#2 May 2025
"""
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/ Laptop Cloud IOT
1. Install Mosquitto
2. Install Node Red
3. Install Node Red Dashboard

Now click on the HC-SR04 sensor in the simulation,
change the distance, and you should see
the message appear on the MQTT Broker, in the "Messages" pane.

Copyright (C) 2025, M Kamarul Zaman

https://wokwi.com/projects/429166796278789121
"""

import network
import ujson
import time
from machine import Pin, SoftI2C
from neopixel import NeoPixel
from umqtt.simple import MQTTClient
from hcsr04 import HCSR04
import ssd1306

# --- Hardware Setup ---
pixels = NeoPixel(Pin(4), 16)
pixels.fill((0, 0, 0))
pixels.write()

sensor = HCSR04(trigger_pin=5, echo_pin=18, echo_timeout_us=100000)

i2c = SoftI2C(scl=Pin(22), sda=Pin(21))
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# --- WiFi Connection ---
print("Connecting to WiFi...", end="")
wifi = network.WLAN(network.STA_IF)
wifi.active(True)
wifi.connect("Wokwi-GUEST", "")
while not wifi.isconnected():
    print(".", end="")
    time.sleep(0.5)
print(" Connected!")

# --- MQTT Configuration ---
MQTT_CLIENT_ID = ""
MQTT_BROKER = "test.mosquitto.org"
MQTT_USER = ""
MQTT_PASSWORD = ""
MQTT_TOPIC_PUB = "huda/distance"
MQTT_TOPIC_SUB = "huda/rgb"

# --- RGB Override Flag ---
rgb_override = False

# --- MQTT Callback ---
def mqtt_message(topic, msg):
    global rgb_override
    print("Incoming message:", msg)
    try:
        data = ujson.loads(msg)
        if isinstance(data, list) and len(data) == 3:
            r, g, b = [int(x) for x in data]
            pixels.fill((r, g, b))
            pixels.write()
            rgb_override = True

            oled.fill(0)
            oled.text("RGB Value", 0, 0)
            oled.text("R: {}".format(r), 0, 20)
            oled.text("G: {}".format(g), 0, 35)
            oled.text("B: {}".format(b), 0, 50)
            oled.show()
        else:
            print("Invalid RGB format")
    except Exception as e:
        print("Error in MQTT callback:", e)

# --- Connect to MQTT ---
print("Connecting to MQTT...", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.set_callback(mqtt_message)
client.connect()
client.subscribe(MQTT_TOPIC_SUB)
print(" Connected!")

# --- Main Loop ---
prev_distance = ""

while True:
    try:
        distance = sensor.distance_cm()
        print("Distance:", distance, "cm")
        message = ujson.dumps(distance)

        if message != prev_distance:
            client.publish(MQTT_TOPIC_PUB, message)
            prev_distance = message
            print("Published:", message)

            if not rgb_override:
                if distance > 300:
                    pixels.fill((255, 0, 0))  # Red
                else:
                    pixels.fill((0, 255, 0))  # Green
                pixels.write()
        else:
            print("No distance change.")

        client.check_msg()
        rgb_override = False  # Reset after each loop

    except Exception as e:
        print("Main loop error:", e)

    time.sleep(1)