#!/usr/bin/python3
#coding: utf-8

from smbus2 import SMBus
import time

bus_number  = 1

bus = SMBus(bus_number)

digT = []
digP = []

temperature = 0.0
pressure = 0.0

def writeReg(i2c_addr, reg_address, data):
	bus.write_byte_data(i2c_addr, reg_address, data)
	time.sleep(0.01)

def setup(i2c_address):
	osrs_t = 1			#Temperature oversampling x 1
	osrs_p = 1			#Pressure oversampling x 1
#	osrs_h = 1			#Humidity oversampling x 1
	osrs_h = 0			#Humidity oversampling x 1
#	mode   = 3			#Normal mode
	mode   = 1			#Forced mode
#	t_sb   = 5			#Tstandby 1000ms
	t_sb   = 0			#Tstandby 0ms
	filter = 0			#Filter off
	spi3w_en = 0		#3-wire SPI Disable

	ctrl_meas_reg = (osrs_t << 5) | (osrs_p << 2) | mode
	config_reg    = (t_sb << 5) | (filter << 2) | spi3w_en
	ctrl_hum_reg  = osrs_h

	writeReg(i2c_address, 0xF2, ctrl_hum_reg)
	writeReg(i2c_address, 0xF4, ctrl_meas_reg)
	writeReg(i2c_address, 0xF5, config_reg)
	calib = []
	for i in range (0x88, 0x88+24):
		calib.append(bus.read_byte_data(i2c_address, i))
#	calib.append(bus.read_byte_data(i2c_address,0xA1))
#	for i in range (0xE1, 0xE1+7):
#		calib.append(bus.read_byte_data(i2c_address, i))

	digT.clear()
	digP.clear()
	digT.append((calib[1] << 8) | calib[0])
	digT.append((calib[3] << 8) | calib[2])
	digT.append((calib[5] << 8) | calib[4])
	digP.append((calib[7] << 8) | calib[6])
	digP.append((calib[9] << 8) | calib[8])
	digP.append((calib[11]<< 8) | calib[10])
	digP.append((calib[13]<< 8) | calib[12])
	digP.append((calib[15]<< 8) | calib[14])
	digP.append((calib[17]<< 8) | calib[16])
	digP.append((calib[19]<< 8) | calib[18])
	digP.append((calib[21]<< 8) | calib[20])
	digP.append((calib[23]<< 8) | calib[22])
	
	for i in range(1, 2):
		if digT[i] & 0x8000:
			digT[i] = (-digT[i] ^ 0xFFFF) + 1

	for i in range(1, 8):
		if digP[i] & 0x8000:
			digP[i] = (-digP[i] ^ 0xFFFF) + 1

def measure(i2c_address):
	setup(i2c_address)
	data = []
	global temperature
	global pressure
	for i in range (0xF7, 0xF7+6):
		data.append(bus.read_byte_data(i2c_address, i))
	pres_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4) & 0xf
	temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4) & 0xf

	var1 = ((((temp_raw>>3) - (digT[0]<<1))) * (digT[1])) >> 11
	var2 = (((((temp_raw>>4) - (digT[0])) * ((temp_raw>>4) - (digT[0]))) >> 12) * (digT[2])) >> 14
	t_fine = var1 + var2 - 25574	#5C:=25574.4
	T = (t_fine * 5 + 128) >> 8
	temperature = T / 100.0

	var1 = (t_fine) - 128000
	var2 = var1 * var1 * digP[5]
	var2 = var2 + ((var1*digP[4])<<17)
	var2 = var2 + ((digP[3])<<35)
	var1 = ((var1 * var1 * digP[2])>>8) + ((var1 * digP[1])<<12)
	var1 = ((((1)<<47)+var1))*digP[0]>>33
	if var1 == 0:
		return
	p = 1048576 - pres_raw
	p = (((p<<31) - var2)*3125) / var1
#	var1 = ((digP[8]) * (p>>13) * (p>>13)) >> 25
	var1 = ((digP[8]) * (p/8192) * (p/8192)) / 33554432
#	var2 = ((digP[7]) * p) >> 19
	var2 = ((digP[7]) * p) / 524288
	p = ((p + var1 + var2) / 256) + ((digP[6])<<4)
	pressure = p / 25600.0

def read_temp():
	t1 = 0
	t2 = 0
	try:
		measure(0x76)
		t1 = round(temperature, 1)
		measure(0x77)
		t2 = round(temperature, 1)
		return t1, t2
	except:
		return t1, t2

if __name__ == '__main__':
	try:
		measure(0x76)
		print("pressure1 : %7.2f hPa" % (pressure))
		print("temp1 : %-6.2f C" % (temperature)) 
		measure(0x77)
		print("pressure2 : %7.2f hPa" % (pressure))
		print("temp2 : %-6.2f C" % (temperature)) 
	except:
		pass