.2f' % hist1[2],
    print ' water_tank_t %0.1f' % hist1[8],
    print ' s.g._input_V %0.1f' % hist1[9],
    if saveFlag:
      for j in (1,2,3,4,5):
        df.write('%0.1f, ' % hist1[j]),
      #room t and rh need refining
      rm_t = thermistor(hist1[6])
      df.write('%0.1f, ' % rm_t),
      rm_m = H_RH(hist1[7], rm_t)
      df.write('%0.1f, ' % rm_m),
      #water tank temperature
      df.write('%0.1f, ' % hist1[8]),
      #strain gage input voltage, added 090104 by RHP
      #df.write('%0.1f, ' % hist1[9]),
    print ' '
  #  if saveFlag:
  #    df.write('\n')       
    saveFlag = 0
    
    #control chamber temperature
    if heat > pidTime: heat = pidTime
    if heat < (-pidTime): heat = (-pidTime)
    invHeat = pidTime - abs(heat)
    print 'INVHEAT',
    print invHeat
    timeLeft = pidTime - (time.time() - now)
    if timeLeft < 0: timeLeft = 0
    print 'TIME LEFT:',
    print timeLeft
    if heat == -pidTime: #continuous cooling
       a.dialog('rout:close (@206)\n')
       a.dialog('rout:open (@209)\n')
       print 'cooling 100%'
       time.sleep(timeLeft)
    elif heat == pidTime: # continuous heating
       a.dialog('rout:close (@209)\n')
       a.dialog('rout:open (@206)\n')
       print 'heating 100%'
       time.sleep(timeLeft)
    elif heat < (-halfTime): #mostly cooling
       a.dialog('rout:open (@206,209)\n')
       print 'cooling %i' % (abs(heat) / pidTime * 100)
       time.sleep(invHeat)
       a.dialog('rout:close (@206)\n')
       snooze = timeLeft -invHeat
       if snooze < 0: snooze = 0 
       time.sleep(snooze)           
    elif heat > (halfTime): #mostly warming
       a.dialog('rout:open (@206,209)\n')
       print 'heating %i' % (heat / pidTime * 100)
       time.sleep(invHeat)
       a.dialog('rout:close (@209)\n')
       snooze = timeLeft -invHeat
       if snooze < 0: snooze = 0 
       time.sleep(snooze)           
    elif heat < 0: #a little cooling
       a.dialog('rout:close (@206)\n')
       a.dialog('rout:open (@209)\n')
       print 'cooling %i' % (abs(heat) / pidTime * 100)
       time.sleep(abs(heat))
       a.dialog('rout:open (@206)\n')
       snooze = timeLeft - abs(heat)
       if snooze < 0: snooze = 0 
       time.sleep(snooze)           
    elif heat > 0: # a little heating
       a.dialog('rout:close (@209)\n')
       a.dialog('rout:open (@206)\n')
       print 'heating %i' % (heat / pidTime * 100)
       time.sleep(heat)
       a.dialog('rout:open (@209)\n')
       snooze = timeLeft - heat
       if snooze < 0: snooze = 0 
       time.sleep(snooze)           
  except: # on any un-caught exception
    print 'Unexpected error. Closing down'
    vToB(-0.5, a)# sets Peltier to low volts
    break
  # end of while loop
#close safely
vToB(-0.5, a)# sets Peltier to low volts  
a.dialog('rout:open (@206:220)\n')
# end of program