from machine import Pin, I2C, ADC
import onewire, ds18x20, time
from ssd1306 import SSD1306_I2C

# I2C setup for OLED
i2c = I2C(0, scl=Pin(1), sda=Pin(0), freq=400000)
oled = SSD1306_I2C(128, 64, i2c)

# MQ135 on ADC0 (GP26)
mq135 = ADC(Pin(26))

# DS18B20 setup
dat = Pin(2)
ds_sensor = ds18x20.DS18X20(onewire.OneWire(dat))

roms = ds_sensor.scan()
if not roms:
    oled.fill(0)
    oled.text("No DS18B20", 0, 0)
    oled.show()
    raise Exception("No DS18B20 sensor found!")
else:
    print('Found DS18B20:', roms)

while True:
    # Read MQ135 gas value
    gas_value = mq135.read_u16()

    # Read temperature
    ds_sensor.convert_temp()
    time.sleep_ms(750)
    temp_c = ds_sensor.read_temp(roms[0])

    # Display on OLED
    oled.fill(0)
    oled.text("Env Monitor", 0, 0)
    oled.text("Gas: {}".format(gas_value), 0, 16)
    oled.text("Temp: {:.1f}C".format(temp_c), 0, 32)
    oled.show()

    time.sleep(1)