#20 November 2023
"""
MicroPython IoT using ESP32 +HC-SR04

To view the data:
A: Mosquitto.Org 
1. Ultrasonic Distance. Go to terminal : mosquitto_sub -h test.mosquitto.org -t mkz/distance
2. Download IoT MQTT Panel for your android phone
3. Plot gauge and graph for Temperature and Humidity

B: Raspberry Pi 3 Cloud IOT
1. Install Mosquitto
2. Install Node Red
3. Install Node Red Dashboard

Now click on the DHT22 sensor in the simulation,
change the temperature/humidity, and you should see
the message appear on the MQTT Broker, in the "Messages" pane.

Copyright (C) 2022, M Kamarul Zaman

https://wokwi.com/projects/360421664389825537
"""

import network
import time
from machine import Pin
import dht
import ujson
from umqtt.simple import MQTTClient

from hcsr04 import HCSR04
from time import sleep

# MQTT Server Parameters
MQTT_CLIENT_ID = "clientId-pTYBHPQTD9"
MQTT_BROKER    = "mqtt-dashboard.com"
MQTT_USER      = "amirsaahal"
MQTT_PASSWORD  = "Fihifzillah1@"
MQTT_TOPIC     = "AMIRSAAHAL/Distance" # change to your topic

# ESP32
#sensor1 = HCSR04(trigger_pin=5, echo_pin=18, echo_timeout_us=100000)
sensor1 = HCSR04(trigger_pin=5, echo_pin=18, echo_timeout_us=100000)

print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('Wokwi-GUEST', '')
while not sta_if.isconnected():
  print(".", end="")
  time.sleep(0.1)
print(" Connected!")

print("Connecting to MQTT server... ", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.connect()

print("Connected!")

prev_distance = ""
while True:
  distance = sensor1.distance_cm()
  print('Distance:', distance, 'cm')
  sleep(1)

  message = ujson.dumps(distance)
  if message != prev_distance:
    print("Updated!")
    print("Reporting to MQTT topic {}:{} ".format(MQTT_TOPIC, message))
    client.publish(MQTT_TOPIC, message)
    prev_distance = message
  
  else:
    print("No change")
  time.sleep(1)