Merge pull request #22 from sparkfun/feature/add_no_addr_reads

Feature/add no addr reads

Author: malcolm-sparkfun

qwiic_i2c/circuitpy_i2c.py

@@ -162,7 +162,10 @@ def readWord(self, address, commandCode):
 		buffer = bytearray(2)
 
 		try:
-			self._i2cbus.writeto_then_readfrom(address, bytes([commandCode]), buffer)
+			if (commandCode == None):
+				self._i2cbus.readfrom_into(address, buffer)
+			else:
+				self._i2cbus.writeto_then_readfrom(address, bytes([commandCode]), buffer)
 		except Exception as e:
 			self._i2cbus.unlock()
 			raise e
@@ -176,14 +179,17 @@ def read_word(self, address, commandCode):
 		return self.readWord(address, commandCode)
 
 	#----------------------------------------------------------
-	def readByte(self, address, commandCode):
+	def readByte(self, address, commandCode = None):
 		if not self._i2cbus.try_lock():
 			raise Exception("Unable to lock I2C bus")
 
 		buffer = bytearray(1)
 
 		try:
-			self._i2cbus.writeto_then_readfrom(address, bytes([commandCode]), buffer)
+			if (commandCode == None):
+				self._i2cbus.readfrom_into(address, buffer)
+			else:
+				self._i2cbus.writeto_then_readfrom(address, bytes([commandCode]), buffer)
 		except Exception as e:
 			self._i2cbus.unlock()
 			raise e
@@ -203,7 +209,10 @@ def readBlock(self, address, commandCode, nBytes):
 		buffer = bytearray(nBytes)
 
 		try:
-			self._i2cbus.writeto_then_readfrom(address, bytes([commandCode]), buffer)
+			if (commandCode == None):
+				self._i2cbus.readfrom_into(address, buffer)
+			else:
+				self._i2cbus.writeto_then_readfrom(address, bytes([commandCode]), buffer)
 		except Exception as e:
 			self._i2cbus.unlock()
 			raise e
@@ -290,6 +299,26 @@ def writeBlock(self, address, commandCode, value):
 	def write_block(self, address, commandCode, value):
 		return self.writeBlock(address, commandCode, value)
 
+	def writeReadBlock(self, address, writeBytes, readNBytes):
+		read_buffer = bytearray(readNBytes)
+
+		if not self._i2cbus.try_lock():
+			raise Exception("Unable to lock I2C bus")
+		
+		try:
+			self._i2cbus.writeto_then_readfrom(address, bytes(writeBytes), read_buffer)
+		except Exception as e:
+			self._i2cbus.unlock()
+			raise e
+		else:
+			self._i2cbus.unlock()
+
+		return list(read_buffer)
+		
+	
+	def write_read_block(self, address, writeBytes, readNBytes):
+		return self.writeReadBlock(address, writeBytes, readNBytes)
+
 	def isDeviceConnected(self, devAddress):
 		if not self._i2cbus.try_lock():
 			raise Exception("Unable to lock I2C bus")
@@ -332,3 +361,4 @@ def scan(self):
 			self._i2cbus.unlock()
 
 		return devices
+	

qwiic_i2c/i2c_driver.py

@@ -126,7 +126,7 @@ def readWord(self, address, commandCode):
 			Called to read a word (16 bits) from a specific device.
 
 			:param address: The I2C address of the device to read from
-			:param commandCode: The "command" or register to read from 
+			:param commandCode: The "command" or register to read from, or `None` for no command
 
 			:return: Returns the read data
 			:rtype: integer - first 16 bits contain the read data. 
@@ -139,7 +139,7 @@ def read_word(self, address, commandCode):
 			Called to read a word (16 bits) from a specific device.
 
 			:param address: The I2C address of the device to read from
-			:param commandCode: The "command" or register to read from 
+			:param commandCode: The "command" or register to read from, or `None` for no command
 
 			:return: Returns the read data
 			:rtype: integer - first 16 bits contain the read data. 
@@ -152,7 +152,7 @@ def readByte(self, address, commandCode):
 			Called to read a byte (8 bits) from a specific device.
 
 			:param address: The I2C address of the device to read from
-			:param commandCode: The "command" or register to read from 
+			:param commandCode: The "command" or register to read from, or `None` for no command
 
 			:return: Returns the read data
 			:rtype: integer - first 8 bits contain the read data. 
@@ -165,7 +165,7 @@ def read_byte(self, address, commandCode):
 			Called to read a byte (8 bits) from a specific device.
 
 			:param address: The I2C address of the device to read from
-			:param commandCode: The "command" or register to read from 
+			:param commandCode: The "command" or register to read from, or `None` for no command
 
 			:return: Returns the read data
 			:rtype: integer - first 8 bits contain the read data. 
@@ -178,7 +178,7 @@ def readBlock(self, address, commandCode, nBytes):
 			Called to read a block of bytesfrom a specific device.
 
 			:param address: The I2C address of the device to read from
-			:param commandCode: The "command" or register to read from
+			:param commandCode: The "command" or register to read from, or `None` for no command
 			:param nBytes: The number of bytes to read from the device
 
 			:return: Returns the read data as a list of integers.
@@ -192,7 +192,7 @@ def read_block(self, address, commandCode, nBytes):
 			Called to read a block of bytesfrom a specific device.
 
 			:param address: The I2C address of the device to read from
-			:param commandCode: The "command" or register to read from
+			:param commandCode: The "command" or register to read from, or `None` for no command
 			:param nBytes: The number of bytes to read from the device
 
 			:return: Returns the read data as a list of integers.
@@ -312,6 +312,35 @@ def write_block(self, address, commandCode, value):
 
 		"""
 		return None
+	
+	def writeReadBlock(self, address, writeBytes, readNBytes):
+		""" 
+			Called to write a block of bytes to a device, send no stop bit, and then read a block of bytes.
+
+			:param address: The I2C address of the device to read from
+			:param writeBytes: A list of bytes (ints) to write on the I2C bus.
+			:param readNBytes: The number of bytes to read from the device
+
+			:return: A list of bytes read from the device.
+			:rtype: list
+
+		"""
+		return None
+	
+	def write_read_block(self, address, writeBytes, readNBytes):
+		""" 
+			Called to write a block of bytes to a device, send no stop bit, and then read a block of bytes.
+
+			:param address: The I2C address of the device to read from
+			:param writeBytes: A list of bytes (ints) to write on the I2C bus.
+			:param readNBytes: The number of bytes to read from the device
+
+			:return: A list of bytes read from the device.
+			:rtype: list
+
+		"""
+		return None
+
 
 	def isDeviceConnected(self, devAddress):
 		"""

qwiic_i2c/linux_i2c.py

@@ -151,14 +151,26 @@ def __setattr__(self, name, value):
 #-------------------------------------------------------------------------	
 	# read Data Command
 
+	# Performs a general read of <nBytes> from the device at <address> without a command/register code
+	# Linux doesn't support this directly like CircuitPython and MicroPython, so we have to read byte by byte
+	def _read_no_command(self, address, nBytes):
+		data = [0] * nBytes
+		for i in range(nBytes):
+			data = self._i2cbus.read_byte(address)
+			data[i] = data
+		return data
+
 	def readWord(self, address, commandCode):
 
 		data = 0
 
 		# add some error handling and recovery....
 		for i in range(_retry_count):
 			try:
-				data = self._i2cbus.read_word_data(address, commandCode)
+				if commandCode == None:
+					data = self._read_no_command(address, 2) # TODO: Check this, we may need to switch endianess
+				else:
+					data = self._i2cbus.read_word_data(address, commandCode)
 
 				break # break if try succeeds
 
@@ -199,7 +211,10 @@ def readBlock(self, address, commandCode, nBytes):
 		data = 0
 		for i in range(_retry_count):
 			try:
-				data = self._i2cbus.read_i2c_block_data(address, commandCode, nBytes)
+				if commandCode == None:
+					data = self._read_no_command(address, nBytes)
+				else:
+					data = self._i2cbus.read_i2c_block_data(address, commandCode, nBytes)
 
 				break # break if try succeeds
 
@@ -253,6 +268,12 @@ def writeBlock(self, address, commandCode, value):
 	def write_block(self, address, commandCode, value):
 		return self.writeBlock(address, commandCode, value)
 
+	def writeReadBlock(self, address, writeBytes, readNBytes):
+		return self.__i2c_rdwr__(address, writeBytes, readNBytes)
+	
+	def write_read_block(self, address, writeBytes, readNBytes):
+		return self.writeReadBlock(address, writeBytes, readNBytes)
+
 	def isDeviceConnected(self, devAddress):
 		isConnected = False
 		try:

qwiic_i2c/micropython_i2c.py

@@ -117,19 +117,29 @@ def __setattr__(self, name, value):
 
 	# read commands ----------------------------------------------------------
 	def readWord(self, address, commandCode):
-		buffer = self._i2cbus.readfrom_mem(address, commandCode, 2)
+		if (commandCode == None):
+			buffer = self._i2cbus.readfrom(address, 2)
+		else:
+			buffer = self._i2cbus.readfrom_mem(address, commandCode, 2)
+
 		return (buffer[1] << 8 ) | buffer[0]
 
 	def read_word(self, address, commandCode):
 		return self.readWord(address, commandCode)
 
-	def readByte(self, address, commandCode):
+	def readByte(self, address, commandCode = None):
+		if (commandCode == None):
+			return self._i2cbus.readfrom(address, 1)[0]
+
 		return self._i2cbus.readfrom_mem(address, commandCode, 1)[0]
 
 	def read_byte(self, address, commandCode = None):
 		return self.readByte(address, commandCode)
 
 	def readBlock(self, address, commandCode, nBytes):
+		if (commandCode == None):
+			return self._i2cbus.readfrom(address, nBytes)
+
 		return self._i2cbus.readfrom_mem(address, commandCode, nBytes)
 
 	def read_block(self, address, commandCode, nBytes):
@@ -160,6 +170,14 @@ def writeBlock(self, address, commandCode, value):
 	def write_block(self, address, commandCode, value):
 		return self.writeBlock(address, commandCode, value)
 
+	def writeReadBlock(self, address, writeBytes, readNBytes):
+		# micropython I2C doesn't have a corresponding "i2c_rdwr" function like smbus2, so we will make our own by passing stop=False to not send stop bits between repeated transfers
+		self._i2cbus.writeto(address, bytes(writeBytes), False)
+		return self._i2cbus.readfrom(address, readNBytes)
+	
+	def write_read_block(self, address, writeBytes, readNBytes):
+		return self.writeReadBlock(address, writeBytes, readNBytes)
+
 	def isDeviceConnected(self, devAddress):
 		isConnected = False
 		try: