28 lines
930 B
Python
28 lines
930 B
Python
# MCP4451 digipot code
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#
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# Copyright (C) 2018 Kevin O'Connor <kevin@koconnor.net>
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#
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# This file may be distributed under the terms of the GNU GPLv3 license.
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import bus
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WiperRegisters = [0x00, 0x01, 0x06, 0x07]
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class mcp4451:
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def __init__(self, config):
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self.i2c = bus.MCU_I2C_from_config(config)
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scale = config.getfloat('scale', 1., above=0.)
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# Configure registers
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self.set_register(0x04, 0xff)
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self.set_register(0x0a, 0xff)
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for i in range(4):
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val = config.getfloat('wiper_%d' % (i,), None,
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minval=0., maxval=scale)
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if val is not None:
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val = int(val * 255. / scale + .5)
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self.set_register(WiperRegisters[i], val)
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def set_register(self, reg, value):
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self.i2c.i2c_write([(reg << 4) | ((value >> 8) & 0x03), value])
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def load_config_prefix(config):
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return mcp4451(config)
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