Add python script and dependencies

bh1750.py

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+#!/usr/bin/python
+import smbus
+import time
+
+# Define some constants from the datasheet
+
+DEVICE     = 0x23 # Default device I2C address
+
+POWER_DOWN = 0x00 # No active state
+POWER_ON   = 0x01 # Power on
+RESET      = 0x07 # Reset data register value
+
+# Start measurement at 4lx resolution. Time typically 16ms.
+CONTINUOUS_LOW_RES_MODE = 0x13
+# Start measurement at 1lx resolution. Time typically 120ms
+CONTINUOUS_HIGH_RES_MODE_1 = 0x10
+# Start measurement at 0.5lx resolution. Time typically 120ms
+CONTINUOUS_HIGH_RES_MODE_2 = 0x11
+# Start measurement at 1lx resolution. Time typically 120ms
+# Device is automatically set to Power Down after measurement.
+ONE_TIME_HIGH_RES_MODE_1 = 0x20
+# Start measurement at 0.5lx resolution. Time typically 120ms
+# Device is automatically set to Power Down after measurement.
+ONE_TIME_HIGH_RES_MODE_2 = 0x21
+# Start measurement at 1lx resolution. Time typically 120ms
+# Device is automatically set to Power Down after measurement.
+ONE_TIME_LOW_RES_MODE = 0x23
+
+#bus = smbus.SMBus(0) # Rev 1 Pi uses 0
+bus = smbus.SMBus(1)  # Rev 2 Pi uses 1
+
+def convertToNumber(data):
+  # Simple function to convert 2 bytes of data
+  # into a decimal number
+  return ((data[1] + (256 * data[0])) / 1.2)
+
+def readLight(addr=DEVICE):
+  data = bus.read_i2c_block_data(addr,ONE_TIME_HIGH_RES_MODE_1)
+  return convertToNumber(data)
+
+def main():
+
+  while True:
+    print ("Light Level : " + str(readLight()) + " lx")
+    time.sleep(0.5)
+
+if __name__=="__main__":
+   main()

bme280.py

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+#!/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
+#
+# http://www.raspberrypi-spy.co.uk/
+#
+#--------------------------------------
+import smbus
+import time
+from ctypes import c_short
+from ctypes import c_byte
+from ctypes import c_ubyte
+
+DEVICE = 0x76 # Default device I2C address
+
+
+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)
+
+  # Wait in ms (Datasheet Appendix B: Measurement time and current calculation)
+  wait_time = 1.25 + (2.3 * OVERSAMPLE_TEMP) + ((2.3 * OVERSAMPLE_PRES) + 0.575) + ((2.3 * OVERSAMPLE_HUM)+0.575)
+  time.sleep(wait_time/1000)  # Wait the required time  
+
+  # 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, "%")
+
+if __name__=="__main__":
+   main()

i2c2mqtt.py

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+#!/usr/bin/env python3
+# -*- coding: latin-1 -*-
+#
+#  i2c2mqtt.py
+#
+#  Copyright 2016 Sébastien Lucas <[email protected]>
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+import bh1750
+import bme280
+import si7201
+import time, json, argparse
+import paho.mqtt.publish as publish # pip install paho-mqtt
+
+verbose = False
+
+def debug(msg):
+  if verbose:
+    print (msg + "\n")
+
+def getI2cSensors(devices):
+  tstamp = int(time.time())
+
+  newObject = {"time": tstamp}
+
+  if not isinstance(devices, list):
+    newObject['message'] = 'No devices specified.'
+    return (False, newObject)
+
+  if 'bh750' in devices:
+    ###### Get luminosity ##
+    lux = bh1750.readLight()
+    # Drop the first (usually bad)
+    lux = bh1750.readLight()
+    newObject['lum'] = int (lux)
+    debug ("Light Level : " + str(newObject['lum']) + " lx")
+
+  if 'si7201' in devices:
+    ###### Get temperature & humidity from si7201 ##
+    T = si7201.readTemperature()
+    newObject['temp'] = round (T, 1)
+    RH = si7201.readHumidity()
+    newObject['hum'] = int (RH)
+    debug ("Temperature : " + str(newObject['temp']) + " °C")
+    debug ("Humidity : " + str(newObject['hum']) + " %")
+
+  if 'bme280' in devices:
+    ###### Get temperature, pressure & humidity from bme280 ##
+    T, P, RH = bme280.readBME280All()
+    newObject['temp'] = round (T, 1)
+    newObject['hum'] = int (RH)
+    newObject['pres'] = int(P)
+    debug ("Temperature : " + str(newObject['temp']) + " °C")
+    debug ("Humidity : " + str(newObject['hum']) + " %")
+    debug ("Pressure : " + str(newObject['pres']) + " hPa")
+
+  return (True, newObject)
+
+parser = argparse.ArgumentParser(description='Read current temperature,illuminance and humidity from i2c sensors and send them to a MQTT broker.')
+parser.add_argument('-d', '--device', dest='devices', action="append",
+                   help='Specify the devices to probe in the I2C bus. Can be called many times.')
+parser.add_argument('-m', '--mqtt-host', dest='host', action="store", default="127.0.0.1",
+                   help='Specify the MQTT host to connect to.')
+parser.add_argument('-n', '--dry-run', dest='dryRun', action="store_true", default=False,
+                   help='No data will be sent to the MQTT broker.')
+parser.add_argument('-t', '--topic', dest='topic', action="store", default="sensor/i2c",
+                   help='The MQTT topic on which to publish the message (if it was a success).')
+parser.add_argument('-T', '--topic-error', dest='topicError', action="store", default="error/sensor/i2c", metavar="TOPIC",
+                   help='The MQTT topic on which to publish the message (if it wasn\'t a success).')
+parser.add_argument('-v', '--verbose', dest='verbose', action="store_true", default=False,
+                   help='Enable debug messages.')
+
+args = parser.parse_args()
+verbose = args.verbose;
+
+status, data = getI2cSensors(args.devices)
+jsonString = json.dumps(data)
+if status:
+  debug("Success with message (for current readings) <{0}>".format(jsonString))
+  if not args.dryRun:
+    publish.single(args.topic, jsonString, hostname=args.host)
+else:
+  debug("Failure with message <{0}>".format(jsonString))
+  if not args.dryRun:
+    publish.single(args.topicError, jsonString, hostname=args.host)

si7201.py

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+#!/usr/bin/python
+# -*- coding: latin-1 -*-
+
+import smbus
+bus = smbus.SMBus(1)
+address = 0x40
+
+def crc(data):
+  rem = 0
+  for b in data:
+    rem ^= b
+    for bit in range(8):
+      if rem & 128:
+        rem = (rem << 1) ^ 0x31
+      else:
+        rem = (rem << 1)
+  return rem & 0xFF
+
+def readTemperature():
+  r = bus.read_i2c_block_data(address,0xE3)
+  t_val = (r[0]<<8) + r[1]
+  return ((175.72 * t_val)/65536.0) - 46.85
+
+def readHumidity():
+  r = bus.read_i2c_block_data(address,0xE5)
+  rh_val = (r[0]<<8) + r[1]
+  return ((125.0 * rh_val)/65536.0) - 6.0
+
+def main():
+  print ("Temperature : " + str(readTemperature()) + " °C")
+  print ("Humidity : " + str(readHumidity()) + " %")
+
+if __name__=="__main__":
+   main()
+