SequentMicrosystems_API/scripts/speed_reader.py

from src.variables.service import get_variable, set_variable
from gpiozero import Button
import datetime, os, json

pulses_per_rotation = 4
reader = Button(4, pull_up=False, bounce_time=0.0005)
set_variable("speed_reader_last_impulse_time", datetime.datetime.now(), False)
#set_variable("actual_rpm_unfiltered", 0, False)
set_variable("rpm_filter", json.dumps([0]), False)

if get_variable("rpm_filter_count") == None:
    set_variable("rpm_filter_count", 8, True)

def printer(text):
    if bool(os.getenv("DEBUG")):
        print(text)

def event():
    actual = datetime.datetime.now()
    last = get_variable("speed_reader_last_impulse_time")
    difference = (actual - last).total_seconds()
    set_variable("speed_reader_last_impulse_time", actual, False)

    rpm = (60 / difference) / pulses_per_rotation
    
    #actual_rpm = (float(get_variable("actual_rpm_unfiltered")) + rpm) / 2
    #set_variable("actual_rpm_unfiltered", rpm, False)

    rpm_filter = json.loads(get_variable("rpm_filter"))
    print(rpm_filter)

    while len(rpm_filter) > int(get_variable("rpm_filter_count")):
        rpm_filter.remove(rpm_filter[0])
    
    rpm_filter.append(rpm)
    set_variable("rpm_filter", json.dumps(rpm_filter), False)

    average = 0
    for i in rpm_filter:
        average = average + i
    
    actual_rpm = average / len(rpm_filter)

    set_variable("actual_rpm", round(actual_rpm, 1), False)
    printer("Measured RPM: {}".format(round(actual_rpm, 1)))
    
    



reader.when_pressed = event