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Diffstat (limited to 'Adafruit_Python_GPIO/Adafruit_GPIO/I2C.py')
| -rw-r--r-- | Adafruit_Python_GPIO/Adafruit_GPIO/I2C.py | 202 |
1 files changed, 0 insertions, 202 deletions
diff --git a/Adafruit_Python_GPIO/Adafruit_GPIO/I2C.py b/Adafruit_Python_GPIO/Adafruit_GPIO/I2C.py deleted file mode 100644 index 765ed82..0000000 --- a/Adafruit_Python_GPIO/Adafruit_GPIO/I2C.py +++ /dev/null @@ -1,202 +0,0 @@ -# Copyright (c) 2014 Adafruit Industries -# Author: Tony DiCola -# Based on Adafruit_I2C.py created by Kevin Townsend. -# -# 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. -import logging -import os -import subprocess - -import Adafruit_GPIO.Platform as Platform - - -def reverseByteOrder(data): - """DEPRECATED: See https://github.com/adafruit/Adafruit_Python_GPIO/issues/48""" - # # Courtesy Vishal Sapre - # byteCount = len(hex(data)[2:].replace('L','')[::2]) - # val = 0 - # for i in range(byteCount): - # val = (val << 8) | (data & 0xff) - # data >>= 8 - # return val - raise RuntimeError('reverseByteOrder is deprecated! See: https://github.com/adafruit/Adafruit_Python_GPIO/issues/48') - -def get_default_bus(): - """Return the default bus number based on the device platform. For a - Raspberry Pi either bus 0 or 1 (based on the Pi revision) will be returned. - For a Beaglebone Black the first user accessible bus, 1, will be returned. - """ - plat = Platform.platform_detect() - if plat == Platform.RASPBERRY_PI: - if Platform.pi_revision() == 1: - # Revision 1 Pi uses I2C bus 0. - return 0 - else: - # Revision 2 Pi uses I2C bus 1. - return 1 - elif plat == Platform.BEAGLEBONE_BLACK: - # Beaglebone Black has multiple I2C buses, default to 1 (P9_19 and P9_20). - return 1 - else: - raise RuntimeError('Could not determine default I2C bus for platform.') - -def get_i2c_device(address, busnum=None, i2c_interface=None, **kwargs): - """Return an I2C device for the specified address and on the specified bus. - If busnum isn't specified, the default I2C bus for the platform will attempt - to be detected. - """ - if busnum is None: - busnum = get_default_bus() - return Device(address, busnum, i2c_interface, **kwargs) - -def require_repeated_start(): - """Enable repeated start conditions for I2C register reads. This is the - normal behavior for I2C, however on some platforms like the Raspberry Pi - there are bugs which disable repeated starts unless explicitly enabled with - this function. See this thread for more details: - http://www.raspberrypi.org/forums/viewtopic.php?f=44&t=15840 - """ - plat = Platform.platform_detect() - if plat == Platform.RASPBERRY_PI and os.path.exists('/sys/module/i2c_bcm2708/parameters/combined'): - # On the Raspberry Pi there is a bug where register reads don't send a - # repeated start condition like the kernel smbus I2C driver functions - # define. As a workaround this bit in the BCM2708 driver sysfs tree can - # be changed to enable I2C repeated starts. - subprocess.check_call('chmod 666 /sys/module/i2c_bcm2708/parameters/combined', shell=True) - subprocess.check_call('echo -n 1 > /sys/module/i2c_bcm2708/parameters/combined', shell=True) - # Other platforms are a no-op because they (presumably) have the correct - # behavior and send repeated starts. - - -class Device(object): - """Class for communicating with an I2C device using the adafruit-pureio pure - python smbus library, or other smbus compatible I2C interface. Allows reading - and writing 8-bit, 16-bit, and byte array values to registers - on the device.""" - def __init__(self, address, busnum, i2c_interface=None): - """Create an instance of the I2C device at the specified address on the - specified I2C bus number.""" - self._address = address - if i2c_interface is None: - # Use pure python I2C interface if none is specified. - import Adafruit_PureIO.smbus - self._bus = Adafruit_PureIO.smbus.SMBus(busnum) - else: - # Otherwise use the provided class to create an smbus interface. - self._bus = i2c_interface(busnum) - self._logger = logging.getLogger('Adafruit_I2C.Device.Bus.{0}.Address.{1:#0X}' \ - .format(busnum, address)) - - def writeRaw8(self, value): - """Write an 8-bit value on the bus (without register).""" - value = value & 0xFF - self._bus.write_byte(self._address, value) - self._logger.debug("Wrote 0x%02X", - value) - - def write8(self, register, value): - """Write an 8-bit value to the specified register.""" - value = value & 0xFF - self._bus.write_byte_data(self._address, register, value) - self._logger.debug("Wrote 0x%02X to register 0x%02X", - value, register) - - def write16(self, register, value): - """Write a 16-bit value to the specified register.""" - value = value & 0xFFFF - self._bus.write_word_data(self._address, register, value) - self._logger.debug("Wrote 0x%04X to register pair 0x%02X, 0x%02X", - value, register, register+1) - - def writeList(self, register, data): - """Write bytes to the specified register.""" - self._bus.write_i2c_block_data(self._address, register, data) - self._logger.debug("Wrote to register 0x%02X: %s", - register, data) - - def readList(self, register, length): - """Read a length number of bytes from the specified register. Results - will be returned as a bytearray.""" - results = self._bus.read_i2c_block_data(self._address, register, length) - self._logger.debug("Read the following from register 0x%02X: %s", - register, results) - return results - - def readRaw8(self): - """Read an 8-bit value on the bus (without register).""" - result = self._bus.read_byte(self._address) & 0xFF - self._logger.debug("Read 0x%02X", - result) - return result - - def readU8(self, register): - """Read an unsigned byte from the specified register.""" - result = self._bus.read_byte_data(self._address, register) & 0xFF - self._logger.debug("Read 0x%02X from register 0x%02X", - result, register) - return result - - def readS8(self, register): - """Read a signed byte from the specified register.""" - result = self.readU8(register) - if result > 127: - result -= 256 - return result - - def readU16(self, register, little_endian=True): - """Read an unsigned 16-bit value from the specified register, with the - specified endianness (default little endian, or least significant byte - first).""" - result = self._bus.read_word_data(self._address,register) & 0xFFFF - self._logger.debug("Read 0x%04X from register pair 0x%02X, 0x%02X", - result, register, register+1) - # Swap bytes if using big endian because read_word_data assumes little - # endian on ARM (little endian) systems. - if not little_endian: - result = ((result << 8) & 0xFF00) + (result >> 8) - return result - - def readS16(self, register, little_endian=True): - """Read a signed 16-bit value from the specified register, with the - specified endianness (default little endian, or least significant byte - first).""" - result = self.readU16(register, little_endian) - if result > 32767: - result -= 65536 - return result - - def readU16LE(self, register): - """Read an unsigned 16-bit value from the specified register, in little - endian byte order.""" - return self.readU16(register, little_endian=True) - - def readU16BE(self, register): - """Read an unsigned 16-bit value from the specified register, in big - endian byte order.""" - return self.readU16(register, little_endian=False) - - def readS16LE(self, register): - """Read a signed 16-bit value from the specified register, in little - endian byte order.""" - return self.readS16(register, little_endian=True) - - def readS16BE(self, register): - """Read a signed 16-bit value from the specified register, in big - endian byte order.""" - return self.readS16(register, little_endian=False) |