from machine import Pin
from mq2 import MQ2
from picozero import Speaker
from time import sleep, ticks_ms, ticks_diff
import urequests
import network

ssid = "Wokwi-GUEST"
password = ""
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
wlan.connect(ssid, password)

while not wlan.isconnected():
    print("Connecting")
    pass

if wlan.isconnected():
	print("Connected")

write_api_key = "9T55Y4V145AES9H7"
url = "https://api.thingspeak.com/update"

# Link to ThingSpeak dashboard
# https://thingspeak.mathworks.com/channels/3258549

last_send = 0

threshold = 30 # Threshold for methane leakage

mq2Pin = 26
redPin = Pin(12, Pin.OUT)
greenPin = Pin(11, Pin.OUT)
bluePin = Pin(10, Pin.OUT)

sensor = MQ2(pinData = mq2Pin, baseVoltage = 3.3)
speaker = Speaker(9)

redPin.value(0)
greenPin.value(0)
bluePin.value(0)

speaker.off()

print("Calibrating")
sensor.calibrate()
print("Calibration completed")
print("Base resistance:{0}".format(sensor._ro))

while True:
	if last_send is 0:
		last_send = ticks_ms()

	methaneConc = sensor.readMethane()

	# Send req to thingspeak every 16 sec 
	if ticks_diff(ticks_ms(), last_send) > 16000:
		try:
			response = urequests.get(f"{url}?api_key={write_api_key}&field1={methaneConc}")
			if response.status_code == 200:
				print("Data sent to ThingSpeak!!!")
		except Exception as e:
			print(f"Error: {e}")
		finally:	
			response.close()
			last_send = 0
			pass

	if methaneConc > threshold:
		redPin.value(1)
		greenPin.value(0)
		bluePin.value(0)
		speaker.on();
	else:
		redPin.value(0)
		greenPin.value(1)
		bluePin.value(0)
		speaker.off()

	print(f"Methane Concentration: {methaneConc:.2f}")
	sleep(0.5)