heatpump.py

   1 import piplates.DAQCplate as DAQC
   2 import time
   3 from decimal import Decimal
   4 DAQC.setDOUTbit(0,0)
   5 #thermistor reading function
   6 def compressor(state=None):
   7     if state==None:
   8         return DAQC.getDOUTbyte(0)
   9     if state==True:
  10         DAQC.setDOUTbit(0,0)
  11     if state==False:
  12         DAQC.clrDOUTbit(0,0)
  13
  14 def temp_get(volts,supply_voltage=5):
  15     divider_resistor=10000
  16     ohms = Decimal(divider_resistor*supply_voltage/volts-divider_resistor) #calculate the ohms of the thermisttor
  17     #IVT oem NTC
  18     a = Decimal(1.298022762e-3)
  19     b = Decimal(2.365068126e-4)
  20     c = Decimal(0.9305914923e-7)
  21     #Steinhart Hart Equation
  22     # T = 1/(a + b[ln(ohm)] + c[ln(ohm)]^3)
  23     temp = 1/(a + b*ohms.ln() + c*ohms.ln()**3)
  24     tempc = temp - Decimal(273.15) #K to C
  25     return tempc
  26
  27 while(True):
  28     vv_retur=temp_get(DAQC.getADC(0,0),DAQC.getADC(0,8))
  29     vv_top=temp_get(DAQC.getADC(0,2),DAQC.getADC(0,8))
  30     hetgas=temp_get(DAQC.getADC(0,1),DAQC.getADC(0,8))
  31     print("VV retur:",vv_retur)
  32     print("VV top:",vv_top)
  33     print("Hetgas:",hetgas)
  34     print("Kompressor:",compressor())
  35     if vv_retur < 35:
  36         compressor(True)
  37         print("Returtemp under 35. Startar kompressor")
  38     if vv_retur > 45:
  39         compressor(False)
  40         print("Returtemp över 45. Stänger av kompressor")
  41 #    import pdb;pdb.set_trace()
  42     time.sleep(1)
  43