Counting Two Pulses Generated By Rotating Motor

Question

I want to Count pulses based on some Conditions which are:

(1) Count all the rotations generated during motor Rotations.

(2) Count all the motor rotation pulses when an additional signal is enabled.

Code i am trying

import time
import pigpio
import RPi.GPIO as GPIO

pi = pigpio.pi()
good_count=0
rotationPin=4
GoodSignal=12

GPIO.setmode(GPIO.BOARD)
pi.set_mode(rotationPin, pigpio.INPUT)
GPIO.setup(GoodSignal, GPIO.IN, pull_up_down=GPIO.PUD_UP) 
pi.set_pull_up_down(rotationPin, pigpio.PUD_UP)

wind_cb = pi.callback(rotationPin, pigpio.FALLING_EDGE)
if(pi.read(rotationPin)==0 and GPIO.input(GoodSignal)==0):
    print ("Here is good Signal count")
    good_count+=1

old_count = 0

while True:
   time.sleep(5)
   count = wind_cb.tally() 
   print("counted {} pulses".format(count - old_count))
   old_count = count

pigpio.stop()

I am using pigpio library for counting pulses which gives correct count for all pulses but not able to achieve second condition.

Any help please

Edit: After Studying about pigpio library, i modify my code to this

import time
import pigpio
import RPi.GPIO as GPIO

pi = pigpio.pi()
good_count=0
rotationPin=4
GoodSignal=12

GPIO.setmode(GPIO.BOARD)
pi.set_mode(rotationPin, pigpio.INPUT)
GPIO.setup(GoodSignal, GPIO.IN, pull_up_down=GPIO.PUD_UP) 
pi.set_pull_up_down(rotationPin, pigpio.PUD_UP)
totalcount=0
def abc(gpio,level,tick):
    global totalcount,good_count
    totalcount +=1
    print("ABC")
    if(GPIO.input(GoodSignal)==GPIO.LOW):
       good_count +=1
wind_cb = pi.callback(rotationPin, pigpio.FALLING_EDGE, abc)


old_count = 0

while True:
   time.sleep(5)
   count = wind_cb.tally() 
   print("counted {} pulses".format(count - old_count))
   print("The total Count is "+str(totalcount))
   print("The Good Count is "+str(good_count))
   old_count = count

pi.stop()

The above code gives no error but i guess it is not efficient, Any Suggestion would be appreciated.

Answer 1

I'd use something like the following.

When you want to look at a GPIO in step with another GPIO use the same callback for both. That way you know the level of each GPIO at the same time. Trying to read() a GPIO in a callback is almost always the wrong thing to do. The thing which triggered the callback may have happened several milliseconds before.

#!/usr/bin/env python

import time
import pigpio

pi = pigpio.pi()
if not pi.connected:
   exit()


rotationPin=4
GoodSignal=12

GoodSignalLevel=pi.read(GoodSignal)

pi.set_pull_up_down(rotationPin, pigpio.PUD_UP)
pi.set_mode(rotationPin, pigpio.INPUT)

pi.set_pull_up_down(GoodSignal, pigpio.PUD_UP)
pi.set_mode(GoodSignal, pigpio.INPUT)

good_count=0
totalcount=0

def abc(gpio,level,tick):
    global totalcount,good_count,GoodSignalLevel
    if gpio == GoodSignal:
       GoodSignalLevel = level
    if gpio == rotationPin:
       totalcount +=1
       if GoodSignalLevel == pigpio.LOW:
          good_count += 1

wind_cb = pi.callback(rotationPin, pigpio.FALLING_EDGE, abc)
good_cb = pi.callback(GoodSignal, pigpio.EITHER_EDGE, abc)

old_count = 0

while True:
   time.sleep(5)
   count = totalcount
   print("counted {} pulses".format(count - old_count))
   print("The total Count is "+str(totalcount))
   print("The Good Count is "+str(good_count))
   old_count = count

wind_cb.cancel()
good_cb.cancel()

pi.stop()