From e6d82c7dcb4038e6aa55540e5bc996d205d975be Mon Sep 17 00:00:00 2001
From: Peter Hinch <peter@hinch.me.uk>
Date: Thu, 2 Nov 2023 15:15:41 +0000
Subject: [PATCH] Experimental encoder driver.

---
 gui/primitives/encoder.py | 44 +++++++++++++++++++++++++++++++--------
 1 file changed, 35 insertions(+), 9 deletions(-)

diff --git a/gui/primitives/encoder.py b/gui/primitives/encoder.py
index 759422b..64fbd35 100644
--- a/gui/primitives/encoder.py
+++ b/gui/primitives/encoder.py
@@ -11,21 +11,35 @@
 
 import uasyncio as asyncio
 from machine import Pin
+from . import Delay_ms
+
 
 class Encoder:
-
-    def __init__(self, pin_x, pin_y, v=0, div=1, vmin=None, vmax=None,
-                 mod=None, callback=lambda a, b : None, args=(), delay=100):
+    def __init__(
+        self,
+        pin_x,
+        pin_y,
+        v=0,
+        div=1,
+        vmin=None,
+        vmax=None,
+        mod=None,
+        callback=lambda a, b: None,
+        args=(),
+        delay=100,
+    ):
         self._pin_x = pin_x
         self._pin_y = pin_y
         self._x = pin_x()
         self._y = pin_y()
         self._v = v * div  # Initialise hardware value
         self._cv = v  # Current (divided) value
-        self.delay = delay  # Pause (ms) for motion to stop/limit callback frequency
+        self._delay = Delay_ms(duration=delay)
+        self._timeout = 2 * delay  # Continuous rotation timeout
+        # Pause (ms) for motion to stop/limit callback frequency
 
         if ((vmin is not None) and v < vmin) or ((vmax is not None) and v > vmax):
-            raise ValueError('Incompatible args: must have vmin <= v <= vmax')
+            raise ValueError("Incompatible args: must have vmin <= v <= vmax")
         self._tsf = asyncio.ThreadSafeFlag()
         trig = Pin.IRQ_RISING | Pin.IRQ_FALLING
         try:
@@ -34,7 +48,7 @@ class Encoder:
         except TypeError:  # hard arg is unsupported on some hosts
             xirq = pin_x.irq(trigger=trig, handler=self._x_cb)
             yirq = pin_y.irq(trigger=trig, handler=self._y_cb)
-        asyncio.create_task(self._run(vmin, vmax, div, mod, callback, args))
+        self._runt = asyncio.create_task(self._run(vmin, vmax, div, mod, callback, args))
 
     # Hardware IRQ's. Duration 36μs on Pyboard 1 ~50μs on ESP32.
     # IRQ latency: 2nd edge may have occured by the time ISR runs, in
@@ -51,15 +65,23 @@ class Encoder:
             self._v -= 1 if y ^ self._pin_x() else -1
             self._tsf.set()
 
+    async def respond(self):  # Retrigger the delay until motion/bounce stops
+        while True:
+            await self._tsf.wait()
+            self._delay.trigger()
+
     async def _run(self, vmin, vmax, div, mod, cb, args):
         pv = self._v  # Prior hardware value
         pcv = self._cv  # Prior divided value passed to callback
         lcv = pcv  # Current value after limits applied
         plcv = pcv  # Previous value after limits applied
-        delay = self.delay
+        self._rspt = asyncio.create_task(self.respond())
         while True:
-            await self._tsf.wait()
-            await asyncio.sleep_ms(delay)  # Wait for motion to stop.
+            try:
+                await asyncio.wait_for_ms(self._delay.wait(), self._timeout)
+            except asyncio.TimeoutError:  # Continuous rotation
+                pass
+            self._delay.clear()
             hv = self._v  # Sample hardware (atomic read).
             if hv == pv:  # A change happened but was negated before
                 continue  # this got scheduled. Nothing to do.
@@ -79,3 +101,7 @@ class Encoder:
 
     def value(self):
         return self._cv
+
+    def deinit(self):
+        self._rspt.cancel()
+        self._runt.cancel()