Merge pull request #64 from jepler/incrementalencoder

Add a convenience class that mimics rotaryio.IncrementalEncoder in the core

Author: kattni

adafruit_seesaw/rotaryio.py

@@ -0,0 +1,35 @@
+# SPDX-FileCopyrightText: 2017 Dean Miller for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+
+# pylint: disable=missing-docstring,invalid-name,too-many-public-methods
+
+
+"""
+`adafruit_seesaw.digitalio`
+====================================================
+"""
+
+__version__ = "0.0.0-auto.0"
+__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_seesaw.git"
+
+
+class IncrementalEncoder:
+    """IncrementalEncoder determines the relative rotational position based
+    on two series of pulses."""
+
+    def __init__(self, seesaw, encoder=0):
+        """Create an IncrementalEncoder object associated with the given
+        eesaw device."""
+        self._seesaw = seesaw
+        self._encoder = encoder
+
+    @property
+    def position(self):
+        """The current position in terms of pulses. The number of pulses per
+        rotation is defined by the specific hardware."""
+        return self._seesaw.encoder_position(self._encoder)
+
+    @position.setter
+    def position(self, value):
+        self._seesaw.set_encoder_position(value, self._encoder)

examples/seesaw_rotary_simpletest.py

@@ -4,20 +4,27 @@
 import board
 from adafruit_seesaw.seesaw import Seesaw
 from adafruit_seesaw.digitalio import DigitalIO
+from adafruit_seesaw.rotaryio import IncrementalEncoder
 
 i2c_bus = board.I2C()
 
 seesaw = Seesaw(i2c_bus, addr=0x36)
 
+seesaw_product = (seesaw.get_version() >> 16) & 0xFFFF
+print("Found product {}".format(seesaw_product))
+if seesaw_product != 4991:
+    print("Wrong firmware loaded?  Expected 4991")
+
 button = DigitalIO(seesaw, 24)
 button_held = False
 
-last_position = seesaw.encoder_position()
+encoder = IncrementalEncoder(seesaw)
+last_position = None
 
 while True:
 
     # read position of the rotary encoder
-    position = seesaw.encoder_position()
+    position = encoder.position
     if position != last_position:
         last_position = position
         print("Position: {}".format(position))