Improve bus selection

Added *args, **argk parameters to several functions and methods in order to pass through bus selection parameters
linux_i2c.py accepts iBus as a parameter
micropython_i2c.py and circuitpy_i2c.py both accept sda, scl, and freq as parameters

Author: sfe-SparkFro

qwiic_i2c/__init__.py

@@ -91,7 +91,7 @@
 #
 # If no driver is found, a None value is returned
 
-def getI2CDriver():
+def getI2CDriver(*args, **argk):
 	"""
 	.. function:: getI2CDriver()
 
@@ -119,13 +119,13 @@ def getI2CDriver():
 		# Does this class/driverd support this platform?
 		if driverClass.isPlatform():
 
-			_theDriver = driverClass()
+			_theDriver = driverClass(*args, **argk)
 			# Yes - return the driver object
 			return _theDriver
 
 	return None
 
-def get_i2c_driver():
+def get_i2c_driver(*args, **argk):
 	"""
 	.. function:: get_i2c_driver()
 
@@ -140,12 +140,12 @@ def get_i2c_driver():
 		>>> i2cDriver = qwiic_i2c.get_i2c_driver()
 		>>> myData = i2cDriver.readByte(0x73, 0x34)
 	"""
-	return getI2CDriver()
+	return getI2CDriver(*args, **argk)
 
 #-------------------------------------------------
 # Method to determine if a particular device (at the provided address)
 # is connected to the bus.
-def isDeviceConnected(devAddress):
+def isDeviceConnected(devAddress, *args, **argk):
 	"""
 	.. function:: isDeviceConnected()
 
@@ -158,15 +158,15 @@ def isDeviceConnected(devAddress):
 		:rtype: bool
 
 	"""
-	i2c = getI2CDriver()
+	i2c = getI2CDriver(*args, **argk)
 
 	if not i2c:
 		print("Unable to load the I2C driver for this device")
 		return False
 
 	return i2c.isDeviceConnected(devAddress)
 
-def is_device_connected(devAddress):
+def is_device_connected(devAddress, *args, **argk):
 	"""
 	.. function:: is_device_connected()
 
@@ -179,12 +179,12 @@ def is_device_connected(devAddress):
 		:rtype: bool
 
 	"""
-	return isDeviceConnected(devAddress)
+	return isDeviceConnected(devAddress, *args, **argk)
 
 #-------------------------------------------------
 # Method to determine if a particular device (at the provided address)
 # is connected to the bus.
-def ping(devAddress):
+def ping(devAddress, *args, **argk):
 	"""
 	.. function:: ping()
 
@@ -197,4 +197,4 @@ def ping(devAddress):
 		:rtype: bool
 
 	"""
-	return isDeviceConnected(devAddress)
+	return isDeviceConnected(devAddress, *args, **argk)

qwiic_i2c/circuitpy_i2c.py

@@ -49,7 +49,7 @@
 # Attempts to fail elegantly. Put this in a central place to support 
 # error handling  -- especially on non-circuitpy platforms
 #
-def _connectToI2CBus():
+def _connectToI2CBus(sda=None, scl=None, freq=100000, *args, **argk):
 
 	try:
 		import board
@@ -65,10 +65,12 @@ def _connectToI2CBus():
 	# Connect - catch errors 
 
 	try:
-		if hasattr(board, "STEMMA_I2C"):
+		if sda != None and scl != None:
+			daBus = busio.I2C(scl, sda, frequency=freq)
+		elif hasattr(board, "STEMMA_I2C"):
 			daBus = board.STEMMA_I2C()
 		else:
-			daBus = busio.I2C(board.SCL, board.SDA)
+			daBus = busio.I2C(board.SCL, board.SDA, frequency=freq)
 	except Exception as ee:
 		if type(ee) is RuntimeError:
 			print("Error:\tUnable to connect to I2C bus. %s" % (ee))
@@ -85,8 +87,8 @@ def _connectToI2CBus():
 
 	return daBus
 
-def _connect_to_i2c_bus():
-	return _connectToI2CBus()
+def _connect_to_i2c_bus(*args, **argk):
+	return _connectToI2CBus(*args, **argk)
 
 # notes on determining CirPy platform
 #
@@ -100,12 +102,16 @@ class CircuitPythonI2C(I2CDriver):
 
 	_i2cbus = None
 
-	def __init__(self):
+	def __init__(self, sda=None, scl=None, freq=100000, *args, **argk):
 
 		# Call the super class. The super calss will use default values if not 
 		# proviced
 		I2CDriver.__init__(self)
 
+		self._sda = sda
+		self._scl = scl
+		self._freq = freq
+
 	# Okay, are we running on a circuit py system?
 	@classmethod
 	def isPlatform(cls):
@@ -128,7 +134,7 @@ def __getattr__(self, name):
 
 		if(name == "i2cbus"):
 			if( self._i2cbus == None):
-				self._i2cbus = _connectToI2CBus()
+				self._i2cbus = _connectToI2CBus(sda=self._sda, scl=self._scl, freq=self._freq)
 			return self._i2cbus
 
 		else:
@@ -284,53 +290,32 @@ def writeBlock(self, address, commandCode, value):
 	def write_block(self, address, commandCode, value):
 		return self.writeBlock(address, commandCode, value)
 
-	@classmethod
-	def isDeviceConnected(cls, devAddress):
-		if cls._i2cbus == None:
-			cls._i2cbus = _connectToI2CBus()
-		if cls._i2cbus == None:
-			return False
-		if not cls._i2cbus.try_lock():
-			return False
-
+	def isDeviceConnected(self, devAddress):
 		isConnected = False
 		try:
 			# Try to write nothing to the device
 			# If it throws an I/O error - the device isn't connected
-			cls._i2cbus.writeto(devAddress, bytearray())
+			self.i2cbus.writeto(devAddress, bytearray())
 			isConnected = True
 		except Exception as ee:
 			print("Error connecting to Device: %X, %s" % (devAddress, ee))
 			pass
 		finally:
-			cls._i2cbus.unlock()
+			self.i2cbus.unlock()
 
 		return isConnected
 
-	@classmethod
-	def is_device_connected(cls, devAddress):
+	def is_device_connected(self, devAddress):
 		return cls.isDeviceConnected(devAddress)
 
-	@classmethod
-	def ping(cls, devAddress):
+	def ping(self, devAddress):
 		return cls.isDeviceConnected(devAddress)
 
 	#-----------------------------------------------------------------------
 	# scan()
 	#
 	# Scans the I2C bus and returns a list of addresses that have a devices connected
 	#
-	@classmethod
-	def scan(cls):
+	def scan(self):
 		""" Returns a list of addresses for the devices connected to the I2C bus."""
-
-		if cls._i2cbus == None:
-			cls._i2cbus = _connectToI2CBus()
-		if cls._i2cbus == None:
-			return []
-		if not cls._i2cbus.try_lock():
-			return []
-
-		result = cls._i2cbus.scan()
-		cls._i2cbus.unlock()
-		return result
+		return self.i2cbus.scan()

qwiic_i2c/i2c_driver.py

@@ -78,7 +78,7 @@ class I2CDriver(object):
 	# stubs
 	name = 'qwiic I2C abstract base class'
 
-	def __init__(self):
+	def __init__(self, *args, **argk):
 		pass
 
 
@@ -313,8 +313,7 @@ def write_block(self, address, commandCode, value):
 		"""
 		return None
 
-	@classmethod
-	def isDeviceConnected(cls, devAddress):
+	def isDeviceConnected(self, devAddress):
 		"""
 			Determines if a particular device (at the provided address)
 			is connected to the bus.
@@ -327,8 +326,7 @@ def isDeviceConnected(cls, devAddress):
 		"""
 		return None
 
-	@classmethod
-	def is_device_connected(cls, devAddress):
+	def is_device_connected(self, devAddress):
 		"""
 			Determines if a particular device (at the provided address)
 			is connected to the bus.
@@ -341,8 +339,7 @@ def is_device_connected(cls, devAddress):
 		"""
 		return None
 
-	@classmethod
-	def ping(cls, devAddress):
+	def ping(self, devAddress):
 		"""
 			Determines if a particular device (at the provided address)
 			is connected to the bus.
@@ -355,8 +352,7 @@ def ping(cls, devAddress):
 		"""
 		return None
 
-	@classmethod
-	def scan(cls):
+	def scan(self):
 		"""
 			Used to scan the I2C bus, returning a list of I2C address attached to the computer.
 

qwiic_i2c/linux_i2c.py

@@ -50,15 +50,14 @@
 # Attempts to fail elegantly - often an issue with permissions with the I2C 
 # bus. Users of this system should be added to the system i2c group
 #
-def _connectToI2CBus():
+def _connectToI2CBus(iBus=1, *args, **argk):
 
 	try:
 		import smbus2
 	except Exception as ee:
 		print("Error: Unable to load smbus module. Unable to continue", file=sys.stderr)
 		return None
 
-	iBus = 1
 	daBus = None
 
 	error=False
@@ -82,8 +81,8 @@ def _connectToI2CBus():
 
 	return daBus
 
-def _connect_to_i2c_bus():
-	return _connectToI2CBus()
+def _connect_to_i2c_bus(*args, **argk):
+	return _connectToI2CBus(*args, **argk)
 
 # notes on determining Linux platform
 #
@@ -103,13 +102,13 @@ class LinuxI2C(I2CDriver):
 	_i2cbus = None
 	_i2c_msg = None
 
-	def __init__(self):
+	def __init__(self, iBus=1, *args, **argk):
 
 		# Call the super class. The super calss will use default values if not 
 		# proviced
 		I2CDriver.__init__(self)
 
-
+		self._iBus = iBus
 
 	# Okay, are we running on a Linux system?
 	@classmethod
@@ -131,7 +130,7 @@ def __getattr__(self, name):
 
 		if(name == "i2cbus"):
 			if( self._i2cbus == None):
-				self._i2cbus = _connectToI2CBus()
+				self._i2cbus = _connectToI2CBus(self._iBus)
 			return self._i2cbus
 
 		else:
@@ -254,65 +253,33 @@ def writeBlock(self, address, commandCode, value):
 	def write_block(self, address, commandCode, value):
 		return self.writeBlock(address, commandCode, value)
 
-	@classmethod
-	def isDeviceConnected(cls, devAddress):
-		if cls._i2cbus == None:
-			cls._i2cbus = _connectToI2CBus()
-		
-		if cls._i2cbus == None:
-			return False
-		
+	def isDeviceConnected(self, devAddress):
 		isConnected = False
 		try:
 			# Try to write nothing to the device
 			# If it throws an I/O error - the device isn't connected
-			cls._i2cbus.write_quick(devAddress)
+			self.i2cbus.write_quick(devAddress)
 			isConnected = True
 		except Exception as ee:
 			print("Error connecting to Device: %X, %s" % (devAddress, ee))
 			pass
 
 		return isConnected
 
-	@classmethod
-	def is_device_connected(cls, devAddress):
-		return cls.isDeviceConnected(devAddress)
+	def is_device_connected(self, devAddress):
+		return self.isDeviceConnected(devAddress)
 
-	@classmethod
-	def ping(cls, devAddress):
-		return cls.isDeviceConnected(devAddress)
+	def ping(self, devAddress):
+		return self.isDeviceConnected(devAddress)
 
 	#-----------------------------------------------------------------------
 	# scan()
 	#
 	# Scans the I2C bus and returns a list of addresses that have a devices connected
 	#
-	@classmethod
-	def scan(cls):
+	def scan(self):
 		""" Returns a list of addresses for the devices connected to the I2C bus."""
-	
-		# The plan - loop through the I2C address space and read a byte. If an 
-		# OSError occures, a device isn't at that address. 
-	
-		if cls._i2cbus == None:
-			cls._i2cbus = _connectToI2CBus()
-	
-		if cls._i2cbus == None:
-			return []
-	
-		foundDevices = []
-	
-		# Loop over the address space - which is 7 bits (0-127 range)
-		for currAddress in range(0, 128):
-			try:
-				cls._i2cbus.read_byte(currAddress)
-			except Exception:
-				continue
-	
-			foundDevices.append(currAddress)
-	
-	
-		return foundDevices
+		return self.i2cbus.scan()
 
 	#-----------------------------------------------------------------------
 	# Custom method for reading +8-bit register using `i2c_msg` from `smbus2`