klipper update

klippy/extras/mcp4451.py

@@ -0,0 +1,30 @@
+# MCP4451 digipot code
+#
+# Copyright (C) 2018  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+from . import bus
+
+WiperRegisters = [0x00, 0x01, 0x06, 0x07]
+
+class mcp4451:
+    def __init__(self, config):
+        self.i2c = bus.MCU_I2C_from_config(config)
+        i2c_addr = self.i2c.get_i2c_address()
+        if i2c_addr < 44 or i2c_addr > 47:
+            raise config.error("mcp4451 address must be between 44 and 47")
+        scale = config.getfloat('scale', 1., above=0.)
+        # Configure registers
+        self.set_register(0x04, 0xff)
+        self.set_register(0x0a, 0xff)
+        for i in range(4):
+            val = config.getfloat('wiper_%d' % (i,), None,
+                                  minval=0., maxval=scale)
+            if val is not None:
+                val = int(val * 255. / scale + .5)
+                self.set_register(WiperRegisters[i], val)
+    def set_register(self, reg, value):
+        self.i2c.i2c_write([(reg << 4) | ((value >> 8) & 0x03), value])
+
+def load_config_prefix(config):
+    return mcp4451(config)