Rough, but working. Really needs electrical isolation/filtering

software/motion_controller/uencoder.py

@@ -0,0 +1,78 @@
+#
+# Minimal library for interfacing with encoder knobs such as the CYT1100
+#
+import machine
+from micropython import const
+
+
+# ENCODER
+# This Library assumes you are using a 3 pin encoder (2 outputs, and 1 ground).
+# The two outputs will be internally pulled up by the microcontroller. If the
+# Note: you can change the encoder direction by swapping the two output pins.
+
+
+# BUTTON
+# Some encoder knobs also allow for a down press (momentary button). These 
+# typically include two pins on the other side of the encoder. This library
+# assumes one of them will be grounded and the other will be internally pulled
+# up by the microcrontroller.
+
+
+
+class EncoderKnob(object):
+    """
+    Encoder Knob class. Handles reading the knob rotation and button press
+    """
+    def __init__(self, clk_pin, data_pin, btn_pin=None, rotary_callback=None, btn_callback=None):
+        """
+        @param clk_pin: one of the output pins from the encoder (will be internally pulled up)
+        @param data_pin: the other output pin of the encoder (will be internally pulled up)
+        @param btn_pin: (optional) if the encoder also includes a button (will be internally pulled up)
+        @param rotary_callback: (optional) Recommended, callback function accepting a single negative
+                                or positive integer for how much the knob rotated.
+        @param btn_callback: (optional) Recommended, callback accepting no arguments. Called every time
+                             the button is pressed (falling edge)
+        """
+        self.RotaryCallback = rotary_callback
+        self.ButtonCallback = btn_callback
+
+        self.Clk = machine.Pin(clk_pin, machine.Pin.IN, machine.Pin.PULL_UP)
+        self.Data = machine.Pin(data_pin, machine.Pin.IN, machine.Pin.PULL_UP)
+        if btn_pin:
+            self.Button = machine.Pin(btn_pin, machine.Pin.IN, machine.Pin.PULL_UP)
+            self.Button.irq(handler=self._handleButton, trigger=machine.Pin.IRQ_FALLING)
+        self.RawValue = 0
+        self.KnobValue = 0
+
+        self.LastState = 0
+
+        self.Clk.irq(handler=self._handlePins, trigger=machine.Pin.IRQ_RISING | machine.Pin.IRQ_FALLING)
+        self.Data.irq(handler=self._handlePins, trigger=machine.Pin.IRQ_RISING | machine.Pin.IRQ_FALLING)
+
+    def _handlePins(self, pin):
+        state = self.Clk.value()
+        change = 0
+        if state != self.LastState:
+            if self.Data.value() != state:
+                change = 1
+            else:
+                change = -1
+        
+            self.RawValue += change
+            self.KnobValue = int(self.RawValue / 2)
+
+            # The CYT1100 knob reads 2 pulses per click of the wheel
+            if change != 0 and self.RawValue % 2 == 0 and self.RotaryCallback:
+                self.RotaryCallback(change)
+        
+        self.LastState = state
+    
+    def _handleButton(self, pin):
+        if self.ButtonCallback:
+            self.ButtonCallback()
+    
+    def value(self):
+        """
+        @return: current value of the encoder
+        """
+        return self.KnobValue