reading pulse count using raspberry pi in python [closed]

Question

I have been trying to read the number of pulse inputs from an external device. The pulse generated is from the arduino uno, and the pin I am using has a frequency of 450hz with 5% duty cycle.

Every time the pulse count shows aroung 2300-3000 per second.

I also have check the frequency of the arduino pin using an Oscilloscope

model- raspberry pi zero W

below is my python code for counting pulse using interrupts to count the pulse within a time interval of 1 sec.

import RPi.GPIO as GPIO
import time, sys

pulse_gpio=26

GPIO.setmode(GPIO.BCM)
GPIO.setup(pulse_gpio,GPIO.IN, pull_up_down=GPIO.PUD_UP)

global count
count=0

def counting(channel):
        global count
        if start_counter==1:
                count=count+1

GPIO.add_event_detect(pulse_gpio, GPIO.FALLING, callback=counting)

while True:
        try:
                start_counter=1
                time.sleep(1)
                start_counter=0
                flow=count
                print(flow)
                count=0
                #time.sleep(0.5)
        except keyboardInterrupt:
                print("keyboard")
                GPIO.cleanup()
                sys.exit()

Answer 1

pigpio is likely to be more accurate for this task.

With the pigpio daemon running (sudo pigpiod) run the following Python code.

import time
import pigpio

COUNT_GPIO=20

pi = pigpio.pi()

if not pi.connected:
   exit()

cb = pi.callback(COUNT_GPIO)

while True:

   time.sleep(1)
   print(cb.tally())
   cb.reset_tally()

cb.cancel()
pi.stop()

Ref http://abyz.me.uk/rpi/pigpio/python.html#callback