Need Assist in Programing Flowmeter and temperature sensor to the RaspberryPi (Python)

What is the problem with this second code ?

The indentation is lost when pasting code here, and unfortunately it's hard to follow unindented Python code.

I do apologize, I didn't realize that copy and paste messed with the indentation.

the problem is that only output i see to the screen is the 'error' instead of seeing the frequency. If i can get the frequency i should be able to make it work with that.

Perhaps you want 'and' rather than '&'.  The latter is doing a bitwise AND where I think you want a logical AND?

Regards,

Martyn

I think martyndavies hit the nail on the head.

try with :

  if( (gflowcount == 1) and (gpio.input(22) == True) ):

The same in the next if statement.

else if( (gflowcount == 2) and (gpio.input(22) == True) ):

In other languages - C, Java, ... - the logical AND is written "&&".

May be that's what caused that error.

I think martyndavies hit the nail on the head.

try with :

  if( (gflowcount == 1) and (gpio.input(22) == True) ):

The same in the next if statement.

else if( (gflowcount == 2) and (gpio.input(22) == True) ):

In other languages - C, Java, ... - the logical AND is written "&&".

May be that's what caused that error.

hey guys i just found out that there's a noise issue with the breadboard that i'm using so i'll need to address that first.

i'll keep in touch. thanks for all your help.

hey guys i'm back. I have fixed the noise issue and have completed most of the program but i need some help to do the final touches.

what i need to do is in the

def glycolFlow():

and in the

def waterFlow():

when those functions are called, inside the function it need to look to see if there is a pulse for 2 seconds. if the pulse is there then the rest of the function can execute if the pulse is not there within 2 seconds then the function returns 0.0 instead of the calculated data.

import os
import glob
import time
import RPi.GPIO as gpio

# Initializing GPIO ports
boardRevision = gpio.RPI_REVISION # Clearing previous gpio port settings
gpio.setmode(gpio.BCM) # Use real physical gpio port numbering
gpio.setup(18, gpio.IN, pull_up_down=gpio.PUD_UP) # setting pin 18 as pull up resistor for glycol flow meter
gpio.setup(25, gpio.IN, pull_up_down=gpio.PUD_UP) # setting pin 12 as pull up resistor for water flow meter


# starting thermal probe drivers
os.system('sudo modprobe w1-gpio')
os.system('sudo modprobe w1-therm')


# setting sensors data file location
sensor1_file = '/sys/bus/w1/devices/28-000004a8873d/w1_slave'
sensor2_file = '/sys/bus/w1/devices/28-00000574c16a/w1_slave'
sensor3_file = '/sys/bus/w1/devices/28-00000561223c/w1_slave'
sensor4_file = '/sys/bus/w1/devices/28-00000560107a/w1_slave'
sensor5_file = '/sys/bus/w1/devices/28-00000560dca6/w1_slave'
sensor6_file = '/sys/bus/w1/devices/28-0000057478b2/w1_slave'


def glycolFlow():
  glycolStartTime = int(time.time())
  print 'glycol start time', glycolStartTime
  glycolCount = 0
  while glycolCount < 15 :
       if gpio.input(18) == True:
            if gpio.input(18) == False:
                 glycolCount += 1
                 print 'glycol count', glycolCount
  glycolEndTime = int(time.time())
  print 'glycol end time', glycolEndTime
  glycolSecsPerLiters = glycolEndTime - glycolStartTime
  glycolLitersPerHour = (3600.0 / glycolSecsPerLiters) * 30
  glycolGalPerHour = glycolLitersPerHour * 0.26417205235815
  return glycolGalPerHour


def waterFlow():
  waterStartTime = int(time.time())
  print 'water start time', waterStartTime
  waterCount = 0
  print 'water count', waterCount
  while waterCount < 15 :
       if gpio.input(25) == True:
            if gpio.input(25) == False:
                 waterCount += 1
                 print 'water count', waterCount
  waterEndTime = int(time.time())
  print 'water end time', waterEndTime
  waterSecsPerLiters = waterEndTime - waterStartTime
  waterLitersPerHour = (3600.0 / waterSecsPerLiters) * 30
  waterGalPerHour = waterLitersPerHour * 0.26417205235815
  return waterGalPerHour


def ts1():
  s1 = open(sensor1_file, 'r')
  s1lines = s1.readlines()
  s1.close()
  while s1lines[0].strip()[-3:] !='YES':
       s1lines = sensor1_raw()
  equals_pos1 = s1lines[1].find('t=')
  if equals_pos1 != -1:
       temp_string1 = s1lines[1][equals_pos1+2:]
       temp_c1 = float(temp_string1) / 1000.0
       temp_f1 = temp_c1 * 9.0 / 5.0 + 32.0
  return temp_c1


def ts2():
  s2 = open(sensor2_file, 'r')
  s2lines = s2.readlines()
  s2.close()
  while s2lines[0].strip()[-3:] !='YES':
       s2lines = sensor2_raw()
  equals_pos2 = s2lines[1].find('t=')
  if equals_pos2 != -1:
       temp_string2 = s2lines[1][equals_pos2+2:]
       temp_c2 = float(temp_string2) / 1000.0
       temp_f2 = temp_c2 * 9.0 / 5.0 + 32.0
  return temp_c2


def ts3():
  s3 = open(sensor3_file, 'r')
  s3lines = s3.readlines()
  s3.close()
  while s3lines[0].strip()[-3:] !='YES':
       s3lines = sensor3_raw()
  equals_pos3 = s3lines[1].find('t=')
  if equals_pos3 != -1:
       temp_string3 = s3lines[1][equals_pos3+2:]
       temp_c3 = float(temp_string3) / 1000.0
       temp_f3 = temp_c3 * 9.0 / 5.0 + 32.0
  return temp_c3


def ts4():
  s4 = open(sensor4_file, 'r')
  s4lines = s4.readlines()
  s4.close()
  while s4lines[0].strip()[-3:] !='YES':
       s4lines = sensor4_raw()
  equals_pos4 = s4lines[1].find('t=')
  if equals_pos4 != -1:
       temp_string4 = s4lines[1][equals_pos4+2:]
       temp_c4 = float(temp_string4) / 1000.0
       temp_f4 = temp_c4 * 9.0 / 5.0 + 32.0
  return temp_c4


def ts5():
  s5 = open(sensor5_file, 'r')
  s5lines = s5.readlines()
  s5.close()
  while s5lines[0].strip()[-3:] !='YES':
       s5lines = sensor5_raw()
  equals_pos5 = s5lines[1].find('t=')
  if equals_pos5 != -1:
       temp_string5 = s5lines[1][equals_pos5+2:]
       temp_c5 = float(temp_string5) / 1000.0
       temp_f5 = temp_c5 * 9.0 / 5.0 + 32.0
  return temp_c5


def ts6():
  s6 = open(sensor6_file, 'r')
  s6lines = s6.readlines()
  s6.close()
  while s6lines[0].strip()[-3:] !='YES':
       s6lines = sensor6_raw()
  equals_pos6 = s6lines[1].find('t=')
  if equals_pos6 != -1:
       temp_string6 = s6lines[1][equals_pos6+2:]
       temp_c6 = float(temp_string6) / 1000.0
       temp_f6 = temp_c6 * 9.0 / 5.0 + 32.0
  return temp_c6


while True:
  glycolGalPerHour = glycolFlow()
 if glycolGalPerHour != 0.0:
       ts1 = ts1()
       ts2 = ts2()
       ts3 = ts3()
       ts4 = ts4()
 else:
       ts1 = 0
       ts2 = 0
       ts3 = 0
       ts4 = 0
  waterGalPerHour = waterFlow()
 if waterGalPerHour != 0.0:
       ts6 = ts6()
       ts5 = ts5()
 else:
       ts5 = 0
       ts6 = 0
  ts5 = ts5()
  ts6 = ts6()
  print "Glycol flow =", glycolGalPerHour, "Gal/Hour"
  print('sensor1', ts1)
  print('sensor2', ts2)
  print('sensor3', ts3)
  print('sensor3', ts4)
  print "water flow =", waterGalPerHour, "Gal/Hour"
  print('sensor5', ts5)
  print('sensor6', ts6)
  print '---------------------------------'
  time.sleep(30)

Hi Priyam,

Can I get your advice on programming a hall-effect flow meter with the Raspberry Pi?

Ultimately I would like to log the water flow data over time and then calculate the total volume of each continuous stream (ie. if flow drops to 0 for x seconds then start a new total).

As a start, I want to make sure that I can replicate your implementation. Will this (below) do the job?

    import os  
    import glob  
    import time  
    import RPi.GPIO as gpio  
      
    # Initializing GPIO ports  
    boardRevision = gpio.RPI_REVISION # Clearing previous gpio port settings  
    gpio.setmode(gpio.BCM) # Use real physical gpio port numbering  
     gpio.setup(25, gpio.IN, pull_up_down=gpio.PUD_UP) # setting pin 12 as pull up resistor for water flow meter  
      
      
    def waterFlow():  
      waterStartTime = int(time.time())  
      print 'water start time', waterStartTime  
      waterCount = 0  
      print 'water count', waterCount  
      while waterCount < 15 :  
           if gpio.input(25) == True:  
                if gpio.input(25) == False:  
                     waterCount += 1  
                     print 'water count', waterCount  
      waterEndTime = int(time.time())  
      print 'water end time', waterEndTime  
      waterSecsPerLiters = waterEndTime - waterStartTime  
      waterLitersPerHour = (3600.0 / waterSecsPerLiters) * 30   
      return waterLitersPerHour  
      
      print "water flow =", waterLitersPerHour, "l/Hour"  

      print '---------------------------------'  
      time.sleep(30) 

no that was just another test program not working properly.

the program below is the that i'm using at the moment.

it first checks to see if there is a flow or not. if there is no flow then it returns zero. if there flow then it returns the instantaneous flow rate by looking at the pulses that the flow meter is putting out but if the flow stops before there is enough data to be able to calculate the flow then it will return zero. from there you can take those data points and plot them on excel and figure out the area under the curve to get your total flow from starting to stop and for how long it stopped also.

import os # importing OS module just in-case needed 
import time # Importing Time module
import RPi.GPIO as gpio # Importing RPIO module as gpio


# Initializing GPIO ports
boardRevision = gpio.RPI_REVISION # Clearing previous gpio port settings
gpio.setmode(gpio.BCM) # Use real physical gpio port numbering
gpio.setup(25, gpio.IN, pull_up_down=gpio.PUD_UP) # setting pin 22 as pull up resistor


def glycolFlow():
  glycolCurrentTime = int(time.time())
  glycolErrorStopTime = glycolCurrentTime + 1
  glycolTimingPulse = 0
  while glycolCurrentTime <= glycolErrorStopTime:
       if gpio.input(25) == True:
            if gpio.input(25) == False:
                 glycolTimingPulse += 1
            else:
                 glycolCurrentTime = int(time.time())
       else:
            glycolCurrentTime = int(time.time())

  if glycolTimingPulse != 0:
       glycolStartTime = int(time.time())
       print 'glycol start time', glycolStartTime
       waitTimerglycol = glycolStartTime + 2
       waitTimerCountglycol = int(time.time())
       glycolCount = 0
       print 'glycol count', glycolCount
       while (glycolCount < 15) and (waitTimerCountglycol <= waitTimerglycol) :
            if gpio.input(25) == True:
                 if gpio.input(25) == False:
                      glycolCount += 1
                      print 'glycol count', glycolCount
                      waitTimerglycol = int(time.time()) + 1
                 else:
                      waitTimerCountglycol = int(time.time())
            else:
                 waitTimerCountglycol = int(time.time())
      glycolEndTime = int(time.time())
       print 'glycol end time', glycolEndTime
       if glycolCount == 15:
            glycolSecsPerLiters = glycolEndTime - glycolStartTime
            glycolLitersPerHour = (3600.0 / glycolSecsPerLiters) * 30
            glycolGalPerHour = glycolLitersPerHour * 0.26417205235815
            return glycolGalPerHour
       else:
            glycolGalPerHour = 0
       return glycolGalPerHour
  else:
       glycolGalPerHour = 0
       return glycolGalPerHour

while True:
  glycolGalPerHour = glycolFlow()
  print "glycol flow =", glycolGalPerHour, "Gal/Hour"

Great, I'll look forward to testing.

It's a bit worrying for accuracy when you say that:

if the flow stops before it can calculate flow then it will return zero

Is this a question of processing speed? If so then (from what I've read) C++ may be more suitable.

well what is happening is that i'm actually using two different flow meters at the same time so i'm altering between the two to get the instantaneous speed of them because that's what i need to do the calculations that i require. but if you need to do something else then you can modify the program to do what you wish.

as long as you rate of flow is somewhere within the capacity of the flow meter that you are using then you should not have any issue.