Merge pull request #3 from sparkfun/micropython-rp2040

add micropython RP2040 i2c driver

Author: gigapod

qwiic_i2c/__init__.py

@@ -63,11 +63,26 @@
 #
 #-----------------------------------------------------------------------------
 # Drivers and driver baseclass
-from .i2c_driver 	import I2CDriver
-from .linux_i2c 	import LinuxI2C
-from .circuitpy_i2c import CircuitPythonI2C
+from .i2c_driver import I2CDriver
 
-_drivers = [LinuxI2C, CircuitPythonI2C]
+# All supported platform module and class names
+_supported_platforms = {
+	"linux_i2c": "LinuxI2C",
+	"circuitpy_i2c": "CircuitPythonI2C",
+	"micropython_i2c": "MicroPythonI2C"
+}
+
+# List of platform drivers found on this system
+_drivers = []
+
+# Loop through all supported platform drivers, see if they're included, and
+# append them to the driver list if so
+for module_name, class_name in _supported_platforms.items():
+	try:
+		sub_module = __import__("qwiic_i2c." + module_name, None, None, [None])
+		_drivers.append(getattr(sub_module, class_name))
+	except:
+		pass
 
 _theDriver = None
 

qwiic_i2c/micropython_i2c.py

@@ -0,0 +1,135 @@
+#-----------------------------------------------------------------------------
+# micropython_i2c.py
+#
+# Encapsulate MicroPython port I2C interface
+#------------------------------------------------------------------------
+#
+# Written by  oclyke, Feb 2021
+# 
+#
+# More information on qwiic is at https://www.sparkfun.com/qwiic
+#
+# Do you like this library? Help support SparkFun. Buy a board!
+#
+#==================================================================================
+# Copyright (c) 2021 SparkFun Electronics
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy 
+# of this software and associated documentation files (the "Software"), to deal 
+# in the Software without restriction, including without limitation the rights 
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
+# copies of the Software, and to permit persons to whom the Software is 
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all 
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
+# SOFTWARE.
+#==================================================================================
+
+from .i2c_driver import I2CDriver
+
+import sys
+
+_PLATFORM_NAME = "MicroPython"
+
+# used internally in this file to get i2c class object 
+def _connectToI2CBus(freq=400000):
+	try:
+		from machine import I2C, Pin
+		# Todo: Don't hard code I2C pin and port!
+		return I2C(id=1, scl=Pin(19), sda=Pin(18), freq=freq)
+	except Exception as e:
+		print(str(e))
+		print('error: failed to connect to i2c bus')
+	return None
+
+class MicroPythonI2C(I2CDriver):
+
+	# Constructor
+	name = _PLATFORM_NAME
+	_i2cbus = None
+
+	def __init__(self):
+		I2CDriver.__init__(self) # init super
+
+	@classmethod
+	def isPlatform(cls):
+		try:
+			return sys.implementation.name == 'micropython'
+		except:
+			return False
+
+
+#-------------------------------------------------------------------------		
+	# General get attribute method
+	#
+	# Used to intercept getting the I2C bus object - so we can perform a lazy
+	# connect ....
+	#
+	def __getattr__(self, name):
+
+		if(name == "i2cbus"):
+			if( self._i2cbus == None):
+				self._i2cbus = _connectToI2CBus()
+			return self._i2cbus
+
+		else:
+			# Note - we call __getattribute__ to the super class (object).
+			return super(I2CDriver, self).__getattribute__(name)
+
+	#-------------------------------------------------------------------------
+	# General set attribute method
+	#
+	# Basically implemented to make the i2cbus attribute readonly to users 
+	# of this class. 
+	#
+	def __setattr__(self, name, value):
+
+		if(name != 'i2cbus'):
+			super(I2CDriver, self).__setattr__(name, value)
+
+	# read commands ----------------------------------------------------------
+	def readWord(self, address, commandCode):
+		buffer = self.i2cbus.readfrom_mem(address, commandCode, 2)
+		return (buffer[1] << 8 ) | buffer[0]
+
+	def readByte(self, address, commandCode):
+		return self.i2cbus.readfrom_mem(address, commandCode, 1)[0]
+
+	def readBlock(self, address, commandCode, nBytes):
+		return self.i2cbus.readfrom_mem(address, commandCode, nBytes)
+
+		
+	# write commands----------------------------------------------------------
+	def writeCommand(self, address, commandCode):
+		self.i2cbus.writeto(address, commandCode.to_bytes(1, 'little'))
+
+	def writeWord(self, address, commandCode, value):
+		self.i2cbus.writeto_mem(address, commandCode, value.to_bytes(2, 'little'))
+
+	def writeByte(self, address, commandCode, value):
+		self.i2cbus.writeto_mem(address, commandCode, value.to_bytes(1, 'little'))
+
+	def writeBlock(self, address, commandCode, value):
+		self.i2cbus.writeto_mem(address, commandCode, bytes(value))
+
+
+	# scan -------------------------------------------------------------------
+	@classmethod
+	def scan(cls):
+		""" 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 []
+			
+		return cls._i2cbus.scan()