import time
from machine import Pin, I2C

# BMP180 constants
BMP180_ADDR = 0x77  # Default I2C address for BMP180 sensor
CONTROL_REG = 0xF4
RESULT_REG = 0xF6

# BMP180 Commands
TEMPERATURE_CMD = 0x2E
PRESSURE_CMD = 0x34

class BMP180:
    def __init__(self, i2c):
        self.i2c = i2c
        self.addr = BMP180_ADDR

        # Read calibration data from the sensor
        self.ac1 = self._read_signed_int16(0xAA)
        self.ac2 = self._read_signed_int16(0xAC)
        self.ac3 = self._read_signed_int16(0xAE)
        self.ac4 = self._read_unsigned_int16(0xB0)
        self.ac5 = self._read_unsigned_int16(0xB2)
        self.ac6 = self._read_unsigned_int16(0xB4)
        self.b1 = self._read_signed_int16(0xB6)
        self.b2 = self._read_signed_int16(0xB8)
        self.mb = self._read_signed_int16(0xBA)
        self.mc = self._read_signed_int16(0xBC)
        self.md = self._read_signed_int16(0xBE)

    def _read_signed_int16(self, reg):
        data = self.i2c.readfrom_mem(self.addr, reg, 2)
        return (data[0] << 8) + data[1] if data[0] >= 0x80 else (data[0] << 8) + data[1]

    def _read_unsigned_int16(self, reg):
        data = self.i2c.readfrom_mem(self.addr, reg, 2)
        return (data[0] << 8) + data[1]

    def _write(self, reg, value):
        self.i2c.writeto_mem(self.addr, reg, bytearray([value]))

    def _read_temperature(self):
        self._write(CONTROL_REG, TEMPERATURE_CMD)
        time.sleep(0.005)  # Wait for conversion
        msb, lsb = self.i2c.readfrom_mem(self.addr, RESULT_REG, 2)
        ut = (msb << 8) + lsb
        x1 = ((ut - self.ac6) * self.ac5) >> 15
        x2 = (self.mc << 11) // (x1 + self.md)
        b5 = x1 + x2
        temperature = (b5 + 8) >> 4
        return temperature

    def _read_pressure(self):
        self._write(CONTROL_REG, PRESSURE_CMD)
        time.sleep(0.026)  # Wait for conversion
        msb, lsb, xlsb = self.i2c.readfrom_mem(self.addr, RESULT_REG, 3)
        up = (msb << 16) + (lsb << 8) + xlsb
        up >>= 8  # Adjust for MSB
        return up

    def get_temperature(self):
        temperature = self._read_temperature()
        return temperature / 10.0  # Convert to Celsius

    def get_pressure(self):
        pressure = self._read_pressure()
        return pressure  # Return pressure in Pa

    def get_altitude(self, pressure):
        # Assume sea-level pressure of 1013.25 hPa
        return 44330 * (1 - (pressure / 101325) ** 0.1903)

# Set up I2C
i2c = I2C(0, scl=Pin(22), sda=Pin(21))  # Adjust the pins for your ESP32 setup

# Initialize BMP180 sensor
bmp = BMP180(i2c)

# Main loop
while True:
    # Read temperature and pressure
    temp = bmp.get_temperature()
    pressure = bmp.get_pressure()
    altitude = bmp.get_altitude(pressure)

    # Print results
    print("Temperature: {:.2f} C".format(temp))
    print("Pressure: {:.2f} Pa".format(pressure))
    print("Altitude: {:.2f} meters".format(altitude))

    time.sleep(2)  # Wait 2 seconds before the next reading