rctimer.py

#!/usr/bin/python
import RPi.GPIO as gpio
import time
import math
gpio.setmode(gpio.BOARD)
gpio.setwarnings(False)
print('Temperature oC')
print('-------------------')
while True:
  gpio.setup (5, gpio.IN)
  gpio.setup (3, gpio.OUT)
  gpio.output(3, gpio.LOW)
  time.sleep(0.08)
  gpio.setup(3, gpio.IN)
  starttime=time.time()
  endtime=starttime
  try:
    while gpio.input(5) == gpio.LOW:
      endtime = time.time()
      if endtime-starttime >5:
        raise Exception('We waited too long for the pin to turn high, did not receive the signal')
    time_factor = (endtime-starttime)/0.00315
    e=2.71828
    up_voltage=1.32
    opamp_gain=4.8
    supply=up_voltage /(opamp_gain* (1-(math.pow(e,-time_factor))))
    print(supply*100)
  except Exception as e:
    print(str(e))
    continue
  finally:
    time.sleep(5)