Update: 30.07.2017 – as of now – latest stable domoticz version supports BME280, so this is now obsolete! The Hardware menu has now I2C Sensors and BME280 is present in submenu]
This is a modification of: https://bitbucket.org/MattHawkinsUK/rpispy-misc/raw/master/python/bme280.py, which after you change the IP address and port of Domoticz in ip_domoticz, and creating dummy sensor in Domoticz – “Temp+Humi+Baro” – and then changing the IDX to it’s value in: idx_dummy_bme280 – will update the sensor with the same data as you can see while running the program. This program will update Domoticz via JSON.
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Modified bme280.py:
#!/usr/bin/python
#--------------------------------------
# ___ ___ _ ____
# / _ \/ _ \(_) __/__ __ __
# / , _/ ___/ /\ \/ _ \/ // /
# /_/|_/_/ /_/___/ .__/\_, /
# /_/ /___/
#
# bme280.py
# Read data from a digital pressure sensor.
#
# Official datasheet available from :
# https://www.bosch-sensortec.com/bst/products/all_products/bme280
#
# Author : Matt Hawkins
# Date : 25/07/2016
#
# Modiification to allow updating dummy sensor in domoticz by: Lukasz Jokiel, 26/03/2017
#
# http://www.raspberrypi-spy.co.uk/
#
#--------------------------------------
import smbus
import time
import urllib2
import json
from ctypes import c_short
from ctypes import c_byte
from ctypes import c_ubyte
# The IP address of domoticz and IDX of the dummy Temp+Humi+Baro sensor - check in Devices section and change
ip_domoticz = "127.0.0.1:8080"
idx_dummy_bme280 ="1"
DEVICE = 0x76 # Default device I2C address
def update_bm280_sensor_in_domoticz (url):
request = urllib2.Request(url)
response = urllib2.urlopen(request)
return response.read()
bus = smbus.SMBus(1) # Rev 2 Pi, Pi 2 & Pi 3 uses bus 1
# Rev 1 Pi uses bus 0
def getShort(data, index):
# return two bytes from data as a signed 16-bit value
return c_short((data[index+1] << 8) + data[index]).value
def getUShort(data, index):
# return two bytes from data as an unsigned 16-bit value
return (data[index+1] << 8) + data[index] def getChar(data,index): # return one byte from data as a signed char result = data[index] if result > 127:
result -= 256
return result
def getUChar(data,index):
# return one byte from data as an unsigned char
result = data[index] & 0xFF
return result
def readBME280ID(addr=DEVICE):
# Chip ID Register Address
REG_ID = 0xD0
(chip_id, chip_version) = bus.read_i2c_block_data(addr, REG_ID, 2)
return (chip_id, chip_version)
def readBME280All(addr=DEVICE):
# Register Addresses
REG_DATA = 0xF7
REG_CONTROL = 0xF4
REG_CONFIG = 0xF5
REG_CONTROL_HUM = 0xF2
REG_HUM_MSB = 0xFD
REG_HUM_LSB = 0xFE
# Oversample setting - page 27
OVERSAMPLE_TEMP = 2
OVERSAMPLE_PRES = 2
MODE = 1
# Oversample setting for humidity register - page 26
OVERSAMPLE_HUM = 2
bus.write_byte_data(addr, REG_CONTROL_HUM, OVERSAMPLE_HUM)
control = OVERSAMPLE_TEMP<<5 | OVERSAMPLE_PRES<<2 | MODE
bus.write_byte_data(addr, REG_CONTROL, control)
# Read blocks of calibration data from EEPROM
# See Page 22 data sheet
cal1 = bus.read_i2c_block_data(addr, 0x88, 24)
cal2 = bus.read_i2c_block_data(addr, 0xA1, 1)
cal3 = bus.read_i2c_block_data(addr, 0xE1, 7)
# Convert byte data to word values
dig_T1 = getUShort(cal1, 0)
dig_T2 = getShort(cal1, 2)
dig_T3 = getShort(cal1, 4)
dig_P1 = getUShort(cal1, 6)
dig_P2 = getShort(cal1, 8)
dig_P3 = getShort(cal1, 10)
dig_P4 = getShort(cal1, 12)
dig_P5 = getShort(cal1, 14)
dig_P6 = getShort(cal1, 16)
dig_P7 = getShort(cal1, 18)
dig_P8 = getShort(cal1, 20)
dig_P9 = getShort(cal1, 22)
dig_H1 = getUChar(cal2, 0)
dig_H2 = getShort(cal3, 0)
dig_H3 = getUChar(cal3, 2)
dig_H4 = getChar(cal3, 3)
dig_H4 = (dig_H4 << 24) >> 20
dig_H4 = dig_H4 | (getChar(cal3, 4) & 0x0F)
dig_H5 = getChar(cal3, 5)
dig_H5 = (dig_H5 << 24) >> 20
dig_H5 = dig_H5 | (getUChar(cal3, 4) >> 4 & 0x0F)
dig_H6 = getChar(cal3, 6)
# Read temperature/pressure/humidity
data = bus.read_i2c_block_data(addr, REG_DATA, 8)
pres_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4)
temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4)
hum_raw = (data[6] << 8) | data[7] #Refine temperature var1 = ((((temp_raw>>3)-(dig_T1<<1)))*(dig_T2)) >> 11
var2 = (((((temp_raw>>4) - (dig_T1)) * ((temp_raw>>4) - (dig_T1))) >> 12) * (dig_T3)) >> 14
t_fine = var1+var2
temperature = float(((t_fine * 5) + 128) >> 8);
# Refine pressure and adjust for temperature
var1 = t_fine / 2.0 - 64000.0
var2 = var1 * var1 * dig_P6 / 32768.0
var2 = var2 + var1 * dig_P5 * 2.0
var2 = var2 / 4.0 + dig_P4 * 65536.0
var1 = (dig_P3 * var1 * var1 / 524288.0 + dig_P2 * var1) / 524288.0
var1 = (1.0 + var1 / 32768.0) * dig_P1
if var1 == 0:
pressure=0
else:
pressure = 1048576.0 - pres_raw
pressure = ((pressure - var2 / 4096.0) * 6250.0) / var1
var1 = dig_P9 * pressure * pressure / 2147483648.0
var2 = pressure * dig_P8 / 32768.0
pressure = pressure + (var1 + var2 + dig_P7) / 16.0
# Refine humidity
humidity = t_fine - 76800.0
humidity = (hum_raw - (dig_H4 * 64.0 + dig_H5 / 16384.0 * humidity)) * (dig_H2 / 65536.0 * (1.0 + dig_H6 / 67108864.0 * humidity * (1.0 + dig_H3 / 67108864.0 * humidity)))
humidity = humidity * (1.0 - dig_H1 * humidity / 524288.0)
if humidity > 100:
humidity = 100
elif humidity < 0:
humidity = 0
return temperature/100.0,pressure/100.0,humidity
def main():
(chip_id, chip_version) = readBME280ID()
print "Chip ID :", chip_id
print "Version :", chip_version
temperature,pressure,humidity = readBME280All()
print "Temperature : ", temperature, "C"
print "Pressure : ", pressure, "hPa"
print "Humidity : ", humidity, "%"
temperature_str = str(temperature)
humidity_str = str(humidity)
pressure_str = str(pressure)
update_bm280_sensor_in_domoticz("http://" + ip_domoticz + "/json.htm?type=command¶m=udevice&idx=" + idx_dummy_bme280 + "&nvalue=0&svalue=" + temperature_str + ";" + humidity_str + ";0;" + pressure_str + ";0")
if __name__=="__main__":
main()