92 lines
3.7 KiB
Python
92 lines
3.7 KiB
Python
################################################################################
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# #
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# This file is part of the Buildbotics firmware. #
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# #
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# Copyright (c) 2015 - 2018, Buildbotics LLC #
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# All rights reserved. #
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# #
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# This file ("the software") is free software: you can redistribute it #
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# and/or modify it under the terms of the GNU General Public License, #
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# version 2 as published by the Free Software Foundation. You should #
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# have received a copy of the GNU General Public License, version 2 #
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# along with the software. If not, see <http://www.gnu.org/licenses/>. #
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# #
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# The software is distributed in the hope that it will be useful, but #
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# WITHOUT ANY WARRANTY; without even the implied warranty of #
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU #
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# Lesser General Public License for more details. #
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# #
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# You should have received a copy of the GNU Lesser General Public #
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# License along with the software. If not, see #
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# <http://www.gnu.org/licenses/>. #
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# #
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# For information regarding this software email: #
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# "Joseph Coffland" <joseph@buildbotics.com> #
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# #
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################################################################################
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import errno
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try:
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try:
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import smbus
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except:
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import smbus2 as smbus
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except:
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smbus = None
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class I2C(object):
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def __init__(self, port, disabled):
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self.port = port
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self.i2c_bus = None
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self.disabled = disabled or smbus is None
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def connect(self):
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if self.disabled: return
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if self.i2c_bus is None:
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try:
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self.i2c_bus = smbus.SMBus(self.port)
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except OSError as e:
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self.i2c_bus = None
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if e.errno == errno.ENOENT: self.disabled = True
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else: raise type(e)('I2C failed to open device: %s' % e)
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def read_word(self, addr):
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self.connect()
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if self.disabled: return
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try:
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return self.i2c_bus.read_word_data(addr, 0)
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except IOError as e:
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self.i2c_bus.close()
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self.i2c_bus = None
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raise type(e)('I2C read word failed: %s' % e)
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def write(self, addr, cmd, byte = None, word = None, block = None):
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self.connect()
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if self.disabled: return
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try:
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if byte is not None:
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self.i2c_bus.write_byte_data(addr, cmd, byte)
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elif word is not None:
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self.i2c_bus.write_word_data(addr, cmd, word)
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elif block is not None:
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if isinstance(block, str): block = list(map(ord, block))
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self.i2c_bus.write_i2c_block_data(addr, cmd, block)
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else: self.i2c_bus.write_byte(addr, cmd)
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except IOError as e:
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self.i2c_bus.close()
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self.i2c_bus = None
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raise type(e)('I2C write failed: %s' % e)
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