threaded cyclic data aquisition implemented

__init__.py

@@ -1,44 +1,5 @@
-try:
+import logging
-    from config import dht_gpio
-except ImportError:
-    dht_gpio = None
-
-try:
-    import Adafruit_DHT as dht
-except ImportError:
-    dht = None
-
-try:
-    import Adafruit_BMP.BMP085 as bmp
-except ImportError:
-    bmp = None
-
-#TODO: background process for value sensing (every x seconds)
-
-KEY_TEMPERATURE = 't'
-KEY_HUMIDITY = 'h'
-KEY_PRESSURE = 'p'
 
 
-class EnvSens(object):
+logger_name = 'RPI_ENVSENS'
-    def __init__(self):
+logger = logging.getLogger(logger_name)
-        if bmp is not None:
-            self.bmp = bmp.BMP085()
-
-    def get_env_data(self):
-        #
-        # DHT22
-        #
-        if dht is None or dht_gpio is None:
-            h = -17.3
-            t = -125.7
-        else:
-            h, t = dht.read_retry(dht.DHT22, dht_gpio)
-        #
-        # BMP180
-        #
-        if bmp is None:
-            p = -1024.17
-        else:
-            p = self.bmp.read_pressure()/100.
-        return {KEY_TEMPERATURE: t, KEY_HUMIDITY: h, KEY_PRESSURE: p}

bmp.py

@@ -0,0 +1,141 @@
+# Distributed with a free-will license.
+# Use it any way you want, profit or free, provided it fits in the licenses of its associated works.
+# BMP180
+# This code is designed to work with the BMP180_I2CS I2C Mini Module available from ControlEverything.com.
+# https://www.controleverything.com/content/Pressure?sku=BMP180_I2CS#tabs-0-product_tabset-2
+
+import smbus
+import threading
+import time
+
+from . import logger
+
+
+class bmp_180(object):
+	KEY_TEMPERATURE = 'temperature'
+	KEY_PRESSURE = 'pressure'
+	KEY_TIME = 'time'
+	
+	def __init__(self, data_callback=None):
+		self.__data_callback__ = data_callback
+		# Initial the dht device, with data pin connected to:
+		self.__active__ = True
+		self.__thread__ = threading.Thread(target=self.run, args=())
+		self.__thread__.daemon = True                            # Daemonize thread
+		self.__thread__.start()                                  # Start the execution
+	
+	def run(self):
+		while self.__active__:
+			data = self.__bmp_data_transmission__()
+			if data is not None:
+				logger.debug('BMP-Communication: Successfully: %s', repr(data))
+				if self.__data_callback__ is not None:
+					self.__data_callback__(**data)
+			time.sleep(0.5)
+	
+	def close(self):
+		self.__active__ = False
+		self.__thread__.join()
+	
+	def __del__(self):
+		self.close()
+	
+	def __bmp_data_transmission__(self):
+		rv = {}
+		# Get I2C bus
+		bus = smbus.SMBus(1)
+		
+		# BMP180 address, 0x77(119)
+		# Read data back from 0xAA(170), 22 bytes
+		data = bus.read_i2c_block_data(0x77, 0xAA, 22)
+		
+		# Convert the data
+		AC1 = data[0] * 256 + data[1]
+		if AC1 > 32767 :
+			AC1 -= 65535
+		AC2 = data[2] * 256 + data[3]
+		if AC2 > 32767 :
+			AC2 -= 65535
+		AC3 = data[4] * 256 + data[5]
+		if AC3 > 32767 :
+			AC3 -= 65535
+		AC4 = data[6] * 256 + data[7]
+		AC5 = data[8] * 256 + data[9]
+		AC6 = data[10] * 256 + data[11]
+		B1 = data[12] * 256 + data[13]
+		if B1 > 32767 :
+			B1 -= 65535
+		B2 = data[14] * 256 + data[15]
+		if B2 > 32767 :
+			B2 -= 65535
+		MB = data[16] * 256 + data[17]
+		if MB > 32767 :
+			MB -= 65535
+		MC = data[18] * 256 + data[19]
+		if MC > 32767 :
+			MC -= 65535
+		MD = data[20] * 256 + data[21]
+		if MD > 32767 :
+			MD -= 65535
+		
+		time.sleep(0.5)
+		
+		# BMP180 address, 0x77(119)
+		# Select measurement control register, 0xF4(244)
+		#		0x2E(46)	Enable temperature measurement
+		bus.write_byte_data(0x77, 0xF4, 0x2E)
+		
+		time.sleep(0.5)
+		
+		# BMP180 address, 0x77(119)
+		# Read data back from 0xF6(246), 2 bytes
+		# temp MSB, temp LSB
+		data = bus.read_i2c_block_data(0x77, 0xF6, 2)
+		
+		# Convert the data
+		temp = data[0] * 256 + data[1]
+		
+		# BMP180 address, 0x77(119)
+		# Select measurement control register, 0xF4(244)
+		#		0x74(116)	Enable pressure measurement, OSS = 1
+		bus.write_byte_data(0x77, 0xF4, 0x74)
+		
+		time.sleep(0.5)
+		
+		# BMP180 address, 0x77(119)
+		# Read data back from 0xF6(246), 3 bytes
+		# pres MSB1, pres MSB, pres LSB
+		data = bus.read_i2c_block_data(0x77, 0xF6, 3)
+		
+		rv[self.KEY_TIME] = time.time()
+	
+		# Convert the data
+		pres = ((data[0] * 65536) + (data[1] * 256) + data[2]) / 128
+		# Callibration for Temperature
+		X1 = (temp - AC6) * AC5 / 32768.0
+		X2 = (MC * 2048.0) / (X1 + MD)
+		B5 = X1 + X2
+		rv[self.KEY_TEMPERATURE] = ((B5 + 8.0) / 16.0) / 10.0
+		
+		# Calibration for Pressure
+		B6 = B5 - 4000
+		X1 = (B2 * (B6 * B6 / 4096.0)) / 2048.0
+		X2 = AC2 * B6 / 2048.0
+		X3 = X1 + X2
+		B3 = (((AC1 * 4 + X3) * 2) + 2) / 4.0
+		X1 = AC3 * B6 / 8192.0
+		X2 = (B1 * (B6 * B6 / 2048.0)) / 65536.0
+		X3 = ((X1 + X2) + 2) / 4.0
+		B4 = AC4 * (X3 + 32768) / 32768.0
+		B7 = ((pres - B3) * (25000.0))
+		pressure = 0.0
+		if B7 < 2147483648:
+			pressure = (B7 * 2) / B4
+		else :
+			pressure = (B7 / B4) * 2
+		X1 = (pressure / 256.0) * (pressure / 256.0)
+		X1 = (X1 * 3038.0) / 65536.0
+		X2 = ((-7357) * pressure) / 65536.0
+		rv[self.KEY_PRESSURE] = (pressure + (X1 + X2 + 3791) / 16.0) / 100
+	
+		return rv

dht.py

@@ -0,0 +1,55 @@
+import adafruit_dht
+import threading
+import time
+
+from . import logger
+
+
+class dht_22(object):
+    KEY_TEMPERATURE = 'temperature'
+    KEY_HUMIDITY = 'humidity'
+    KEY_TIME = 'time'
+
+    def __init__(self, gpio, data_callback=None):
+        self.__data_callback__ = data_callback
+        # Initial the dht device, with data pin connected to:
+        self.__dht_device__ = adafruit_dht.DHT22(gpio)
+        self.__active__ = True
+        self.__thread__ = threading.Thread(target=self.run, args=())
+        self.__thread__.daemon = True                            # Daemonize thread
+        self.__thread__.start()                                  # Start the execution
+
+    def run(self):
+        while self.__active__:
+            data = self.__dht_data_transmission__()
+            if data is not None:
+                logger.debug('DHT-Communication: Successfully: %s', repr(data))
+                if self.__data_callback__ is not None:
+                    self.__data_callback__(**data)
+            time.sleep(2.0)
+
+    def close(self):
+        self.__active__ = False
+        self.__thread__.join()
+
+    def __del__(self):
+        self.close()
+
+    def __dht_data_transmission__(self):
+        while self.__active__:
+            try:
+                # Store the values
+                data = {}
+                data[self.KEY_TEMPERATURE] = self.__dht_device__.temperature
+                data[self.KEY_HUMIDITY] = self.__dht_device__.humidity
+                data[self.KEY_TIME] = time.time()
+                if data[self.KEY_TEMPERATURE] is not None and data[self.KEY_HUMIDITY] is not None:
+                    return data
+                time.sleep(2.0)
+            except RuntimeError as error:
+                # Errors happen fairly often, DHT's are hard to read, just keep going
+                logger.debug('DHT-Communication: ' + error.args[0])
+                time.sleep(0.1)
+            except Exception as error:
+                self.__dht_device__.exit()
+                raise error