flowMQTT.py

# flow meter wiring
# power -> 3v3 Pin38
# ground -> ground Pin36
# signal -> GPIO15 Pin20

import machine
from machine import Pin, I2C
import utime
import network
import time
import ujson
from umqtt.simple import MQTTClient

# Configure network connection
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
wlan.connect(SSID, PASSWORD)
time.sleep(5)
print("WLAN Conection Status: ", wlan.isconnected())

# Configure MQTT
mqtt_server = SERVER_IP
client_id = 'water_meter'
topic_pub = b'water/update'

# Set water_value for global use
water_value = 0.0

# Configure GPIO pins
flow_pin = machine.Pin(15, machine.Pin.IN)

# Configure water flow variables
flow_frequency = 0
gallons_p_minute = 0.0
total_gallons = 0.0
start_time = utime.ticks_ms()
FLOW_CALIB = 37.64

# Define interrupt function to calculate flow frequency
def handle_interrupt(pin):
    global flow_frequency
    flow_frequency += 1

# Configure interrupt on falling edge of flow sensor signal
flow_pin.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_interrupt)


# Connect to MQTT client
def mqtt_connect():
    client = MQTTClient(client_id, mqtt_server, keepalive=3600)
    client.connect()
    print('Connected to %s MQTT Broker'%(mqtt_server))
    client.publish("connect/water", '{"client_id": "water_meter" , "status": "connected"}')
    return client

def reconnect():
    print('Failed to connect to the MQTT Broker. Reconnecting...')
    time.sleep(5)
    machine.reset()

try:
    client = mqtt_connect()
except OSError as e:
    reconnect()



# Main loop to calculate and print water flow

while True:
    # Calculate liters per minute based on flow frequency
    gallons_p_minute = flow_frequency / FLOW_CALIB

    # Calculate total liters based on liters per minute and elapsed time
    current_time = utime.ticks_ms()
    elapsed_time = utime.ticks_diff(current_time, start_time) / 1000
    total_gallons += (gallons_p_minute / 60) * elapsed_time

    # Print total gallons and reset count
    print("New water flow: {:.2f} gallons".format(total_gallons))
    if flow_frequency > 0:
        print("new conspumption", total_gallons)
        data = {"consumption": total_gallons}
        msg = ujson.dumps(data).encode()
        client.publish(topic_pub, msg)
        total_gallons = 0
    flow_frequency = 0

    # Delay for 10 second
    utime.sleep(10)