Add class to use the module with an mcp port expander

Examples/example_mcp230xx.py

@@ -0,0 +1,34 @@
+# MIT License (MIT)
+# Copyright (c) 2024 Daniel Siegmanski
+# https://opensource.org/licenses/MIT
+
+# example for MicroPython rotary encoder connecten at an MCP23017
+
+from machine import I2C
+import mcp #MCP module from https://github.com/dsiggi/micropython-mcp230xx
+from rotary_irq_mcp230xx import RotaryIRQ
+import time
+
+i2c = I2C(0)
+io = mcp.MCP23017(i2c)
+
+# CLK pin connected to mcp at GPIOA 0
+# DT pin connected to mcp at GPIOA 1
+# INTA pin from mcp connected to ESP pin 15
+
+r = RotaryIRQ(mcp=io,
+              pin_num_clk=0,
+              pin_num_dt=1,
+              pin_num_int=15,
+              reverse=False,
+              range_mode=RotaryIRQ.RANGE_WRAP)
+
+val_old = r.value()
+while True:
+    val_new = r.value()
+
+    if val_old != val_new:
+        val_old = val_new
+        print('result =', val_new)
+
+    time.sleep_ms(50)

README.md

@@ -76,7 +76,15 @@ mpremote mip install github:miketeachman/micropython-rotary
 | ------------- | ------------- |
 | RotaryIRQ.RANGE_UNBOUNDED | encoder has no bounds on the counting range |
 | RotaryIRQ.RANGE_WRAP | encoder will count up to max_val then wrap to minimum value (similar behaviour for count down) |
-| RotaryIRQ.RANGE_BOUNDED |  encoder will count up to max_val then stop.  Count down stops at min_val |              
+| RotaryIRQ.RANGE_BOUNDED |  encoder will count up to max_val then stop.  Count down stops at min_val |  
+
+#### Special arguments for mcp version
+| argument       | description           | value |
+|-------------|-------------|---------|  
+| mcp | the mcp object to use | object (mcp module from https://github.com/dsiggi/micropython-mcp230xx) |
+| pin_num_clk | mcp GPIO pin connected to encoder CLK pin | integer |
+| pin_num_dt | GPIO pin connected to encoder DT pin |  integer |
+| pin_num_int | GPIO pin connected to mcp INTA/INTB pin | integer |
 
 ### Methods     
 `value()` Return the encoder value

rotary_irq_mcp230xx.py

@@ -0,0 +1,49 @@
+# The MIT License (MIT)
+# Copyright (c) 2024 Daniel Siegmanski
+# https://opensource.org/licenses/MIT
+
+# Platform-specific MicroPython code for the rotary encoder module
+# mcp23017 implementation
+
+# Documentation:
+#   https://github.com/MikeTeachman/micropython-rotary
+
+from .rotary import Rotary
+from machine import Pin
+
+class RotaryIRQ(Rotary): 
+
+    def __init__(self, mcp, pin_num_clk, pin_num_dt, pin_num_int, min_val=0, max_val=10, incr=1,
+                 reverse=False, range_mode=Rotary.RANGE_UNBOUNDED, pull_up=False, half_step=False, invert=False):
+
+        super().__init__(min_val, max_val, incr, reverse, range_mode, half_step, invert)
+
+        self.mcp = mcp
+        self.clk = pin_num_clk
+        self.dt = pin_num_dt
+
+        ### Configure MCP23017 ###
+        # Set CLK and DT pin as input
+        self.mcp.setup(self.clk, 1)
+        self.mcp.setup(self.dt, 1)
+		# enable pull ups
+        if pull_up:
+            self.mcp.pullup(self.clk, True)
+            self.mcp.pullup(self.dt, True)
+        # enable interrupt
+        self.mcp.set_interrupt(self.clk, True)
+        self.mcp.set_interrupt(self.dt, True)
+        self.mcp.configure(interrupt_polarity=True)
+
+		# interrupt pin, set as input
+        self.int_pin = Pin(pin_num_int, Pin.IN)
+        self.int_pin.irq(trigger=self.int_pin.IRQ_RISING, handler=self._process_rotary_pins)
+
+    def _hal_get_clk_value(self):
+        return self.mcp.read_captured_gpio()[self.clk]
+
+    def _hal_get_dt_value(self):
+        return self.mcp.read_captured_gpio()[self.dt]
+
+    def _hal_close(self):
+        self.int_pin.irq(handler=None)